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Sample records for squeezing molecularly thin

  1. Squeezing Molecularly thin Lubricant Films between curved Corrugated Surfaces with long range Elasticity

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    2010-01-01

    3H8, C4H10, C8H18, C9H20, C10H22, C14H30 and C16H34, confined between corrugated gold surfaces. Well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. An external squeezing pressure induces discontinuous, thermally activated changes...

  2. The effect of surface nano-corrugation on the squeeze-out of molecular thin hydrocarbon films between curved surfaces with long range elasticity

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Persson, Bo N. J.

    2016-01-01

    in the more disordered regions between these domains. The short alkanes stay fluid-like during the entire squeeze out process which result in a very small squeeze-out pressure which is almost constant during the squeeze-out of the last monolayer of the fluid. In all cases we observe lubricant trapped...

  3. Impact of molecular structure on the lubricant squeeze-out between curved surfaces with long range elasticity

    DEFF Research Database (Denmark)

    Tartaglino, Ugo; Sivebæk, Ion Marius; Persson, B N J

    2006-01-01

    layers develop in the lubricant film when the width is of the order of a few atomic diameters. The branched isobutane forms more disordered structures which permit it to stay liquidlike at smaller surface separations. During squeezing the solvation forces show oscillations corresponding to the width...... of a molecule. At low speeds (interfacial) squeezing velocity in most practical applications is very low when the lubricant layer has molecular thickness, one expects n-butane to be a better boundary lubricant than...

  4. Squeezing molecularly thin alkane lubrication films: Layering transistions and wear

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C(3)H(8); C(4)H(10); C(8)H(18); C(9)H(20); C(10)H...

  5. SQUEEZE-E: The Optimal Solution for Molecular Simulations with Periodic Boundary Conditions.

    Science.gov (United States)

    Wassenaar, Tsjerk A; de Vries, Sjoerd; Bonvin, Alexandre M J J; Bekker, Henk

    2012-10-09

    In molecular simulations of macromolecules, it is desirable to limit the amount of solvent in the system to avoid spending computational resources on uninteresting solvent-solvent interactions. As a consequence, periodic boundary conditions are commonly used, with a simulation box chosen as small as possible, for a given minimal distance between images. Here, we describe how such a simulation cell can be set up for ensembles, taking into account a priori available or estimable information regarding conformational flexibility. Doing so ensures that any conformation present in the input ensemble will satisfy the distance criterion during the simulation. This helps avoid periodicity artifacts due to conformational changes. The method introduces three new approaches in computational geometry: (1) The first is the derivation of an optimal packing of ensembles, for which the mathematical framework is described. (2) A new method for approximating the α-hull and the contact body for single bodies and ensembles is presented, which is orders of magnitude faster than existing routines, allowing the calculation of packings of large ensembles and/or large bodies. 3. A routine is described for searching a combination of three vectors on a discretized contact body forming a reduced base for a lattice with minimal cell volume. The new algorithms reduce the time required to calculate packings of single bodies from minutes or hours to seconds. The use and efficacy of the method is demonstrated for ensembles obtained from NMR, MD simulations, and elastic network modeling. An implementation of the method has been made available online at http://haddock.chem.uu.nl/services/SQUEEZE/ and has been made available as an option for running simulations through the weNMR GRID MD server at http://haddock.science.uu.nl/enmr/services/GROMACS/main.php .

  6. Quantum Squeezing

    International Nuclear Information System (INIS)

    Zubairy, Suhail

    2005-01-01

    Quantum squeezed states are a consequence of uncertainty relations; a state is squeezed when the noise in one variable is reduced below the symmetric limit at the expense of the increased noise in the conjugate variable such that the Heisenberg uncertainty relation is not violated. Such states have been known since the earliest days of quantum mechanics. The realization in the early 80's that quantum squeezed states of the radiation field can have important applications in high precision Michelson interferometry for detecting gravitational waves led to a tremendous amount of activity, both in theoretical and experimental quantum optics. The present volume, edited by two eminent scientists, is a collection of papers by leading experts in the field of squeezed states on different aspects of the field as it stands today. The book is divided into three parts. In the first part, there are three articles that review the fundamentals. The first paper by Knight and Buzek presents an introductory account of squeezed states and their properties. The chapter, which opens with the quantization of the radiation field, goes on to discuss the quantum optical properties of single mode and multimode squeezed states. The second article by Hillery provides a detailed description of field quantization in the presence of a nonlinear dielectric medium, thus providing a rigorous treatment of squeezing in nonlinear media. The third article by Yurke presents a comprehensive discussion of the input-output theory of the squeezed radiation at the dielectric boundaries. The second part of the book, comprising of three articles, deals with the generation of squeezed states. In the first article, Drummond reviews the squeezing properties of light in nonlinear systems such as parametric oscillators. He also discusses squeezed light propagation through waveguides and optical fibers. In the second article, Ralph concentrates on active laser sources of squeezing and presents an analysis based on the

  7. Second-order Monte Carlo wave-function approach to the relaxation effects on ringing revivals in a molecular system interacting with a strongly squeezed coherent field

    International Nuclear Information System (INIS)

    Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Yamaguchi, Kizashi

    2004-01-01

    We investigate the relaxation effects on the quantum dynamics in a two-state molecular system interacting with a single-mode strongly amplitude-squeezed coherent field using the second-order Monte Carlo wave-function method. The molecular population inversion (collapse-revival behavior of Rabi oscillations) is known to show the echoes after each revival, which are referred to as ringing revivals, in the case of strongly squeezed coherent fields with oscillatory photon-number distributions due to the phase-space interference effect. Two types of relaxation effects, i.e., cavity relaxation (the dissipation of an internal single mode to outer mode) and molecular coherent (phase) relaxation caused by nuclear vibrations on ringing revivals are investigated from the viewpoint of the quantum-phase dynamics using the quasiprobability (Q function) distribution of a single-mode field and the off-diagonal molecular density matrix ρ elec1,2 (t). It turns out that the molecular phase relaxation attenuates both the entire revival-collapse behavior and the increase in ρ elec1,2 (t) during the quiescent region, whereas a very slight cavity relaxation particularly suppresses the echoes in ringing revivals more significantly than the first revival but hardly changes a primary variation in envelope of ρ elec1,2 (t) in the nonrelaxation case

  8. Toward a compact fibered squeezing parametric source.

    Science.gov (United States)

    Brieussel, Alexandre; Ott, Konstantin; Joos, Maxime; Treps, Nicolas; Fabre, Claude

    2018-03-15

    In this work, we investigate three different compact fibered systems generating vacuum squeezing that involve optical cavities limited by the end surface of a fiber and by a curved mirror and containing a thin parametric crystal. These systems have the advantage to couple squeezed states directly to a fiber, allowing the user to benefit from the flexibility of fibers in the use of squeezing. Three types of fibers are investigated: standard single-mode fibers, photonic-crystal large-mode-area single-mode fibers, and short multimode fibers taped to a single-mode fiber. The observed squeezing is modest (-0.56  dB, -0.9  dB, -1  dB), but these experiments open the way for miniaturized squeezing devices that could be a very interesting advantage in scaling up quantum systems for quantum processing, opening new perspectives in the domain of integrated quantum optics.

  9. Control of Squeezed States

    OpenAIRE

    Bloch, Anthony M.; Rojo, Alberto G.

    2000-01-01

    In this paper we consider the classical and quantum control of squeezed states of harmonic oscillators. This provides a method for reducing noise below the quantum limit and provides an example of the control of under-actuated systems in the stochastic and quantum context. We consider also the interaction of a squeezed quantum oscillator with an external heat bath.

  10. Molecular simulation of freestanding amorphous nickel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dong, T.Q. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France); Hoang, V.V., E-mail: vvhoang2002@yahoo.com [Department of Physics, Institute of Technology, National University of Ho Chi Minh City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Lauriat, G. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, UMR 8208 CNRS, 5 Boulevard Descartes, 77454 Marne-la-Vallée, Cedex 2 (France)

    2013-10-31

    Size effects on glass formation in freestanding Ni thin films have been studied via molecular dynamics simulation with the n-body Gupta interatomic potential. Atomic mechanism of glass formation in the films is determined via analysis of the spatio-temporal arrangements of solid-like atoms occurred upon cooling from the melt. Solid-like atoms are detected via the Lindemann ratio. We find that solid-like atoms initiate and grow mainly in the interior of the film and grow outward. Their number increases with decreasing temperature and at a glass transition temperature they dominate in the system to form a relatively rigid glassy state of a thin film shape. We find the existence of a mobile surface layer in both liquid and glassy states which can play an important role in various surface properties of amorphous Ni thin films. We find that glass formation is size independent for models containing 4000 to 108,000 atoms. Moreover, structure of amorphous Ni thin films has been studied in details via coordination number, Honeycutt–Andersen analysis, and density profile which reveal that amorphous thin films exhibit two different parts: interior and surface layer. The former exhibits almost the same structure like that found for the bulk while the latter behaves a more porous structure containing a large amount of undercoordinated sites which are the origin of various surface behaviors of the amorphous Ni or Ni-based thin films found in practice. - Highlights: • Glass formation is analyzed via spatio-temporal arrangements of solid-like atoms. • Amorphous Ni thin film exhibits two different parts: surface and interior. • Mobile surface layer enhances various surface properties of the amorphous Ni thin films. • Undercoordinated sites play an important role in various surface activities.

  11. The transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

    Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

    1980-01-01

    We present new results on the transmission of fast molecular ions through thin foils and propose a mechanism for the transmission process. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target. (orig.)

  12. Transmission of fast molecular ions through thin foils

    International Nuclear Information System (INIS)

    Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

    1979-01-01

    New results on the transmission of fast molecular ions through thin foils are presented and a mechanism for the transmission process is proposed. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target

  13. Squeezed between shells? The origin of the Lupus I molecular cloud. II. APEX CO and GASS H I observations

    Science.gov (United States)

    Gaczkowski, B.; Roccatagliata, V.; Flaischlen, S.; Kröll, D.; Krause, M. G. H.; Burkert, A.; Diehl, R.; Fierlinger, K.; Ngoumou, J.; Preibisch, T.

    2017-12-01

    Context. Lupus I cloud is found between the Upper Scorpius (USco) and Upper Centaurus-Lupus (UCL) subgroups of the Scorpius-Centaurus OB association, where the expanding USco H I shell appears to interact with a bubble currently driven by the winds of the remaining B stars of UCL. Aims: We investigate whether the Lupus I molecular could have formed in a colliding flow, and in particular, how the kinematics of the cloud might have been influenced by the larger scale gas dynamics. Methods: We performed APEX 13CO(2-1)and C18O(2-1) line observations of three distinct parts of Lupus I that provide kinematic information on the cloud at high angular and spectral resolution. We compare those results to the atomic hydrogen data from the GASS H I survey and our dust emission results presented in the previous paper. Based on the velocity information, we present a geometric model for the interaction zone between the USco shell and the UCL wind bubble. Results: We present evidence that the molecular gas of Lupus Iis tightly linked to the atomic material of the USco shell. The CO emission in Lupus Iis found mainly at velocities between vLSR = 3-6 km s-1, which is in the same range as the H I velocities. Thus, the molecular cloud is co-moving with the expanding USco atomic H I shell. The gas in the cloud shows a complex kinematic structure with several line-of-sight components that overlay each other. The nonthermal velocity dispersion is in the transonic regime in all parts of the cloud and could be injected by external compression. Our observations and the derived geometric model agree with a scenario in which Lupus Iis located in the interaction zone between the USco shell and the UCL wind bubble. Conclusions: The kinematics observations are consistent with a scenario in which the Lupus Icloud formed via shell instabilities. The particular location of Lupus I between USco and UCL suggests that counterpressure from the UCL wind bubble and pre-existing density enhancements

  14. Properties of squeezed Schroedinger cats

    International Nuclear Information System (INIS)

    Obada, A.S.F.; Omar, Z.M.

    1995-09-01

    In this article we investigate some statistical properties of the even and odd squeezed (squeezed Schroedinger cat) states. The quasi-probability distribution functions especially W(α) and Q(α) are calculated and discussed for these states. The phase distribution function is discussed. A generation scheme is proposed for either the squeezed generalized Schroedinger cat, or the squeezed number state. (author). 35 refs, 5 figs

  15. Spin squeezing and quantum correlations

    Indian Academy of Sciences (India)

    2 states. A coherent spin-s state. (CSS) θ φ can then be thought of as having no quantum correlations as the constituent. 2s elementary spins point in the same direction ˆn(θ φ) which is the mean spin direction. 2. State classification and squeezing. In order to discuss squeezing, we begin with the squeezing condition itself.

  16. The effect of solvent upon molecularly thin rotaxane film formation

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Alan A. [Nanoscale Function Group, Centre for Research on Adaptive Nanostructures and Nanodevices, University of Dublin, Trinity College, Dublin 2 (Ireland)]. E-mail: farrelaa@tcd.ie; Kay, Euan R. [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Bottari, Giovanni [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Leigh, David A. [School of Chemistry, University of Edinburgh, The King' s Buildings, West Mains Road, Edinburgh EH9 3 JJ (United Kingdom); Jarvis, Suzanne P. [Nanoscale Function Group, Centre for Research on Adaptive Nanostructures and Nanodevices, University of Dublin, Trinity College, Dublin 2 (Ireland)

    2007-05-15

    We have investigated variations in molecularly thin rotaxane films deposited by solvent evaporation, using atomic force microscopy (AFM). Small changes in rotaxane structure result in significant differences in film morphology. The addition of exo-pyridyl moietes to the rotaxane macrocycle results in uniform domains having orientations corresponding to the underlying substrate lattice, while a larger, less symmetric molecule results in a greater lattice mismatch and smaller domain sizes. We have measured differences in film heights both as a function of the solvent of deposition and as a function of surface coverage of rotaxanes. Based on these observations we describe how the use of solvents with higher hydrogen-bond basicity results in films which are more likely to favour sub-molecular motion.

  17. The magnetohydrodynamic squeeze film

    International Nuclear Information System (INIS)

    Hamza, E.A.

    1987-06-01

    The motion of an electrically conducting fluid film squeezed between two parallel disks in the presence of a magnetic field applied perpendicular to the disks is studied. Analytic solutions through use of a regular perturbation scheme are obtained. The results show that the electromagnetic forces increase the load carrying capacity considerably. (author). 5 refs, 10 figs, 3 tabs

  18. Phase squeezed states

    International Nuclear Information System (INIS)

    Chizhov, A.V.; Paris, M.G.A.

    1998-01-01

    Phase squeezed states of a single mode radiation field have been introduced as eigenstates of a linear combination of lowering and raising operators. The explicit expression in the Fock basis has been obtained and some relevant properties have been illustrated. (author)

  19. Thermalization of squeezed states

    International Nuclear Information System (INIS)

    Solomon, Allan I

    2005-01-01

    Starting with a thermal squeezed state defined as a conventional thermal state based on an appropriate Hamiltonian, we show how an important physical property, the signal-to-noise ratio, is degraded, and propose a simple model of thermalization (Kraus thermalization)

  20. Squeezing molecular thin alkane lubrication films between curved solid surfaces with long-range elasticity: Layering transitions and wear

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

    2003-01-01

    The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C3H8, C4H10, C8H18, C9H20, C10H22, C12H26 and C14...

  1. Molecular tailoring of interfaces for thin film on substrate systems

    Science.gov (United States)

    Grady, Martha Elizabeth

    Thin film on substrate systems appear most prevalently within the microelectronics industry, which demands that devices operate in smaller and smaller packages with greater reliability. The reliability of these multilayer film systems is strongly influenced by the adhesion of each of the bimaterial interfaces. During use, microelectronic components undergo thermo-mechanical cycling, which induces interfacial delaminations leading to failure of the overall device. The ability to tailor interfacial properties at the molecular level provides a mechanism to improve thin film adhesion, reliability and performance. This dissertation presents the investigation of molecular level control of interface properties in three thin film-substrate systems: photodefinable polyimide films on passivated silicon substrates, self-assembled monolayers at the interface of Au films and dielectric substrates, and mechanochemically active materials on rigid substrates. For all three materials systems, the effect of interfacial modifications on adhesion is assessed using a laser-spallation technique. Laser-induced stress waves are chosen because they dynamically load the thin film interface in a precise, noncontacting manner at high strain rates and are suitable for both weak and strong interfaces. Photodefinable polyimide films are used as dielectrics in flip chip integrated circuit packages to reduce the stress between silicon passivation layers and mold compound. The influence of processing parameters on adhesion is examined for photodefinable polyimide films on silicon (Si) substrates with three different passivation layers: silicon nitride (SiNx), silicon oxynitride (SiOxNy), and the native silicon oxide (SiO2). Interfacial strength increases when films are processed with an exposure step as well as a longer cure cycle. Additionally, the interfacial fracture energy is assessed using a dynamic delamination protocol. The high toughness of this interface (ca. 100 J/m2) makes it difficult

  2. Porous squeeze-film flow

    KAUST Repository

    Knox, D. J.

    2013-11-14

    © 2013 © The authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved. The squeeze-film flow of a thin layer of Newtonian fluid filling the gap between a flat impermeable surface moving under a prescribed constant load and a flat thin porous bed coating a stationary flat impermeable surface is considered. Unlike in the classical case of an impermeable bed, in which an infinite time is required for the two surfaces to touch, for a porous bed contact occurs in a finite contact time. Using a lubrication approximation, an implicit expression for the fluid layer thickness and an explicit expression for the contact time are obtained and analysed. In addition, the fluid particle paths are calculated, and the penetration depths of fluid particles into the porous bed are determined. In particular, the behaviour in the asymptotic limit of small permeability, in which the contact time is large but finite, is investigated. Finally, the results are interpreted in the context of lubrication in the human knee joint, and some conclusions are drawn about the contact time of the cartilage-coated femoral condyles and tibial plateau and the penetration of nutrients into the cartilage.

  3. Measurement of incident molecular temperature in the formation of organic thin films

    Science.gov (United States)

    Abe, Takahiro; Matsubara, Ryosuke; Hayakawa, Munetaka; Shimoyama, Akifumi; Tanaka, Takaaki; Tsuji, Akira; Takahashi, Yoshikazu; Kubono, Atsushi

    2018-03-01

    To investigate the effects of incident molecular temperature on organic-thin-film growth by vacuum evaporation, quantitative analysis of molecular temperature is required. In this study, we propose a method of determining molecular temperature based on the heat exchange between a platinum filament and molecular vapor. Molecular temperature is estimated from filament temperature, which remains unchanged even under molecular vapor supply. The results indicate that our method has sufficient sensitivity to evaluate the molecular temperature under the typical growth rate used for fabrication of functional organic thin films.

  4. Correlation measurement of squeezed light

    DEFF Research Database (Denmark)

    Krivitsky, Leonid; Andersen, Ulrik Lund; Dong, R.

    2009-01-01

    We study the implementation of a correlation measurement technique for the characterization of squeezed light which is nearly free of electronic noise. With two different sources of squeezed light, we show that the sign of the covariance coefficient, revealed from the time-resolved correlation data......, is witnessing the presence of squeezing in the system. Furthermore, we estimate the degree of squeezing using the correlation method and compare it to the standard homodyne measurement scheme. We show that the role of electronic detector noise is minimized using the correlation approach as opposed to homodyning...

  5. Squeezing-out dynamics in free-standing smectic films

    Energy Technology Data Exchange (ETDEWEB)

    S̀liwa, Izabela, E-mail: izasliwa@ifmpan.poznan.pl [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznaǹ (Poland); Vakulenko, A.A. [Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178 (Russian Federation); Zakharov, A.V., E-mail: alexandre.zakharov@yahoo.ca [Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178 (Russian Federation)

    2016-05-06

    Highlights: • We model the dynamics of layer transitions. • We model the thermally activated nucleation of a small hole. • We model the dynamics of squeezing-out one layer. - Abstract: We have carried out a theoretical study of the dynamics of the squeezing-out of one layer from the N-layer free-standing smectic film (FSSF) coupled with a meniscus, during the layer-thinning process. Squeezing-out is initiated by a thermally activated nucleation process in which a density fluctuation forms a small void in the center of the circular FSSF. The pressure gradient develops between the squeezed-out and nonsqueezed-out areas and is responsible for the driving out of one or several layer(s) from the N-layer smectic film. The dynamics of the boundary between these areas in the FSSF is studied by the use of the conservation laws for mass and linear momentum with accounting for the coupling between the meniscus and the smectic film. This coupling has a strong effect on the dynamics of the squeezing-out process and may significantly change the time which is needed to completely squeezed-out one or several layer(s) from the N-layer smectic film.

  6. Supercritical fluid molecular spray thin films and fine powders

    Science.gov (United States)

    Smith, Richard D.

    1988-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. The solvent is vaporized and pumped away. Solution pressure is varied to determine, together with flow rate, the rate of deposition and to control in part whether a film or powder is produced and the granularity of each. Solution temperature is varied in relation to formation of a two-phase system during expansion to control porosity of the film or powder. A wide variety of film textures and powder shapes are produced of both organic and inorganic compounds. Films are produced with regular textural feature dimensions of 1.0-2.0 .mu.m down to a range of 0.01 to 0.1 .mu.m. Powders are formed in very narrow size distributions, with average sizes in the range of 0.02 to 5 .mu.m.

  7. Supersqueezed states from squeezed states

    International Nuclear Information System (INIS)

    Nieto, M.M.

    1992-01-01

    Using super-Baker-Campbell-Hausdorff relations on the elements of the supergroup OSP(2/2), we derive the supersqueeze operator and the supersqueezed states, which are the supersymmetric generalization of the squeezed states of the harmonic oscillator

  8. Qutrit squeezing via semiclassical evolution

    International Nuclear Information System (INIS)

    Klimov, Andrei B; Dinani, Hossein Tavakoli; Medendorp, Zachari E D; Guise, Hubert de

    2011-01-01

    We introduce a concept of squeezing in collective qutrit systems through a geometrical picture connected to the deformation of the isotropic fluctuations of su(3) operators when evaluated in a coherent state. This kind of squeezing can be generated by Hamiltonians nonlinear in the generators of su(3) algebra. A simplest model of such a nonlinear evolution is analyzed in terms of semiclassical evolution of the SU(3) Wigner function. (paper)

  9. The LHC, de-squeezed

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    Rare processes like the Higgs production require maximizing the number of proton collisions. This is done by squeezing the beams to very small sizes. However, interesting physics processes also happen when beams are not squeezed at interaction points. Last week, a dedicated run showed that the LHC is a record-breaking machine also with de-squeezed beams.   This figure shows an online hit map of one of the ATLAS/ALFA detectors. The narrow elliptical shape is the typical signal produced by elastically scattered protons. The removal of the background (central bulge) is a challenge for both experiments. The beam squeezing parameter is known by experts as beta-star (ß*): the smaller the ß*, the stronger the squeezing. To obtain as many collisions as possible in the heart of the experiments, the ß* at full energy is 0.60 m – that is, beams are squeezed to very small beam sizes. This maximizes the rate of proton collisions as required for rare process...

  10. What are squeezed states really like

    International Nuclear Information System (INIS)

    Nieto, M.M.

    1984-01-01

    The simple harmonic oscillator and some quantum mechanics are reviewed. Then a special case of the squeezed states, the coherent states, is discussed. Next, the coherent states are described from the operator formalism. The squeezed states are described from the Schroedinger point of view, and their properties are discussed. Harmonic motion and coherent and squeezed states are discussed for general potentials. Then the (harmonic oscillator) squeezed states are discussed from the operator point of view and some of their mathematical properties

  11. Squeezed light in optomechanical systems

    DEFF Research Database (Denmark)

    Harris, G. I.; Taylor, M. A.; Hoff, Ulrich Busk

    2012-01-01

    Squeezed light enhanced optomechanical measurements are demonstrated in both intra-cavity and biological contexts, with respective enhancements of 1.0 and 2.7 dB. Quantum enhanced microrheology of the cytoplasm of a yeast cell is thereby realized.......Squeezed light enhanced optomechanical measurements are demonstrated in both intra-cavity and biological contexts, with respective enhancements of 1.0 and 2.7 dB. Quantum enhanced microrheology of the cytoplasm of a yeast cell is thereby realized....

  12. Squeezed colour states in gluon jet

    Science.gov (United States)

    Kilin, S. YA.; Kuvshinov, V. I.; Firago, S. A.

    1993-01-01

    The possibility of the formation of squeezed states of gluon fields in quantum chromodynamics due to nonlinear nonperturbative self interaction during jet evolution in the process of e(+)e(-) annihilation into hadrons, which are analogous to the quantum photon squeezed states in quantum electrodynamics, is demonstrated. Additionally, the squeezing parameters are calculated.

  13. 30 years of squeezed light generation

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Gehring, Tobias; Marquardt, Christoph

    2016-01-01

    Squeezed light generation has come of age. Significant advances on squeezed light generation have been made over the last 30 years—from the initial, conceptual experiment in 1985 till today’s top-tuned, application-oriented setups. Here we review the main experimental platforms for generating...... quadrature squeezed light that have been investigated in the last 30 years....

  14. Experiment-scale molecular simulation study of liquid crystal thin films

    Science.gov (United States)

    Nguyen, Trung Dac; Carrillo, Jan-Michael Y.; Matheson, Michael A.; Brown, W. Michael

    2014-03-01

    Supercomputers have now reached a performance level adequate for studying thin films with molecular detail at the relevant scales. By exploiting the power of GPU accelerators on Titan, we have been able to perform simulations of characteristic liquid crystal films that provide remarkable qualitative agreement with experimental images. We have demonstrated that key features of spinodal instability can only be observed with sufficiently large system sizes, which were not accessible with previous simulation studies. Our study emphasizes the capability and significance of petascale simulations in providing molecular-level insights in thin film systems as well as other interfacial phenomena.

  15. Finite Element Analysis of Laser Engineered Net Shape (LENS™) Tungsten Clad Squeeze Pins

    Science.gov (United States)

    Sakhuja, Amit; Brevick, Jerald R.

    2004-06-01

    In the aluminum high-pressure die-casting and indirect squeeze casting processes, local "squeeze" pins are often used to minimize internal solidification shrinkage in heavy casting sections. Squeeze pins frequently fail in service due to molten aluminum adhering to the H13 tool steel pins ("soldering"). A wide variety of coating materials and methods have been developed to minimize soldering on H13. However, these coatings are typically very thin, and experience has shown their performance on squeeze pins is highly variable. The LENS™ process was employed in this research to deposit a relatively thick tungsten cladding on squeeze pins. An advantage of this process was that the process parameters could be precisely controlled in order to produce a satisfactory cladding. Two fixtures were designed and constructed to enable the end and outer diameter (OD) of the squeeze pins to be clad. Analyses were performed on the clad pins to evaluate the microstructure and chemical composition of the tungsten cladding and the cladding-H13 substrate interface. A thermo-mechanical finite element analysis (FEA) was performed to assess the stress distribution as a function of cladding thickness on the pins during a typical casting thermal cycle. FEA results were validated via a physical test, where the clad squeeze pins were immersed into molten aluminum. Pins subjected to the test were evaluated for thermally induced cracking and resistance to soldering of the tungsten cladding.

  16. Finite element analysis of laser engineered net shape (LENSTM) tungsten clad squeeze pins

    International Nuclear Information System (INIS)

    Sakhuja, Amit; Brevick, Jerald R.

    2004-01-01

    In the aluminum high-pressure die-casting and indirect squeeze casting processes, local 'squeeze' pins are often used to minimize internal solidification shrinkage in heavy casting sections. Squeeze pins frequently fail in service due to molten aluminum adhering to the H13 tool steel pins ('soldering'). A wide variety of coating materials and methods have been developed to minimize soldering on H13. However, these coatings are typically very thin, and experience has shown their performance on squeeze pins is highly variable. The LENS TM process was employed in this research to deposit a relatively thick tungsten cladding on squeeze pins. An advantage of this process was that the process parameters could be precisely controlled in order to produce a satisfactory cladding. Two fixtures were designed and constructed to enable the end and outer diameter (OD) of the squeeze pins to be clad. Analyses were performed on the clad pins to evaluate the microstructure and chemical composition of the tungsten cladding and the cladding-H13 substrate interface. A thermo-mechanical finite element analysis (FEA) was performed to assess the stress distribution as a function of cladding thickness on the pins during a typical casting thermal cycle. FEA results were validated via a physical test, where the clad squeeze pins were immersed into molten aluminum. Pins subjected to the test were evaluated for thermally induced cracking and resistance to soldering of the tungsten cladding

  17. Thin films of molecular metals TTF-TCNQ

    International Nuclear Information System (INIS)

    Fraxedas, J.; Molas, S.; Figueras, A.; Jimenez, I.; Gago, R.; Auban-Senzier, P.; Goffman, M.

    2002-01-01

    We present recent results on the characterization of highly ordered polycrystalline thin films of the charge transfer salt TTF-TCNQ (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) prepared by thermal sublimation in high vacuum under different conditions. The increase in orientation and microcrystal size as a function of substrate and annealing temperatures is addressed. A consequence of such an increase is the reduction of the conductivity activation energy, which eventually leads to the observation of the Peierls transition by resistivity measurements. X-ray absorption near edge spectroscopy studies performed with synchrotron radiation reveal directly the influence of charge transfer on unoccupied states near the Fermi level

  18. Thin films of molecular metals TTF-TCNQ

    CERN Document Server

    Fraxedas, J; Figueras, A; Jimenez, I; Gago, R; Auban-Senzier, P; Goffman, M

    2002-01-01

    We present recent results on the characterization of highly ordered polycrystalline thin films of the charge transfer salt TTF-TCNQ (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) prepared by thermal sublimation in high vacuum under different conditions. The increase in orientation and microcrystal size as a function of substrate and annealing temperatures is addressed. A consequence of such an increase is the reduction of the conductivity activation energy, which eventually leads to the observation of the Peierls transition by resistivity measurements. X-ray absorption near edge spectroscopy studies performed with synchrotron radiation reveal directly the influence of charge transfer on unoccupied states near the Fermi level.

  19. Squeezing via two-photon transitions

    Science.gov (United States)

    Savage, C. M.; Walls, D. F.

    1986-05-01

    The squeezing spectrum for a cavity field mode interacting with an ensemble of three-level 'Lambda-configuration' atoms by an effective two-photon transition is calculated. The advantage of the three-level Lambda system as a squeezing medium, that is, optical nonlinearity without atomic saturation, has recently been pointed out by Reid, Walls, and Dalton. Perfect squeezing is predicted at the turning points for dispersive optical bistability and good squeezing for a range of other cases. Three-level ladder atoms interacting by an effective two-photon transition are also shown to give perfect squeezing in the dispersive limit.

  20. Non-Markovian reservoir-dependent squeezing

    International Nuclear Information System (INIS)

    Paavola, J

    2010-01-01

    The squeezing dynamics of a damped harmonic oscillator are studied for different types of environment without making the Markovian approximation. The squeezing dynamics of a coherent state depend on the reservoir spectrum in a unique way that can, in the weak coupling approximation, be analysed analytically. Comparison of squeezing dynamics for ohmic, sub-ohmic and super-ohmic environments is done, showing a clear connection between the squeezing-non-squeezing oscillations and reservoir structure. Understanding the effects occurring due to structured reservoirs is important both from a purely theoretical point of view and in connection with evolving experimental techniques and future quantum computing applications.

  1. Molecular dynamics simulation of thin film interfacial strength dependency on lattice mismatch

    International Nuclear Information System (INIS)

    Yang, Zhou; Lian, Jie; Wang, Junlan

    2013-01-01

    Laser-induced thin film spallation experiments have been previously developed to characterize the intrinsic interfacial strength of thin films. In order to gain insights of atomic level thin film debonding processes and the interfacial strength dependence on film/substrate lattice structures, in this study, molecular dynamics simulations of thin film interfacial failure under laser-induced stress waves were performed. Various loading amplitudes and pulse durations were employed to identify the optimum simulation condition. Stress propagation as a function of time was revealed in conjunction with the interface structures. Parametric studies confirmed that while the interfacial strength between a thin film and a substrate does not depend on the film thickness and the duration of the laser pulse, a thicker film and a shorter duration do provide advantage to effectively load the interface to failure. With the optimized simulation condition, further studies were focused on bulk Au/Au bi-crystals with mismatched orientations, and Ni/Al, Cu/Al, Cu/Ag and Cu/Au bi-crystals with mismatched lattices. The interfacial strength was found to decrease with increasing orientation mismatch and lattice mismatch but more significantly dominated by the bonding elements' atomic structure and valence electron occupancy. - Highlights: • Molecular dynamics simulation was done on stress wave induced thin film spallation. • Atomic structure was found to be a primary strength determining factor. • Lattice mismatch was found to be a secondary strength determining factor

  2. Thin films of molecular materials synthesized from fisher's carbene ferrocenyl: Film formation and electrical properties

    International Nuclear Information System (INIS)

    Sanchez-Vergara, M.E.; Ortiz, A.; Alvarez-Toledano, C.; Moreno, A.; Alvarez, J.R.

    2008-01-01

    The synthesis of materials from Fisher's carbene ferrocenyl of the elements chromium, molybdenum and tungsten was carried out. The Fisher's compounds that were synthesized included the following combinations of two different metallic atoms: iron with chromium, iron with molybdenum and iron with tungsten. The molecular solids' preparation was done in electro-synthesis cells with platinum electrodes. Thin films were prepared by vacuum thermal evaporation on quartz substrates and crystalline silicon wafers. Pellets and thin films from these compounds were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, atomic force microscopy and ellipsometry. The powder and thin films synthesized from these materials show the same intra-molecular bonds shown by infrared spectroscopy results, suggesting that thermal evaporation does not alter these bonds in spite of the thin films being amorphous, in contrast with other bimetallic complexes where material decomposition occurs. The differences in the conductivity values of the prepared films are very small, so they may be attributed to the different metallic ions employed in each case. The tungsten complex exhibits a higher conductivity than the molybdenum and chromium complexes at room temperature. Electrical conductivity values found for thin films are higher than for pellets made of the same molecular materials

  3. Molecular beam epitaxy growth of InSb1−xBix thin films

    DEFF Research Database (Denmark)

    Song, Yuxin; Wang, Shumin; Saha Roy, Ivy

    2013-01-01

    Molecular beam epitaxy growth for InSb1−xBix thin films on (100) GaAs substrates is reported. Successful Bi incorporation for 2% is achieved, and up to 70% of the incorporated Bi atoms are at substitutional sites. The effects of growth parameters on Bi incorporation and surface morphology are stu...

  4. Growth of conductive HfO{sub 2-x} thin films by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institut fuer Materialwissenschaft, TU Darmstadt (Germany); Kleebe, Hans-Joachim [Institut fuer Angewandte Geowissenschaften, TU Darmstadt (Germany)

    2009-07-01

    Thin films of oxygen deficient hafnium oxide were grown on single crystal c-cut and r-cut sapphire substrates by reactive molecular beam epitaxy. The oxidation conditions during growth were varied within a wide range using RF-activated oxygen. Hafnium oxide thin films were characterized using X-ray diffraction, resistivity measurements ({rho}-T) and transmission electron microscopy (TEM). The results show a dramatic increase in conductivity of the deposited oxygen deficient hafnium oxide thin films with decreasing oxidation conditions during growth. The electrical properties of deficient hafnium oxide thin films varied from insulating over semiconducting to conducting. X-ray diffraction data as well as TEM data rule out the possibility of conductivity due to metallic hafnium.

  5. Optical observations of molecular dissociation in thin foils

    International Nuclear Information System (INIS)

    Berry, H.G.; Gay, T.J.; Brooks, R.L.

    1981-01-01

    We have measured the intensity and polarizations of light emitted from atomic excited states of dissociated molecular ions. Using HeH + projectiles, we have observed factors of 1-5 enhancements of the light from n=3, sup(1,3)P,D states of He I and some He II and H I emissions. Observations of Lyman alpha emission after dissociation of H 2 + and H 3 + show rapid variations in light yield for small internuclear separations at the foil surface. (author)

  6. Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

    Science.gov (United States)

    Li, Y.; Li, P.; Lu, Z.-H.

    2018-03-01

    A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS) investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

  7. Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

    Directory of Open Access Journals (Sweden)

    Y. Li

    2018-03-01

    Full Text Available A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS and x-ray photoelectron spectroscopy (XPS investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

  8. How to Measure Squeeze Out

    Energy Technology Data Exchange (ETDEWEB)

    Longacre, R. S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Physics Dept.

    2016-09-01

    Squeeze out happen when the expanding central fireball flows around a large surface flux tube in a central Au-Au collision at RHIC. We model such an effect in a flux tube model. Two particle correlations with respect to the v2 axis formed by the soft fireball particles flowing around this large flux tube is a way of measuring the effect.

  9. Growth of HfO{sub x} thin films by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institut fuer Materialwissenschaft, TU Darmstadt (Germany)

    2008-07-01

    Thin films of hafnium oxide were grown on single crystal r-cut and c-cut sapphire by reactive molecular beam epitaxy. The conditions for the growth of single oriented hafnium oxide thin films have been established. Hafnium oxide thin films were characterized by X-ray diffraction and optical absorption measurements. It was found that hafnium oxide thin films grown on r-cut sapphire were (00l) oriented whereas, on c-cut sapphire, hafnium oxide films showed different orientations depending on the growth temperature and oxidation conditions. The hafnium oxide films grown at higher temperature and under strong oxidation conditions yielded (001) oriented films on c-cut sapphire whereas slightly weaker oxidation condition leads to (111) oriented hafnium oxide films. The bandgap deducted from optical absorption measurement carried out on hafnium oxide films grown under optimized conditions agreed well with the values reported in literature. A range of oxygen deficient thin films of hafnium oxide were also grown on single crystal sapphire substrates in order to investigate the effect of oxygen vacancies on dielectric properties of hafnium oxide. The oxygen deficient thin films of hafnium oxide show a decrease in bandgap with increase in oxygen deficiency.

  10. Histological Stratification of Thick and Thin Plaque Psoriasis Explores Molecular Phenotypes with Clinical Implications

    Science.gov (United States)

    Kim, Dong Joo; Brodmerkel, Carrie; Correa da Rosa, Joel; Krueger, James G.; Suárez-Fariñas, Mayte

    2015-01-01

    Psoriasis, which presents as red, scaly patches on the body, is a common, autoimmune skin disease that affects 2 to 3 percent of the world population. To leverage recent molecular findings into the personalized treatment of psoriasis, we need a strategy that integrates clinical stratification with molecular phenotyping. In this study, we sought to stratify psoriasis patients by histological measurements of epidermal thickness, and to compare their molecular characterizations by gene expression, serum cytokines, and response to biologics. We obtained histological measures of epidermal thickness in a cohort of 609 psoriasis patients, and identified a mixture of two subpopulations—thick and thin plaque psoriasis—from which they were derived. This stratification was verified in a subcohort of 65 patients from a previously published study with significant differences in inflammatory cell infiltrates in the psoriatic skin. Thick and thin plaque psoriasis shared 84.8% of the meta-analysis-derived psoriasis transcriptome, but a stronger dysregulation of the meta-analysis-derived psoriasis transcriptome was seen in thick plaque psoriasis on microarray. RT-PCR revealed that gene expression in thick and thin plaque psoriasis was different not only within psoriatic lesional skin but also in peripheral non-lesional skin. Additionally, differences in circulating cytokines and their changes in response to biologic treatments were found between the two subgroups. All together, we were able to integrate histological stratification with molecular phenotyping as a way of exploring clinical phenotypes with different expression levels of the psoriasis transcriptome and circulating cytokines. PMID:26176783

  11. Short-cavity squeezing in barium

    Science.gov (United States)

    Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

    1992-01-01

    Broadband phase sensitive noise and squeezing were experimentally observed in a system of barium atoms interacting with a single mode of a short optical cavity. Squeezing of 13 +/- 3 percent was observed. A maximum possible squeezing of 45 +/- 8 percent could be inferred for out experimental conditions, after correction for measured loss factors. Noise reductions below the quantum limit were found over a range of detection frequencies 60-170 MHz and were best for high cavity transmission and large optical depths. The amount of squeezing observed is consistent with theoretical predictions from a full quantum statistical model of the system.

  12. YCo5±x thin films with perpendicular anisotropy grown by molecular beam epitaxy

    Science.gov (United States)

    Sharma, S.; Hildebrandt, E.; Sharath, S. U.; Radulov, I.; Alff, L.

    2017-06-01

    The synthesis conditions of buffer-free (00l) oriented YCo5 and Y2Co17 thin films onto Al2O3 (0001) substrates have been explored by molecular beam epitaxy (MBE). The manipulation of the ratio of individual atomic beams of Yttrium, Y and Cobalt, Co, as well as growth rate variations allows establishing a thin film phase diagram. Highly textured YCo5±x thin films were stabilized with saturation magnetization of 517 emu/cm3 (0.517 MA/m), coercivity of 4 kOe (0.4 T), and anisotropy constant, K1, equal to 5.34 ×106 erg/cm3 (0.53 MJ/m3). These magnetic parameters and the perpendicular anisotropy obtained without additional underlayers make the material system interesting for application in magnetic recording devices.

  13. Thin film phase diagram of iron nitrides grown by molecular beam epitaxy

    Science.gov (United States)

    Gölden, D.; Hildebrandt, E.; Alff, L.

    2017-01-01

    A low-temperature thin film phase diagram of the iron nitride system is established for the case of thin films grown by molecular beam epitaxy and nitrided by a nitrogen radical source. A fine-tuning of the nitridation conditions allows for growth of α ‧ -Fe8Nx with increasing c / a -ratio and magnetic anisotropy with increasing x until almost phase pure α ‧ -Fe8N1 thin films are obtained. A further increase of nitrogen content below the phase decomposition temperature of α ‧ -Fe8N (180 °C) leads to a mixture of several phases that is also affected by the choice of substrate material and symmetry. At higher temperatures (350 °C), phase pure γ ‧ -Fe4N is the most stable phase.

  14. High quality atomically thin PtSe2 films grown by molecular beam epitaxy

    Science.gov (United States)

    Yan, Mingzhe; Wang, Eryin; Zhou, Xue; Zhang, Guangqi; Zhang, Hongyun; Zhang, Kenan; Yao, Wei; Lu, Nianpeng; Yang, Shuzhen; Wu, Shilong; Yoshikawa, Tomoki; Miyamoto, Koji; Okuda, Taichi; Wu, Yang; Yu, Pu; Duan, Wenhui; Zhou, Shuyun

    2017-12-01

    Atomically thin PtSe2 films have attracted extensive research interests for potential applications in high-speed electronics, spintronics and photodetectors. Obtaining high quality thin films with large size and controlled thickness is critical. Here we report the first successful epitaxial growth of high quality PtSe2 films by molecular beam epitaxy. Atomically thin films from 1 ML to 22 ML have been grown and characterized by low-energy electron diffraction, Raman spectroscopy and x-ray photoemission spectroscopy. Moreover, a systematic thickness dependent study of the electronic structure is revealed by angle-resolved photoemission spectroscopy (ARPES), and helical spin texture is revealed by spin-ARPES. Our work provides new opportunities for growing large size single crystalline films to investigate the physical properties and potential applications of PtSe2.

  15. Recognition of conformational changes in beta-lactoglobulin by molecularly imprinted thin films.

    Science.gov (United States)

    Turner, Nicholas W; Liu, Xiao; Piletsky, Sergey A; Hlady, Vladimir; Britt, David W

    2007-09-01

    Pathogenesis in protein conformational diseases is initiated by changes in protein secondary structure. This molecular restructuring presents an opportunity for novel shape-based detection approaches, as protein molecular weight and chemistry are otherwise unaltered. Here we apply molecular imprinting to discriminate between distinct conformations of the model protein beta-lactoglobulin (BLG). Thermal- and fluoro-alcohol-induced BLG isoforms were imprinted in thin films of 3-aminophenylboronic acid on quartz crystal microbalance chips. Enhanced rebinding of the template isoform was observed in all cases when compared to the binding of nontemplate isoforms over the concentration range of 1-100 microg mL(-1). Furthermore, it was observed that the greater the changes in the secondary structure of the template protein the lower the binding of native BLG challenges to the imprint, suggesting a strong steric influence in the recognition system. This feasibility study is a first demonstration of molecular imprints for recognition of distinct conformations of the same protein.

  16. Growth of thin films of low molecular weight proteins by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Matei, Andreea; Schou, Jørgen; Constantinescu, C.

    2011-01-01

    Thin films of lysozyme and myoglobin grown by matrix assisted pulsed laser evaporation (MAPLE) from a water ice matrix have been investigated. The deposition rate of these two low molecular weight proteins (lysozyme: 14307 amu and myoglobin: 17083 amu) exhibits a maximum of about 1–2 ng/cm2 per....... The results for lysozyme demonstrate that the fragmentation rate of the proteins during the MAPLE process is not influenced by the pH of the water solution prior to freezing....

  17. An Experimental and numerical Study for squeezing flow

    Science.gov (United States)

    Nathan, Rungun; Lang, Ji; Wu, Qianhong; Vucbmss Team

    2017-11-01

    We report an experimental and numerical study to examine the transient squeezing flow driven by sudden external impacts. The phenomenon is widely observed in industrial applications, e.g. squeeze dampers, or in biological systems, i.e. joints lubrication. However, there is a lack of investigation that captures the transient flow feature during the process. An experimental setup was developed that contains a piston instrumented with a laser displacement sensor and a pressure transducer. The heavy piston was released from rest, creating a fast compaction on the thin fluid gap underneath. The motion of the piston and the fluid pressure build-up was recorded. For this dynamic process, a CFD simulation was performed which shows excellent agreement with the experimental data. Both the numerical and experimental results show that, the squeezing flow starts with the inviscid limit when the viscous fluid effect has no time to appear, and thereafter becomes a developing flow, in which the inviscid core flow region decreases and the viscous wall region increases until the entire fluid gap is filled with viscous fluid flow. The study presented herein, filling the gap in the literature, will have broad impacts in industrial and biomedical applications. This research was supported by the National Science Foundation under Award 1511096, and supported by the Seed Grant from The Villanova Center for the Advancement of Sustainability in Engineering (VCASE).

  18. The dependence of fidelity on the squeezing parameter in teleportation of the squeezed coherent states

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing-Tao; He Guang-Qiang; Ren Li-Jie; Zeng Gui-Hua

    2011-01-01

    This paper investigates an analytical expression of teleportation fidelity in the teleportation scheme of a single mode of electromagnetic field. The fidelity between the original squeezed coherent state and the teleported one is expressed in terms of the squeezing parameter r and the quantum channel parameter (two-mode squeezed state) p. The results of analysis show that the fidelity increases with the increase of the quantum channel parameter p, while the fidelity decreases with the increase of the squeezing parameter r of the squeezed state. Thus the coherent state (r = 0)is the best quantum signal for continuous variable quantum teleportation once the quantum channel is built.

  19. Pulsed Traveling-wave Quadrature Squeezing Using Quasi-phase Matched Lithium Niobate Crystals

    Science.gov (United States)

    Chen, Chao-Hsiang

    Interests in generating higher quantum noise squeezing in order to develop methods to enhance optical measurement below the shot-noise limit in various applications has grown in recent years. The noise suppression from squeezing can improve the SNR in coherent optical systems when the returning signal power is weak, such as optical coherence tomography, LADAR, confocal microscopy and low-light coherent imaging. Unlike the generation of squeezing with a continuous wave, which is currently developed mainly for gravitational wave detection in LIGO project, the study of pulsed-traveling waves is focused on industrial, medical and other commercial interests. This dissertation presents the experimental results of pulsed traveling wave squeezing. The intention of the study is to explore the possibility of using quasi-phase matched crystals to generate the highest possible degree of quadrature squeezing. In order to achieve this goal, efforts to test the various effects from spatial Gaussian modes and relative beam waist placement for the second-harmonic pump were carried out in order to further the understanding of limiting factors to pulsed traveling wave squeezing. 20mm and 30mm-long periodically poled lithium noibate (PPLN) crystals were used in the experiment to generate a squeezed vacuum state. A maximum of 4.2+/-0.2dB quadrature squeezing has been observed, and the measured anti-squeezing exceeds 20dB.The phase sensitive amplification (PSA) gain and de-gain performance were also measured to compare the results of measured squeezing. The PPLN crystals can produce high conversion efficiency of second-harmonic generation (SHG) without a cavity. When a long PPLN crystal is used in a squeezer, the beam propagation in the nonlinear medium does not follow the characteristics in thin crystals. Instead, it is operated under the long-crystal criteria, which the crystal length is multiple times longer than the Rayleigh range of the injected beam i n the crystals. Quasi

  20. Teleportation of Squeezed Entangled State

    Institute of Scientific and Technical Information of China (English)

    HU Li-Yun; ZHOU Nan-Run

    2007-01-01

    Based on the coherent entangled state |α, x> we introduce the squeezed entangled state (SES). Then we propose a teleportation protocol for the SES by using Einstein-Podolsky-Rosen entangled state |η>as a quantum channel.The calculation is greatly simplified by virtue of the Schmidt decompositions of both |α, x>and |η>. Any bipartite states that can be expanded in terms of |α, x>may be teleported in this way due to the completeness of |α, x>.

  1. Parsing polarization squeezing into Fock layers

    DEFF Research Database (Denmark)

    Mueller, Christian R.; Madsen, Lars Skovgaard; Klimov, Andrei B.

    2016-01-01

    photon number do the methods coincide; when the photon number is indefinite, we parse the state in Fock layers, finding that substantially higher squeezing can be observed in some of the single layers. By capitalizing on the properties of the Husimi Q function, we map this notion onto the Poincare space......, providing a full account of the measured squeezing....

  2. Workshop on Squeezed States and Uncertainty Relations

    International Nuclear Information System (INIS)

    Han, D.; Kim, Y.S.; Zachary, W.W.

    1992-02-01

    The proceedings from the workshop are presented, and the focus was on the application of squeezed states. There are many who say that the potential for industrial applications is enormous, as the history of the conventional laser suggests. All those who worked so hard to produce squeezed states of light are continuing their efforts to construct more efficient squeezed-state lasers. Quite naturally, they are looking for new experiments using these lasers. The physical basis of squeezed states is the uncertainty relation in Fock space, which is also the basis for the creation and annihilation of particles in quantum field theory. Indeed, squeezed states provide a unique opportunity for field theoreticians to develop a measurement theory for quantum field theory

  3. Molecularly thin fluoro-polymeric nanolubricant films: tribology, rheology, morphology, and applications.

    Science.gov (United States)

    Chung, Pil Seung; Jhon, Myung S; Choi, Hyoung Jin

    2016-03-21

    Molecularly thin perfluoropolyether (PFPE) has been used extensively as a high-performance lubricant in various applications and, more importantly, on carbon overcoats to enhance the reliability and lubrication of micro-/nanoelectro-mechanical systems, where the tribological performance caused by its molecular architecture is a critical issue, as are its physical properties and rheological characteristics. This Highlight addresses recent trends in the development of fluoro-polymeric lubricant films with regard to their tribology, rheology, and physio-chemical properties as they relate to heat-assisted magnetic recording. Nanorheology has been employed to examine the dynamic response of nonfunctional and functional PFPEs, while the viscoelastic properties of nanoscale PFPE films and the relaxation processes as a function of molecular structure and end-group functionality were analyzed experimentally; furthermore, the characteristics of binary blends were reported.

  4. Molecularly ordered aluminum tris-(8-hydroxyquinoline) thin films grown by hot-wall deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tapponnier, A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)]. E-mail: axelle@phys.ethz.ch; Khan, R.U.A. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland); Marcolli, C. [Institute of Atmospheric and Climate Sciences, Swiss Federal Institute of Technology Zuerich (ETH), CH-8092 Zurich (Switzerland); Guenter, P. [Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology Zuerich (ETH), CH-8093 Zurich (Switzerland)

    2007-01-22

    We report on the growth and microstructural analysis of molecularly ordered thin film layers of aluminum tris-(8-hydroxyquinoline) (Alq{sub 3}) by hot-wall deposition onto amorphous glass substrates. Using transmission electron microscopy (TEM), ordering on a scale of 100 nm was observed. Raman measurements of these films indicated that they corresponded to the {alpha}-polymorph of crystalline Alq{sub 3}, and photoluminescence measurements exhibited a single broad peak centered at 500 nm, which is also consistent with the {alpha}-form. As a comparison, we deposited films of Alq3 using organic molecular beam deposition (OMBD), which exhibited no molecular ordering from the TEM studies. For these films, strong point-to-point variations in the Raman spectrum, and the existence of a double peak in the photoluminescence at 500 and 522 nm were observed. These measurements indicate that the OMBD films possess a mixture of both {alpha} and amorphous phases.

  5. The effects of polymer molecular weight on filament thinning and drop breakup in microchannels

    International Nuclear Information System (INIS)

    Arratia, P E; Cramer, L-A; Gollub, J P; Durian, D J

    2009-01-01

    We investigate the effects of fluid elasticity on the dynamics of filament thinning and drop breakup processes in a cross-slot microchannel. Elasticity effects are examined using dilute aqueous polymeric solutions of molecular weight (MW) ranging from 1.5x10 3 to 1.8x10 7 . Results for polymeric fluids are compared to those for a viscous Newtonian fluid. The shearing or continuous phase that induces breakup is mineral oil. All fluids possess similar shear-viscosity (∼0.2 Pa s) so that the viscosity ratio between the oil and aqueous phases is close to unity. Measurements of filament thickness as a function of time show different thinning behavior for the different aqueous fluids. For Newtonian fluids, the thinning process shows a single exponential decay of the filament thickness. For low MW fluids (10 3 , 10 4 and 10 5 ), the thinning process also shows a single exponential decay, but with a decay rate that is slower than for the Newtonian fluid. The decay time increases with polymer MW. For high MW (10 6 and 10 7 ) fluids, the initial exponential decay crosses over to a second exponential decay in which elastic stresses are important. We show that the decay rate of the filament thickness in this exponential decay regime can be used to measure the steady extensional viscosity of the fluids. At late times, all fluids cross over to an algebraic decay which is driven mainly by surface tension.

  6. Thermoelectric Properties of Nanograined Si-Ge-Au Thin Films Grown by Molecular Beam Deposition

    Science.gov (United States)

    Nishino, Shunsuke; Ekino, Satoshi; Inukai, Manabu; Omprakash, Muthusamy; Adachi, Masahiro; Kiyama, Makoto; Yamamoto, Yoshiyuki; Takeuchi, Tsunehiro

    2018-06-01

    Conditions to achieve extremely large Seebeck coefficient and extremely small thermal conductivity in Si-Ge-Au thin films formed of nanosized grains precipitated in amorphous matrix have been investigated. We employed molecular beam deposition to prepare Si1- x Ge x Au y thin films on sapphire substrate. The deposited films were annealed under nitrogen gas atmosphere at 300°C to 500°C for 15 min to 30 min. Nanocrystals dispersed in amorphous matrix were clearly observed by transmission electron microscopy. We did not observe anomalously large Seebeck coefficient, but very low thermal conductivity of nearly 1.0 W K-1 m-1 was found at around 0.2 Si-Ge bulk material for which dimensionless figure of merit of ZT ≈ 1 was reported at high temperature.

  7. Molecular-Beam Epitaxially Grown MgB2 Thin Films and Superconducting Tunnel Junctions

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Laloë

    2011-01-01

    Full Text Available Since the discovery of its superconducting properties in 2001, magnesium diboride has generated terrific scientific and engineering research interest around the world. With a of 39 K and two superconducting gaps, MgB2 has great promise from the fundamental point of view, as well as immediate applications. Several techniques for thin film deposition and heterojunction formation have been established, each with its own advantages and drawbacks. Here, we will present a brief overview of research based on MgB2 thin films grown by molecular beam epitaxy coevaporation of Mg and B. The films are smooth and highly crystalline, and the technique allows for virtually any heterostructure to be formed, including all-MgB2 tunnel junctions. Such devices have been characterized, with both quasiparticle and Josephson tunneling reported. MgB2 remains a material of great potential for a multitude of further characterization and exploration research projects and applications.

  8. Self-regulated growth of LaVO3 thin films by hybrid molecular beam epitaxy

    International Nuclear Information System (INIS)

    Zhang, Hai-Tian; Engel-Herbert, Roman; Dedon, Liv R.; Martin, Lane W.

    2015-01-01

    LaVO 3 thin films were grown on SrTiO 3 (001) by hybrid molecular beam epitaxy. A volatile metalorganic precursor, vanadium oxytriisopropoxide (VTIP), and elemental La were co-supplied in the presence of a molecular oxygen flux. By keeping the La flux fixed and varying the VTIP flux, stoichiometric LaVO 3 films were obtained for a range of cation flux ratios, indicating the presence of a self-regulated growth window. Films grown under stoichiometric conditions were found to have the largest lattice parameter, which decreased monotonically with increasing amounts of excess La or V. Energy dispersive X-ray spectroscopy and Rutherford backscattering measurements were carried out to confirm film compositions. Stoichiometric growth of complex vanadate thin films independent of cation flux ratios expands upon the previously reported self-regulated growth of perovskite titanates using hybrid molecular beam epitaxy, thus demonstrating the general applicability of this growth approach to other complex oxide materials, where a precise control over film stoichiometry is demanded by the application

  9. The spectral analysis of an aero-engine assembly incorporating a squeeze-film damper

    Science.gov (United States)

    Holmes, R.; Dede, M. M.

    1989-01-01

    Aero-engine structures have very low inherent damping and so artificial damping is often introduced by pumping oil into annular gaps between the casings and the outer races of some or all of the rolling-element bearings supporting the rotors. The thin oil films so formed are called squeeze film dampers and they can be beneficial in reducing rotor vibration due to unbalance and keeping to reasonable limits the forces transmitted to the engine casing. However, squeeze-film dampers are notoriously non-linear and as a result can introduce into the assembly such phenomena as subharmonic oscillations, jumps and combination frequencies. The purpose of the research is to investigate such phenomena both theoretically and experimentally on a test facility reproducing the essential features of a medium-size aero engine. The forerunner of this work was published. It was concerned with the examination of a squeeze-film damper in series with housing flexibility when supporting a rotor. The structure represented to a limited extent the essentials of the projected Rolls Royce RB401 engine. That research demonstrated the ability to calculate the oil-film forces arising from the squeeze film from known motions of the bearing components and showed that the dynamics of a shaft fitted with a squeeze film bearing can be predicted reasonably accurately. An aero-engine will normally have at least two shafts and so in addition to the excitation forces which are synchronous with the rotation of one shaft, there will also be forces at other frequencies from other shafts operating on the squeeze-film damper. Theoretical and experimental work to consider severe loading of squeeze-film dampers and to include these additional effects are examined.

  10. A Brief Discussion Regarding Types of Cavitation in Squeeze Film Dampers and Cavitation Effects

    Directory of Open Access Journals (Sweden)

    Laurentiu MORARU

    2017-03-01

    Full Text Available Squeeze film dampers (SFD are probably the most used shaft control devices in aircraft jet engines; SFDs consist in oil films, elastic elements and various antirotational devices that tune the stiffness and damping of the shafts’ supports and consequently adjust the lateral dynamics of the shaft. Fluid layers in SFDs are usually thin, hence the modeling can often be done using the Reynolds’ theory,; however, some of the main features of the film, namely the behavior of the fluid in the divergent, negative squeeze area, where discontinuities may appear in the liquid, are still subject to intense research. This paper will discuss some aspects regarding the types of cavitation that appear in squeeze film dampers and some of the effects of cavitation on the SFDs.

  11. Coherent and squeezed states in phase space

    International Nuclear Information System (INIS)

    Jannussis, A.; Bartzis, V.; Vlahos, E.

    1990-01-01

    In the present paper, the coherent and the squeezed states in phase space have been studied. From the wave functions of the coherent and the squeezed state, their corresponding Wigner distribution functions are calculated. Especially the calculation of the corresponding Wigner functions for the above states permits the determination of the mean values of position and momentum and thus the Heisenberg uncertainty relation. In fact, from the related results, it is concluded that the uncertainty relation of the coherent and associated squeezed states is the same

  12. Magnetically engineered smart thin films: toward lab-on-chip ultra-sensitive molecular imaging.

    Science.gov (United States)

    Hassan, Muhammad A; Saqib, Mudassara; Shaikh, Haseeb; Ahmad, Nasir M; Elaissari, Abdelhamid

    2013-03-01

    Magnetically responsive engineered smart thin films of nanoferrites as contrast agent are employed to develop surface based magnetic resonance imaging to acquire simple yet fast molecular imaging. The work presented here can be of significant potential for future lab-on-chip point-of-care diagnostics from the whole blood pool on almost any substrates to reduce or even prevent clinical studies involve a living organism to enhance the non-invasive imaging to advance the '3Rs' of work in animals-replacement, refinement and reduction.

  13. Molecular Weight Effects on the Glass Transition and Confinement Behavior of Polymer Thin Films.

    Science.gov (United States)

    Xia, Wenjie; Hsu, David D; Keten, Sinan

    2015-08-01

    Nanoscale polymer thin films exhibit strong confinement effects on Tg arising from free surfaces. However, the coupled influence of molecular weight (MW) and surface effects on Tg is not well understood for low MW film systems below the entanglement length. Utilizing atomistically informed coarse-grained molecular dynamics simulations for poly(methyl methacrylate) (PMMA), it is demonstrated that the decrease in free-standing film Tg with respect to bulk is more significant for low MW compared to high MW systems. Investigation of the local interfacial properties reveals that the increase in the local free volume near the free surface is greater for low MW, explaining the MW dependence of Tg -confinement behaviors. These findings corroborate recent experiments on low MW films, and highlight the relationship between nanoconfinement phenomena and local free volume effects arising from free surfaces. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Mesoporous thin films of ``molecular squares'' as sensors for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Keefe, M.H.; Slone, R.V.; Hupp, J.T.; Czaplewski, K.F.; Snurr, R.Q.; Stern, C.L.

    2000-04-18

    Mesoporous thin films of rhenium-based molecular squares, [Re(CO){sub 3}Cl(L)]{sub 4} (L = pyrazine, 4,4{prime}-bipyridine), have been utilized as sensors for volatile organic compounds (VOCs). The sensing was conducted using a quartz crystal microbalance with the target compounds present in the gas phase at concentrations ranging from 0.05 to 1 mM. Quartz crystal microbalance studies with these materials allowed for distinction between the following VOCs: (1) small aromatic versus aliphatic molecules of almost identical size and volatility and (2) an array of benzene molecules derivatized with electron donating/withdrawing substituents. The experiments suggest that the mesoporous host materials interact with VOC guest molecules through both van der Waals and weak charge-transfer interactions. In addition, size selectivity is shown by exposure of the molecular squares to cyclic ethers of differing size.

  15. Molecular and electronic structure of thin films of protoporphyrin(IX)Fe(III)Cl

    Science.gov (United States)

    Snyder, Shelly R.; White, Henry S.

    1991-11-01

    Electrochemical, scanning tunneling microscopy (STM), and tunneling spectroscopy studies of the molecular and electronic properties of thin films of protoporphyrin(IX)Fe(III)Cl (abbreviated as PP(IX)Fe(III)Cl) on highly oriented pyrolytic graphite (HOPG) electrodes are reported. PP(IX)Fe(III)Cl films are prepared by two different methods: (1) adsorption, yielding an electrochemically-active film, and (2) irreversible electrooxidative polymerization, yielding an electrochemically-inactive film. STM images, in conjunction with electro-chemical results, indicate that adsorption of PP(IX)Fe(III)Cl from aqueous solutions onto freshly cleaved HOPG results in a film comprised of molecular aggregates. In contrast, films prepared by irreversible electrooxidative polymerization of PP(IX)Fe(III)Cl have a denser, highly structured morphology, including what appear to be small pinholes (approx. 50A diameter) in an otherwise continuous film.

  16. Simulation of the molecular recombination yield for swift H2+ ions through thin carbon foils

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Barriga-Carrasco, Manuel D.

    2003-01-01

    We have calculated the recombination yield for swift H 2 + molecular ions at the exit of thin amorphous carbon foils, as a function of the dwell time and incident energy. Our results are based on a detailed simulation of the motion through the target of the H 2 + molecular ion (before dissociation takes place) and its constituent fragments (after dissociation), including the following effects: Coulomb repulsion, nuclear scattering, electron capture and loss, as well as self-retarding and wake forces, which provide the relative distance and velocity of the dissociated fragments at the foil exit. The recombination of an H 2 + ion at the exit of the foil depends on the interproton separation and internal energy of the dissociated fragments, and on their probability to capture an electron. Comparison of our results with the available experimental data shows a good agreement

  17. Molecular doping for control of gate bias stress in organic thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Hein, Moritz P., E-mail: hein@iapp.de; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Zakhidov, Alexander A. [Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany); Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany); Fraunhofer COMEDD, Maria-Reiche-Str. 2, 01109 Dresden (Germany)

    2014-01-06

    The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface.

  18. Molecular doping for control of gate bias stress in organic thin film transistors

    International Nuclear Information System (INIS)

    Hein, Moritz P.; Lüssem, Björn; Jankowski, Jens; Tietze, Max L.; Riede, Moritz K.; Zakhidov, Alexander A.; Leo, Karl

    2014-01-01

    The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface

  19. Sputter-deposited Mg-Al-O thin films: linking molecular dynamics simulations to experiments

    International Nuclear Information System (INIS)

    Georgieva, V; Bogaerts, A; Saraiva, M; Depla, D; Jehanathan, N; Lebelev, O I

    2009-01-01

    Using a molecular dynamics model the crystallinity of Mg x Al y O z thin films with a variation in the stoichiometry of the thin film is studied at operating conditions similar to the experimental operating conditions of a dual magnetron sputter deposition system. The films are deposited on a crystalline or amorphous substrate. The Mg metal content in the film ranged from 100% (i.e. MgO film) to 0% (i.e. Al 2 O 3 film). The radial distribution function and density of the films are calculated. The results are compared with x-ray diffraction and transmission electron microscopy analyses of experimentally deposited thin films by the dual magnetron reactive sputtering process. Both simulation and experimental results show that the structure of the Mg-Al-O film varies from crystalline to amorphous when the Mg concentration decreases. It seems that the crystalline Mg-Al-O films have a MgO structure with Al atoms in between.

  20. Quantum nondemolition squeezing of a nanomechanical resonator

    Science.gov (United States)

    Ruskov, Rusko; Schwab, Keith; Korotkov, Alexander

    2005-03-01

    We discuss squeezing of the nanoresonator state produced by periodic measurement of position by a quantum point contact or a single-electron transistor. The mechanism of squeezing is the stroboscopic quantum nondemolition measurement generalized to the case of continuous measurement by a weakly coupled detector. The magnitude of squeezing is calculated for the harmonic and stroboscopic modulations of measurement, taking into account detector efficiency and nanoresonator quality factor. We also analyze the operation of the quantum feedback, which prevents fluctuations of the wavepacket center due to measurement back-action. Verification of the squeezed state can be performed in almost the same way as its preparation; similar procedure can also be used for the force detection with sensitivity beyond the standard quantum limit.

  1. Magnon squeezing states in a ferromagnet

    International Nuclear Information System (INIS)

    Wang Junfeng; Cheng Ze; Ping Yunxia; Wan Jinyin; Zhang Yanmin

    2006-01-01

    In this Letter we discuss squeezing state of magnon in ferromagnet, which permits a reduction in the quantum fluctuation of the spin component to below the zero-point quantum noise level of coherent magnon states. We investigate the generation of squeezed magnon state through calculating the expectation values of spin component fluctuation. The mean field theory is introduced in dealing with the nonlinear interaction terms of Hamiltonian of magnon system

  2. Exploiting Molecular Weight Distribution Shape to Tune Domain Spacing in Block Copolymer Thin Films.

    Science.gov (United States)

    Gentekos, Dillon T; Jia, Junteng; Tirado, Erika S; Barteau, Katherine P; Smilgies, Detlef-M; DiStasio, Robert A; Fors, Brett P

    2018-04-04

    We report a method for tuning the domain spacing ( D sp ) of self-assembled block copolymer thin films of poly(styrene- block-methyl methacrylate) (PS- b-PMMA) over a large range of lamellar periods. By modifying the molecular weight distribution (MWD) shape (including both the breadth and skew) of the PS block via temporal control of polymer chain initiation in anionic polymerization, we observe increases of up to 41% in D sp for polymers with the same overall molecular weight ( M n ≈ 125 kg mol -1 ) without significantly changing the overall morphology or chemical composition of the final material. In conjunction with our experimental efforts, we have utilized concepts from population statistics and least-squares analysis to develop a model for predicting D sp based on the first three moments of the MWDs. This statistical model reproduces experimental D sp values with high fidelity (with mean absolute errors of 1.2 nm or 1.8%) and provides novel physical insight into the individual and collective roles played by the MWD moments in determining this property of interest. This work demonstrates that both MWD breadth and skew have a profound influence over D sp , thereby providing an experimental and conceptual platform for exploiting MWD shape as a simple and modular handle for fine-tuning D sp in block copolymer thin films.

  3. Recognition of Conformational Changes in β-Lactoglobulin by Molecularly Imprinted Thin Films

    Science.gov (United States)

    Turner, Nicholas W.; Liu, Xiao; Piletsky, Sergey A.; Hlady, Vladimir; Britt, David W.

    2008-01-01

    Pathogenesis in protein conformational diseases is initiated by changes in protein secondary structure. This molecular restructuring presents an opportunity for novel shape-based detection approaches, as protein molecular weight and chemistry are otherwise unaltered. Here we apply molecular imprinting to discriminate between distinct conformations of the model protein β-lactoglobulin (BLG). Thermal- and fluoro-alcohol-induced BLG isoforms were imprinted in thin films of 3-aminophenylboronic acid on quartz crystal microbalance chips. Enhanced rebinding of the template isoform was observed in all cases when compared to the binding of nontemplate isoforms over the concentration range of 1–100 µg mL−1. Furthermore, it was observed that the greater the changes in the secondary structure of the template protein the lower the binding of native BLG challenges to the imprint, suggesting a strong steric influence in the recognition system. This feasibility study is a first demonstration of molecular imprints for recognition of distinct conformations of the same protein. PMID:17665947

  4. Waveguide quantum electrodynamics in squeezed vacuum

    Science.gov (United States)

    You, Jieyu; Liao, Zeyang; Li, Sheng-Wen; Zubairy, M. Suhail

    2018-02-01

    We study the dynamics of a general multiemitter system coupled to the squeezed vacuum reservoir and derive a master equation for this system based on the Weisskopf-Wigner approximation. In this theory, we include the effect of positions of the squeezing sources which is usually neglected in the previous studies. We apply this theory to a quasi-one-dimensional waveguide case where the squeezing in one dimension is experimentally achievable. We show that while dipole-dipole interaction induced by ordinary vacuum depends on the emitter separation, the two-photon process due to the squeezed vacuum depends on the positions of the emitters with respect to the squeezing sources. The dephasing rate, decay rate, and the resonance fluorescence of the waveguide-QED in the squeezed vacuum are controllable by changing the positions of emitters. Furthermore, we demonstrate that the stationary maximum entangled NOON state for identical emitters can be reached with arbitrary initial state when the center-of-mass position of the emitters satisfies certain conditions.

  5. Squeezed States in Josephson Junctions.

    Science.gov (United States)

    Hu, X.; Nori, F.

    1996-03-01

    We have studied quantum fluctuation properties of Josephson junctions in the limit of large Josephson coupling energy and small charging energy, when the eigenstates of the system can be treated as being nearly localized. We have considered(X. Hu and F. Nori, preprints.) a Josephson junction in a variety of situations, e.g., coupled to one or several of the following elements: a capacitor, an inductor (in a superconducting ring), and an applied current source. By solving an effective Shrödinger equation, we have obtained squeezed vacuum (coherent) states as the ground states of a ``free-oscillating'' (linearly-driven) Josephson junction, and calculated the uncertainties of its canonical momentum, charge, and coordinate, phase. We have also shown that the excited states of the various systems we consider are similar to the number states of a simple harmonic oscillator but with different fluctuation properties. Furthermore, we have obtained the time-evolution operators for these systems. These operators can make it easier to calculate the time-dependence of the expectation values and fluctuations of various quantities starting from an arbitrary initial state.

  6. LHC Report: Freshly squeezed beams!

    CERN Multimedia

    Mike Lamont for the LHC Team

    2011-01-01

    After careful validation of  new machine settings, the LHC was ready for higher luminosity operation. New luminosity records have been set, but the operations team continues to wrestle with machine availability issues.   The commissioning of the squeeze to a ß* of 1 m in ATLAS and CMS described in the last Bulletin took until Wednesday, 7 September to complete. In order to validate the new set-up, beam losses were provoked in a controlled way with low intensity beams. The distribution of beam loss around the machine in these tests is known as a loss map. The loss maps showed that the collimation system is catching the large majority of beam losses as it should, and that the machine was ready for us to ramp the number of bunches back up and go to physics production. The ramp-up of the number of bunches went smoothly with fills at 264, 480, and 912 bunches on the way back to the machine’s previous record of 1380 bunches (first fill on Friday, 9 Se...

  7. The Second International Workshop on Squeezed States and Uncertainty Relations

    Science.gov (United States)

    Han, D. (Editor); Kim, Y. S.; Manko, V. I.

    1993-01-01

    This conference publication contains the proceedings of the Second International Workshop on Squeezed States and Uncertainty Relations held in Moscow, Russia, on 25-29 May 1992. The purpose of this workshop was to study possible applications of squeezed states of light. The Workshop brought together many active researchers in squeezed states of light and those who may find the concept of squeezed states useful in their research, particularly in understanding the uncertainty relations. It was found at this workshop that the squeezed state has a much broader implication than the two-photon coherent states in quantum optics, since the squeeze transformation is one of the most fundamental transformations in physics.

  8. Effect of Surface Roughness on MHD Couple Stress Squeeze-Film Characteristics between a Sphere and a Porous Plane Surface

    Directory of Open Access Journals (Sweden)

    M. Rajashekar

    2012-01-01

    Full Text Available The combined effects of couple stress and surface roughness on the MHD squeeze-film lubrication between a sphere and a porous plane surface are analyzed, based upon the thin-film magnetohydrodynamic (MHD theory. Using Stoke’s theory to account for the couple stresses due to the microstructure additives and the Christensen’s stochastic method developed for hydrodynamic lubrication of rough surfaces derives the stochastic MHD Reynolds-type equation. The expressions for the mean MHD squeeze-film pressure, mean load-carrying capacity, and mean squeeze-film time are obtained. The results indicate that the couple stress fluid in the film region enhances the mean MHD squeeze-film pressure, load-carrying capacity, and squeeze-film time. The effect of roughness parameter is to increase (decrease the load-carrying capacity and lengthen the response time for azimuthal (radial roughness patterns as compared to the smooth case. Also, the effect of porous parameter is to decrease the load-carrying capacity and increase the squeeze-film time as compared to the solid case.

  9. Evaporation characteristics of thin film liquid argon in nano-scale confinement: A molecular dynamics study

    Science.gov (United States)

    Hasan, Mohammad Nasim; Shavik, Sheikh Mohammad; Rabbi, Kazi Fazle; Haque, Mominul

    2016-07-01

    Molecular dynamics simulation has been carried out to explore the evaporation characteristics of thin liquid argon film in nano-scale confinement. The present study has been conducted to realize the nano-scale physics of simultaneous evaporation and condensation inside a confined space for a three phase system with particular emphasis on the effect of surface wetting conditions. The simulation domain consisted of two parallel platinum plates; one at the top and another at the bottom. The fluid comprised of liquid argon film at the bottom plate and vapor argon in between liquid argon and upper plate of the domain. Considering hydrophilic and hydrophobic nature of top and bottom surfaces, two different cases have been investigated: (i) Case A: Both top and bottom surfaces are hydrophilic, (ii) Case B: both top and bottom surfaces are hydrophobic. For all cases, equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. Then the lower wall was set to four different temperatures such as 110 K, 120 K, 130 K and 140 K to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat fluxes normal to top and bottom walls were estimated and discussed to illuminate the effectiveness of heat transfer in both hydrophilic and hydrophobic confinement at various boundary temperatures of the bottom plate.

  10. CeCo5 thin films with perpendicular anisotropy grown by molecular beam epitaxy

    Science.gov (United States)

    Sharma, S.; Hildebrandt, E.; Major, M.; Komissinskiy, P.; Radulov, I.; Alff, L.

    2018-04-01

    Buffer-free, highly textured (0 0 1) oriented CeCo5 thin films showing perpendicular magnetic anisotropy were synthesized on (0 0 1) Al2O3 substrates by molecular beam epitaxy. Ce exists in a mixture of Ce3+ and Ce4+ valence states as shown by X-ray photoelectron spectroscopy. The first anisotropy constant, K1, as measured by torque magnetometry was 0.82 MJ/m3 (8.2 ×106erg /cm3) . A maximum coercivity of 5.16 kOe with a negative temperature coefficient of -0.304%K-1 and a magnetization of 527.30 emu/cm3 was measured perpendicular to the film plane at 5 K. In addition, a large anisotropy of the magnetic moment of 15.5% was observed. These magnetic parameters make CeCo5 a potential candidate material for spintronic and magnetic recording applications.

  11. Surface electronic structure and molecular orientation of poly(9-vinylcarbazole) thin film: ARUPS and NEXAFS

    CERN Document Server

    Okudaira, K K; Hasegawa, S; Ishii, H; Azuma, Y; Imamura, M; Shimada, H; Seki, K; Ueno, N

    2001-01-01

    The molecular orientation at the surfaces of poly(9-vinylcarbazole) (PvCz) thin films was studied by angle-resolved ultraviolet photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The observed take-off angle (theta) dependence of photoelectron intensities from top pi band peaks clearly at larger theta than the calculated one for the three-dimensional isotropic random orientation model. The results indicate that there are more pendant groups with large tilt angles than the three-dimensional isotropic random orientation model, which is in good agreement with the result obtained from NEXAFS spectroscopy. The surface electronic states of PvCz may be rather dominated by sigma(C-H) states at the pendant carbazole group than pi states

  12. High efficiency thin film solar cells grown by molecular beam epitaxy (HEFTY)

    Energy Technology Data Exchange (ETDEWEB)

    Mason, N.B.; Barnham, K.W.J.; Ballard, I.M.; Zhang, J. [Imperial College, London (United Kingdom)

    2006-05-04

    The project sought to show the UK as a world leader in the field of thin film crystalline solar cells. A premise was that the cell design be suitable for large-scale manufacturing and provide a basis for industrial exploitation. The study demonstrated (1) that silicon films grown at temperatures suitable for deposition on glass by Gas Phase Molecular Beam Epitaxy gives better PV cells than does Ultra Low Pressure Chemical Vapor Deposition; (2) a conversion energy of 15 per cent was achieved - the project target was 18 per cent and (3) one of the highest reported conversion efficiencies for a 15 micrometre silicon film was achieved. The study was carried out by BP Solar Limited under contract to the DTI.

  13. Multiferroic fluoride BaCoF4 Thin Films Grown Via Molecular Beam Epitaxy

    Science.gov (United States)

    Borisov, Pavel; Johnson, Trent; García-Castro, Camilo; Kc, Amit; Schrecongost, Dustin; Cen, Cheng; Romero, Aldo; Lederman, David

    Multiferroic materials exhibit exciting physics related to the simultaneous presence of multiple long-range orders, in many cases consisting of antiferromagnetic (AF) and ferroelectric (FE) orderings. In order to provide a new, promising route for fluoride-based multiferroic material engineering, we grew multiferroic fluoride BaCoF4 in thin film form on Al2O3 (0001) substrates by molecular beam epitaxy. The films grow with the orthorhombic b-axis out-of-plane and with three in-plane structural twin domains along the polar c-axis directions. The FE ordering in thin films was verified by FE remanent hysteresis loops measurements at T = 14 K and by room temperature piezoresponse force microscopy (PFM). An AF behavior was found below Neel temperature TN ~ 80 K, which is in agreement with the bulk properties. At lower temperatures two additional magnetic phase transitions at 19 K and 41 K were found. First-principles calculations demonstrated that the growth strain applied to the bulk BaCoF4 indeed favors two canted spin orders, along the b- and a-axes, respectively, in addition to the main AF spin order along the c-axis. Supported by FAME (Contract 2013-MA-2382), WV Research Challenge Grant (HEPC.dsr.12.29), and DMREF-NSF 1434897.

  14. Surface molecular aggregation structure and surface physicochemical properties of poly(fluoroalkyl acrylate) thin films

    International Nuclear Information System (INIS)

    Honda, K; Yamaguchi, H; Takahara, A; Kobayashi, M; Morita, M

    2008-01-01

    Effect of side chain length on the molecular aggregation states and surface properties of poly(fluoroalkyl acrylate)s [PFA-C y , where y is fluoromethylene number in R f group] thin films were systematically investigated. Spin-coated PFA-C y thin films were characterized by static and dynamic contact angle measurements, X-ray photoelectron spectroscopy (XPS), and grazing- incidence X-ray diffraction (GIXD). The receding contact angles showed small values for PFA-C y with short side chain (y≤6) and increased above y≥8. GIXD revealed that fluoroalkyl side chain of PFA-C y with y≥8 was crystallized and formed ordered structures at the surface region as well as bulk one. These results suggest that water repellent mechanism of PFA-C y can be attributed to the presence of highly ordered fluoroalkyl side chains at the outermost surfaces. The results of XPS in the dry and hydrated states and contact angle measurement in water support the mechanism of lowering contact angle for water by exposure of carbonyl group to the water interface through reorientation of short fluoroalkyl chains. The surface nanotextured PFA-C 8 through imprinting of anodic aluminum oxide mold showed extremely high hydrophobicity as well as high oleophobicity

  15. Characterization of orientational order in π-conjugated molecular thin films by NEXAFS

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Tobias, E-mail: tobias.breuer@physik.uni-marburg.de; Klues, Michael; Witte, Gregor

    2015-10-01

    Highlights: • The application of NEXAFS for orientation analysis in organic layers is reviewed. • The important effects of crystalline packing motifs on the dichroism of NEXAFS spectra are described. • Probe depth and surface-sensitivity of NEXAFS are discussed by comparing the various acquisition modes. • Possible parasitic signals and ambiguities of derived structural information are discussed. - Abstract: Enabled by the improved availability of synchrotron facilities, near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has become a widely used technique, especially due to its tunable, potentially very high, surface-sensitivity and its capability of analyzing the electronic structure of unoccupied orbitals. In this article we describe the fundamentals and technical requirements for NEXAFS spectroscopy with special focus on its application to the structural characterization of organic thin films. Based on prominent examples we discuss typical experimental applications of this technique and their characteristics compared to complementary methods. Since the evaluation of NEXAFS measurements is not straight-forward and allows for objectionable misinterpretations, we discuss numerous parasitic and often unattended effects which complicate the reliable analysis of NEXAFS spectra. Especially for the case of orientation determinations by means of NEXAFS using dichroisms analyses, the effects of molecular geometry and crystal packing motifs are elucidated in detail to provide a comprehensive picture on potential obstacles which often occur during the study of organic thin films.

  16. Thin film growth of CaFe2As2 by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Hatano, T; Fujimoto, R; Nakamura, I; Mori, Y; Ikuta, H; Kawaguchi, T; Harada, S; Ujihara, T

    2016-01-01

    Film growth of CaFe 2 As 2 was realized by molecular beam epitaxy on six different substrates that have a wide variation in the lattice mismatch to the target compound. By carefully adjusting the Ca-to-Fe flux ratio, we obtained single-phase thin films for most of the substrates. Interestingly, an expansion of the CaFe 2 As 2 lattice to the out-of-plane direction was observed for all films, even when an opposite strain was expected. A detailed microstructure observation of the thin film grown on MgO by transmission electron microscope revealed that it consists of cube-on-cube and 45°-rotated domains. The latter domains were compressively strained in plane, which caused a stretching along the c-axis direction. Because the domains were well connected across the boundary with no appreciable discontinuity, we think that the out-of-plane expansion in the 45°-rotated domains exerted a tensile stress on the other domains, resulting in the unexpectedly large c-axis lattice parameter, despite the apparently opposite lattice mismatch. (paper)

  17. Thin film growth of CaFe2As2 by molecular beam epitaxy

    Science.gov (United States)

    Hatano, T.; Kawaguchi, T.; Fujimoto, R.; Nakamura, I.; Mori, Y.; Harada, S.; Ujihara, T.; Ikuta, H.

    2016-01-01

    Film growth of CaFe2As2 was realized by molecular beam epitaxy on six different substrates that have a wide variation in the lattice mismatch to the target compound. By carefully adjusting the Ca-to-Fe flux ratio, we obtained single-phase thin films for most of the substrates. Interestingly, an expansion of the CaFe2As2 lattice to the out-of-plane direction was observed for all films, even when an opposite strain was expected. A detailed microstructure observation of the thin film grown on MgO by transmission electron microscope revealed that it consists of cube-on-cube and 45°-rotated domains. The latter domains were compressively strained in plane, which caused a stretching along the c-axis direction. Because the domains were well connected across the boundary with no appreciable discontinuity, we think that the out-of-plane expansion in the 45°-rotated domains exerted a tensile stress on the other domains, resulting in the unexpectedly large c-axis lattice parameter, despite the apparently opposite lattice mismatch.

  18. Laser molecular beam epitaxy of ZnO thin films and heterostructures

    International Nuclear Information System (INIS)

    Opel, Matthias; Geprägs, Stephan; Althammer, Matthias; Brenninger, Thomas; Gross, Rudolf

    2014-01-01

    We report on the growth of epitaxial ZnO thin films and ZnO-based heterostructures on sapphire substrates by laser molecular beam epitaxy (MBE). We first discuss some recent developments in laser-MBE such as flexible ultraviolet laser beam optics, infrared laser heating systems or the use of atomic oxygen and nitrogen sources, and describe the technical realization of our advanced laser-MBE system. Then we describe the optimization of the deposition parameters for ZnO films such as laser fluence and substrate temperature and the use of buffer layers. The detailed structural characterization by x-ray analysis and transmission electron microscopy shows that epitaxial ZnO thin films with high structural quality can be achieved, as demonstrated by a small out-of-plane and in-plane mosaic spread as well as the absence of rotational domains. We also demonstrate the heteroepitaxial growth of ZnO-based multilayers as a prerequisite for spin transport experiments and the realization of spintronic devices. As an example, we show that TiN/Co/ZnO/Ni/Au multilayer stacks can be grown on (0 0 0 1)-oriented sapphire with good structural quality of all layers and well defined in-plane epitaxial relations. (paper)

  19. Molecular Engineering for Enhanced Charge Transfer in Thin-Film Photoanode.

    Science.gov (United States)

    Kim, Jeong Soo; Kim, Byung-Man; Kim, Un-Young; Shin, HyeonOh; Nam, Jung Seung; Roh, Deok-Ho; Park, Jun-Hyeok; Kwon, Tae-Hyuk

    2017-10-11

    We developed three types of dithieno[3,2-b;2',3'-d]thiophene (DTT)-based organic sensitizers for high-performance thin photoactive TiO 2 films and investigated the simple but powerful molecular engineering of different types of bonding between the triarylamine electron donor and the conjugated DTT π-bridge by the introduction of single, double, and triple bonds. As a result, with only 1.3 μm transparent and 2.5-μm TiO 2 scattering layers, the triple-bond sensitizer (T-DAHTDTT) shows the highest power conversion efficiency (η = 8.4%; V OC = 0.73 V, J SC = 15.4 mA·cm -2 , and FF = 0.75) in an iodine electrolyte system under one solar illumination (AM 1.5, 1000 W·m -2 ), followed by the single-bond sensitizer (S-DAHTDTT) (η = 7.6%) and the double-bond sensitizer (D-DAHTDTT) (η = 6.4%). We suggest that the superior performance of T-DAHTDTT comes from enhanced intramolecular charge transfer (ICT) induced by the triple bond. Consequently, T-DAHTDTT exhibits the most active photoelectron injection and charge transport on a TiO 2 film during operation, which leads to the highest photocurrent density among the systems studied. We analyzed these correlations mainly in terms of charge injection efficiency, level of photocharge storage, and charge-transport kinetics. This study suggests that the molecular engineering of a triple bond between the electron donor and the π-bridge of a sensitizer increases the performance of dye-sensitized solar cell (DSC) with a thin photoactive film by enhancing not only J SC through improved ICT but also V OC through the evenly distributed sensitizer surface coverage.

  20. Relationship between squeezing and entangled state transformations

    CERN Document Server

    Fan Hong Yi

    2003-01-01

    We show that c-number dilation transform in the Einstein-Podolsky-Rosen (EPR) entangled state, i.e. vertical bar eta sub 1 , eta sub 2) -> vertical bar eta sub 1 , eta sub 2 /mu) (or vertical bar eta sub 1 , eta sub 2) -> vertical bar eta sub 1 /mu, eta sub 2)), maps onto a kind of one-sided two-mode squeezing operator exp left brace i lambda/2(P sub 1 + P sub 2)(Q sub 1 + Q sub 2) - lambda/2 right brace, (or exp left brace i lambda/2(P sub 1 - P sub 2)(Q sub 1 - Q sub 2) - lambda/2 right brace). Using the IWOP technique, we derive their normally ordered form and construct the corresponding squeezed states. In doing so, some new relationship between squeezing and entangled state transformation is revealed. The dynamic Hamiltonian for such a kind of squeezing evolution is derived. The properties and application of the one-sided squeezed state are briefly discussed. These states can also be obtained with the use of a beam splitter.

  1. Versatile Gaussian probes for squeezing estimation

    Science.gov (United States)

    Rigovacca, Luca; Farace, Alessandro; Souza, Leonardo A. M.; De Pasquale, Antonella; Giovannetti, Vittorio; Adesso, Gerardo

    2017-05-01

    We consider an instance of "black-box" quantum metrology in the Gaussian framework, where we aim to estimate the amount of squeezing applied on an input probe, without previous knowledge on the phase of the applied squeezing. By taking the quantum Fisher information (QFI) as the figure of merit, we evaluate its average and variance with respect to this phase in order to identify probe states that yield good precision for many different squeezing directions. We first consider the case of single-mode Gaussian probes with the same energy, and find that pure squeezed states maximize the average quantum Fisher information (AvQFI) at the cost of a performance that oscillates strongly as the squeezing direction is changed. Although the variance can be brought to zero by correlating the probing system with a reference mode, the maximum AvQFI cannot be increased in the same way. A different scenario opens if one takes into account the effects of photon losses: coherent states represent the optimal single-mode choice when losses exceed a certain threshold and, moreover, correlated probes can now yield larger AvQFI values than all single-mode states, on top of having zero variance.

  2. LHC Report: Preparing for a tighter squeeze

    CERN Multimedia

    Jan Uythoven for the LHC Team

    2011-01-01

    The LHC is resuming operation after a planned period of machine development followed by a technical stop. The beams returned last Friday, in the evening of 2 September, and preparations are now being made to squeeze the beams further at the collision points, aiming for new luminosity records.   To obtain as many collisions as possible in the heart of the experiments, the beams are squeezed to very small beam sizes. The beam squeezing parameter is known by experts as beta-star: the smaller the ß*, the stronger the squeezing. During the machine development period that started on 24 August, tests were made for the high-luminosity experiments ATLAS and CMS with ß* values of 1 m instead of the 1.5 m used previously. Unfortunately these tests were only partially successful, as some of the beam was lost during the squeezing process. It is thought that the beam losses were caused by the collimators, which were moved closer to the beam, and by the reduced crossing angle of the beams at ...

  3. Simulation of the energy spectra of original versus recombined H2+ molecular ions transmitted through thin foils

    International Nuclear Information System (INIS)

    Barriga-Carrasco, Manuel D.; Garcia-Molina, Rafael

    2004-01-01

    This work presents the results of computer simulations for the energy spectra of original versus recombined H 2 + molecular ions transmitted through thin amorphous carbon foils, for a broad range of incident energies. A detailed description of the projectile motion through the target has been done, including nuclear scattering and Coulomb repulsion as well as electronic self-retarding and wake forces; the two latter are calculated in the dielectric formalism framework. Differences in the energy spectra of recombined and original transmitted H 2 + molecular ions clearly appear in the simulations, in agreement with the available experimental data. Our simulation code also differentiates the contributions due to original and to recombined H 2 + molecular ions when the energy spectra contain both contributions, a feature that could be used for experimental purposes in estimating the ratio between the number of original and recombined H 2 + molecular ions transmitted through thin foils

  4. Thin films of molecular materials synthesized from fisher's carbene ferrocenyl: Film formation and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Vergara, M.E. [Coordinacion de Ingenieria Mecatronica. Escuela de Ingenieria, Universidad Anahuac del Norte. Avenida Lomas de la Anahuac s/n, Col. Lomas Anahuac, 52786, Huixquilucan (Mexico)], E-mail: elena.sanchez@anahuac.mx; Ortiz, A. [Instituto de Investigaciones en Materiales. Universidad Nacional Autonoma de Mexico. A. P. 70-360, 04510, Mexico, DF (Mexico); Alvarez-Toledano, C.; Moreno, A. [Instituto de Quimica, Universidad Nacional Autonoma de Mexico. Circuito Exterior, Ciudad Universitaria, 04510, Mexico, DF (Mexico); Alvarez, J.R. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Ciudad de Mexico. Calle del Puente 222, Col. Ejidos de Huipulco, 14380, Mexico, DF (Mexico)

    2008-07-31

    The synthesis of materials from Fisher's carbene ferrocenyl of the elements chromium, molybdenum and tungsten was carried out. The Fisher's compounds that were synthesized included the following combinations of two different metallic atoms: iron with chromium, iron with molybdenum and iron with tungsten. The molecular solids' preparation was done in electro-synthesis cells with platinum electrodes. Thin films were prepared by vacuum thermal evaporation on quartz substrates and crystalline silicon wafers. Pellets and thin films from these compounds were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, atomic force microscopy and ellipsometry. The powder and thin films synthesized from these materials show the same intra-molecular bonds shown by infrared spectroscopy results, suggesting that thermal evaporation does not alter these bonds in spite of the thin films being amorphous, in contrast with other bimetallic complexes where material decomposition occurs. The differences in the conductivity values of the prepared films are very small, so they may be attributed to the different metallic ions employed in each case. The tungsten complex exhibits a higher conductivity than the molybdenum and chromium complexes at room temperature. Electrical conductivity values found for thin films are higher than for pellets made of the same molecular materials.

  5. Squeezed State Caused by Inverse of Photon Creation Operator

    International Nuclear Information System (INIS)

    Xu Xuefen

    2006-01-01

    Using the photon creation operator's eigenstate theory we derive the normally ordered expansion of inverse of the squeezed creation operator. It turns out that using this operator a kind of excitation on the squeezed vacuum states can be formed.

  6. Minimum uncertainty and squeezing in diffusion processes and stochastic quantization

    Science.gov (United States)

    Demartino, S.; Desiena, S.; Illuminati, Fabrizo; Vitiello, Giuseppe

    1994-01-01

    We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.

  7. Graphene Squeeze-Film Pressure Sensors.

    Science.gov (United States)

    Dolleman, Robin J; Davidovikj, Dejan; Cartamil-Bueno, Santiago J; van der Zant, Herre S J; Steeneken, Peter G

    2016-01-13

    The operating principle of squeeze-film pressure sensors is based on the pressure dependence of a membrane's resonance frequency, caused by the compression of the surrounding gas which changes the resonator stiffness. To realize such sensors, not only strong and flexible membranes are required, but also minimization of the membrane's mass is essential to maximize responsivity. Here, we demonstrate the use of a few-layer graphene membrane as a squeeze-film pressure sensor. A clear pressure dependence of the membrane's resonant frequency is observed, with a frequency shift of 4 MHz between 8 and 1000 mbar. The sensor shows a reproducible response and no hysteresis. The measured responsivity of the device is 9000 Hz/mbar, which is a factor 45 higher than state-of-the-art MEMS-based squeeze-film pressure sensors while using a 25 times smaller membrane area.

  8. Secure quantum key distribution using squeezed states

    International Nuclear Information System (INIS)

    Gottesman, Daniel; Preskill, John

    2001-01-01

    We prove the security of a quantum key distribution scheme based on transmission of squeezed quantum states of a harmonic oscillator. Our proof employs quantum error-correcting codes that encode a finite-dimensional quantum system in the infinite-dimensional Hilbert space of an oscillator, and protect against errors that shift the canonical variables p and q. If the noise in the quantum channel is weak, squeezing signal states by 2.51 dB (a squeeze factor e r =1.34) is sufficient in principle to ensure the security of a protocol that is suitably enhanced by classical error correction and privacy amplification. Secure key distribution can be achieved over distances comparable to the attenuation length of the quantum channel

  9. Photon statistics, antibunching and squeezed states

    International Nuclear Information System (INIS)

    Leuchs, G.

    1986-01-01

    This paper attempts to describe the status and addresses future prospects of experiments regarding photon antibunching, and squeezed states. Light correlation is presented in the framework of classical electrodynamics. The extension to quantized radiation fields is discussed and an introduction to the basic principles related to photon statistics, antibunching and squeezed states are presented. The effect of linear attenuation (beam splitters, neutral density filters, and detector quantum efficiency) on the detected signal is discussed. Experiments on the change of photon statistics by the nonlinear interaction of radiation fields with matter are described and some experimental observations of antibunching and sub-Poissonian photon statistics in resonance fluorescence and with possible schemes for the generation and detection of squeezed states are examined

  10. Nonlinear Squeeze Film Dampers without Centralized Springs

    Directory of Open Access Journals (Sweden)

    Zhu Changsheng

    2000-01-01

    Full Text Available In this paper, the bifurcation behavior of a flexible rotor supported on nonlinear squeeze film dampers without centralized springs is analyzed numerically by means of rotor trajectories, Poincar maps, bifurcation diagrams and power spectra, based on the short bearing and cavitated film assumptions. It is shown that there also exist two different operations (i.e., socalled bistable operations in some speed regions in the rotor system supported on the nonlinear squeeze film dampers without centralized springs. In the bistable operation speed regions, the rotor system exhibits synchronous, sub-synchronous, sub-super-synchronous and almost-periodic as well as nonperiodic motions. The periodic bifurcation behaviors of the rotor system supported on nonlinear squeeze film dampers without centralized springs are very complex and require further investigations.

  11. Planar quantum squeezing and atom interferometry

    Energy Technology Data Exchange (ETDEWEB)

    He, Q. Y.; Drummond, P. D.; Reid, M. D. [ARC Centre of Excellence for Quantum-Atom Optics, Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia); Peng Shiguo [Department of Physics, Tsinghua University, Beijing 100084 (China)

    2011-08-15

    We obtain a lower bound on the sum of two orthogonal spin component variances in a plane. This gives a planar uncertainty relation which holds even when the Heisenberg relation is not useful. We investigate the asymptotic, large-J limit and derive the properties of the planar quantum squeezed states that saturate this uncertainty relation. These states extend the concept of spin squeezing to any two conjugate spin directions. We show that planar quantum squeezing can be achieved experimentally as the ground state of a Bose-Einstein condensate in two coupled potential wells with a critical attractive interaction. These states reduce interferometric phase noise at all phase angles simultaneously. This is useful for one-shot interferometric phase measurements where the measured phase is completely unknown. Our results can also be used to derive entanglement criteria for multiple spins J at separated sites, with applications in quantum information.

  12. Molecular beam epitaxy growth of InSb1-xBix thin films

    DEFF Research Database (Denmark)

    Yuxin Song; Shumin Wang; Saha Roy, Ivy

    2013-01-01

    Molecular beam epitaxy growth for InSb1-xBix thin films on (100) GaAs substrates is reported. Successful Bi incorporation for 2% is achieved, and up to 70% of the incorporated Bi atoms are at substitutional sites. The effects of growth parameters on Bi incorporation and surface morphology are stu...

  13. Oxygen engineering of HfO{sub 2-x} thin films grown by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institut fuer Materialwissenschaft, TU-Darmstadt (Germany); Zaumseil, Peter; Schroeder, Thomas [IHP, Frankfurt, Oder (Germany)

    2010-07-01

    Reactive molecular beam epitaxy (R-MBE) is an ideal tool for tailoring physical properties of thin films to specific needs. For the development of cutting-edge oxides for thin film applications a precise control of oxygen defects is crucial. R-MBE in combination with rf-activated oxygen allows reproducibly growing oxide thin films with precise oxidation conditions enabling oxygen engineering. R-MBE was used to grow Hf and HfO{sub 2{+-}}{sub x} thin films with different oxidation conditions on sapphire single crystal substrates. Structural characterization was carried out using rotating anode x-ray diffraction revealing highly textured to epitaxial thin films on c-cut sapphire. Furthermore, switching of film orientation by varying the oxidation conditions was observed demonstrating the role of oxygen in the growth procedure. The investigation of electrical properties using a four probe measurement setup showed conductivities in the range of 1000 {mu}{omega}cm for oxygen deficient HfO{sub 2-x} thin films. Optical properties were investigated using a photospectrometer and additionally x-ray photoelectron spectroscopy was carried out to study the band gap and valence states. Both techniques were used to monitor the oxygen content in deficient HfO{sub 2-x} thin films. Our results demonstrate the importance of oxygen engineering even in the case of 'simple' oxides.

  14. Porous squeeze-film flow

    KAUST Repository

    Knox, D. J.; Wilson, S. K.; Duffy, B. R.; McKee, S.

    2013-01-01

    surface moving under a prescribed constant load and a flat thin porous bed coating a stationary flat impermeable surface is considered. Unlike in the classical case of an impermeable bed, in which an infinite time is required for the two surfaces to touch

  15. Spatially single-mode source of bright squeezed vacuum

    OpenAIRE

    Pérez, A. M.; Iskhakov, T. Sh.; Sharapova, P.; Lemieux, S.; Tikhonova, O. V.; Chekhova, M. V.; Leuchs, G.

    2014-01-01

    Bright squeezed vacuum, a macroscopic nonclassical state of light, can be obtained at the output of a strongly pumped non-seeded traveling-wave optical parametric amplifier (OPA). By constructing the OPA of two consecutive crystals separated by a large distance we make the squeezed vacuum spatially single-mode without a significant decrease in the brightness or squeezing.

  16. Demonstration of deterministic and high fidelity squeezing of quantum information

    DEFF Research Database (Denmark)

    Yoshikawa, J-I.; Hayashi, T-; Akiyama, T.

    2007-01-01

    , and an ancillary squeezed vacuum state, thus direct interaction between a strong pump and the quantum state is circumvented. We demonstrate three different squeezing levels for a coherent state input. This scheme is highly suitable for the fault-tolerant squeezing transformation in a continuous variable quantum...... computer....

  17. Multiphoton states and amplitude k-th power squeezing

    International Nuclear Information System (INIS)

    Buzek, V.; Jex, I.

    1991-01-01

    On the basis of the work of d'Ariano and coworkers a new type of multiphoton states is introduced. Amplitude k-th power squeezing of the multiphoton states are analysed. In particular, it is shown that even if the multiphoton states do not exhibit ordinary squeezing they can be amplitude k-th power squeezed

  18. Synthesis of Sub-10 nm Two-Dimensional Covalent Organic Thin Film with Sharp Molecular Sieving Nanofiltration

    KAUST Repository

    Gadwal, Ikhlas

    2018-04-06

    We demonstrated here a novel and facile synthesis of two-dimensional (2D) covalent organic thin film with pore size around 1.5 nm using a planar, amphiphilic and substituted heptacyclic truxene based triamine and a simple dialdehyde as building blocks by dynamic imine bond formation at the air/water interface using Langmuir–Blodgett (LB) method. Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), all unanimously showed the formation of large, molecularly thin and free-standing membrane that can be easily transferred on different substrate surfaces. The 2D membrane supported on a porous polysulfone showed a rejection rate of 64 and 71% for NaCl and MgSO4, respectively, and a clear molecular sieving at molecular size around 1.3 nm, which demonstrated a great potential in the application of pretreatment of seawater desalination and separation of organic molecules.

  19. Experimental Generation of Multimode Squeezing in an Optical Parametric Amplifier

    International Nuclear Information System (INIS)

    Liu Kui; Cui Shu-Zhen; Yang Rong-Guo; Zhang Jun-Xiang; Gao Jiang-Rui

    2012-01-01

    We experimentally demonstrate that HG 01 (Hermit—Gauss) and HG 10 squeezed states can be generated simultaneously in an optical parametric amplifier. The HG 01 mode is a bright squeezed state and the HG 10 mode is a vacuum squeezed state. The squeezing of the HG 01 mode is −2.8 dB, and the squeezing of the HG 10 mode is −1.6 dB. We also demonstrate that the output field is also continuous-variable entanglement with orbital angular momentum. (general)

  20. Squeezing of Collective Excitations in Spin Ensembles

    DEFF Research Database (Denmark)

    Kraglund Andersen, Christian; Mølmer, Klaus

    2012-01-01

    We analyse the possibility to create two-mode spin squeezed states of two separate spin ensembles by inverting the spins in one ensemble and allowing spin exchange between the ensembles via a near resonant cavity field. We investigate the dynamics of the system using a combination of numerical an...

  1. Squeezing more from a quantum nondemolition measurement

    DEFF Research Database (Denmark)

    Buchler, B.C.; Lam, P.K.; Bachor, H.A.

    2002-01-01

    We use a stable, 5 dB, amplitude squeezed source for a quantum nondomolition (QND) experiment. The performance of our QND system is enhanced by an electro-optic feedforward loop which improve,, the signal transfer efficiency. At best, we measure a total signal transfer of 1.81 and conditional var...

  2. Squeezing-enhanced optomechanical transduction sensitivity

    DEFF Research Database (Denmark)

    Hoff, Ulrich Busk; Harris, Glen I.; Madsen, Lars Skovgaard

    2013-01-01

    mechanical systems. Following the proposal of Caves we have experimentally proven the applicability of squeezed light-enhanced interferometric displacement detection in the domain of micromechanical oscillators. The technique has previously been demonstrated for table-top interferometer setups and GW...

  3. Quantum teleportation of entangled squeezed vacuum states

    Institute of Scientific and Technical Information of China (English)

    蔡新华

    2003-01-01

    An optical scheme for probabilistic teleporting entangled squeezed vacuum states (SVS) is proposed. In this scheme,the teleported state is a bipartite entangled SVS,and the quantum channel is a tripartite entangled SVS.The process of the teleportation is achieved by using a 50/50 symmetric beamsplitter and photon detectors with the help of classical information.

  4. Tubes, Mono Jets, Squeeze Out and CME

    Energy Technology Data Exchange (ETDEWEB)

    Longacre, R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-10-23

    Glasma Flux Tubes, Mono Jets with squeeze out flow around them plus the Chiral Magnetic Effect(CME) are physical phenomenon that generate two particle correlation with respect to the reaction plane in mid-central 20% to 30% Au-Au collision √sNN = 200.0 GeV measured at RHIC.

  5. Squeezing corrections to the Bloch equations

    International Nuclear Information System (INIS)

    Abundo, M.; Accardi, L.

    1991-01-01

    The general analysis of quantum noise shows that a squeezing noise can produce quadratic nonlinearities in the Langevin equations leading to the Bloch equations. These quadratic nonlinearities are governed by the imaginary part of the off-diagonal terms of the covariance of the noise (the squeezing terms) and imply a correction to the usual form of the Bloch equations. Here the case of spin-one nuclei subjected to squeezing noises of particular type is studied numerically. It is shown that the corrections to the Bloch equations, suggested by the theory, to the behaviour of the macroscopic nuclear polarization in a scale of times of the order of the relaxation time can be quite substantial. In the equilibrium regime, even if the qualitative behaviour of the system is the same (exponential decay), the numerical equilibrium values predicted by the theory are consistently different from those predicted by the usual Bloch equation. It is suggested that this difference might be used to test experimentally the observable effects of squeezing noises

  6. Molecular dynamics simulations of disjoining pressure effects in ultra-thin water films on a metal surface

    Science.gov (United States)

    Hu, Han; Sun, Ying

    2013-11-01

    Disjoining pressure, the excess pressure in an ultra-thin liquid film as a result of van der Waals interactions, is important in lubrication, wetting, flow boiling, and thin film evaporation. The classic theory of disjoining pressure is developed for simple monoatomic liquids. However, real world applications often utilize water, a polar liquid, for which fundamental understanding of disjoining pressure is lacking. In the present study, molecular dynamics (MD) simulations are used to gain insights into the effect of disjoining pressure in a water thin film. Our MD models were firstly validated against Derjaguin's experiments on gold-gold interactions across a water film and then verified against disjoining pressure in an argon thin film using the Lennard-Jones potential. Next, a water thin film adsorbed on a gold surface was simulated to examine the change of vapor pressure with film thickness. The results agree well with the classic theory of disjoining pressure, which implies that the polar nature of water molecules does not play an important role. Finally, the effects of disjoining pressure on thin film evaporation in nanoporous membrane and on bubble nucleation are discussed.

  7. Deterministic secure communications using two-mode squeezed states

    International Nuclear Information System (INIS)

    Marino, Alberto M.; Stroud, C. R. Jr.

    2006-01-01

    We propose a scheme for quantum cryptography that uses the squeezing phase of a two-mode squeezed state to transmit information securely between two parties. The basic principle behind this scheme is the fact that each mode of the squeezed field by itself does not contain any information regarding the squeezing phase. The squeezing phase can only be obtained through a joint measurement of the two modes. This, combined with the fact that it is possible to perform remote squeezing measurements, makes it possible to implement a secure quantum communication scheme in which a deterministic signal can be transmitted directly between two parties while the encryption is done automatically by the quantum correlations present in the two-mode squeezed state

  8. Single orientation graphene synthesized on iridium thin films grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Dangwal Pandey, A., E-mail: arti.pandey@desy.de; Grånäs, E.; Shayduk, R.; Noei, H.; Vonk, V. [Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg (Germany); Krausert, K.; Franz, D.; Müller, P.; Keller, T. F.; Stierle, A., E-mail: andreas.stierle@desy.de [Deutsches Elektronen-Synchrotron (DESY), D-22607 Hamburg (Germany); Fachbereich Physik, Universität Hamburg, D-22607 Hamburg (Germany)

    2016-08-21

    Heteroepitaxial iridium thin films were deposited on (0001) sapphire substrates by means of molecular beam epitaxy, and subsequently, one monolayer of graphene was synthesized by chemical vapor deposition. The influence of the growth parameters on the quality of the Ir films, as well as of graphene, was investigated systematically by means of low energy electron diffraction, x-ray reflectivity, x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, and atomic force microscopy. Our study reveals (111) oriented iridium films with high crystalline quality and extremely low surface roughness, on which the formation of large-area epitaxial graphene is achieved. The presence of defects, like dislocations, twins, and 30° rotated domains in the iridium films is also discussed. The coverage of graphene was found to be influenced by the presence of 30° rotated domains in the Ir films. Low iridium deposition rates suppress these rotated domains and an almost complete coverage of graphene was obtained. This synthesis route yields inexpensive, air-stable, and large-area graphene with a well-defined orientation, making it accessible to a wider community of researchers for numerous experiments or applications, including those which use destructive analysis techniques or irreversible processes. Moreover, this approach can be used to tune the structural quality of graphene, allowing a systematic study of the influence of defects in various processes like intercalation below graphene.

  9. Molecular Ionization-Desorption Analysis Source (MIDAS) for Mass Spectrometry: Thin-Layer Chromatography

    Science.gov (United States)

    Winter, Gregory T.; Wilhide, Joshua A.; LaCourse, William R.

    2016-02-01

    Molecular ionization-desorption analysis source (MIDAS), which is a desorption atmospheric pressure chemical ionization (DAPCI) type source, for mass spectrometry has been developed as a multi-functional platform for the direct sampling of surfaces. In this article, its utility for the analysis of thin-layer chromatography (TLC) plates is highlighted. Amino acids, which are difficult to visualize without staining reagents or charring, were detected and identified directly from a TLC plate. To demonstrate the full potential of MIDAS, all active ingredients from an analgesic tablet, separated on a TLC plate, were successfully detected using both positive and negative ion modes. The identity of each of the compounds was confirmed from their mass spectra and compared against standards. Post separation, the chemical signal (blue permanent marker) as reference marks placed at the origin and solvent front were used to calculate retention factor (Rf) values from the resulting ion chromatogram. The quantitative capabilities of the device were exhibited by scanning caffeine spots on a TLC plate of increasing sample amount. A linear curve based on peak are, R2 = 0.994, was generated for seven spots ranging from 50 to 1000 ng of caffeine per spot.

  10. Study of the character of the effect of various squeezing out agents on the squeezing out process

    Energy Technology Data Exchange (ETDEWEB)

    Begnazarov, T.

    1979-01-01

    Results are examined of the study of the process of squeezing out petroleum with water with additives of a chemical reagent as a multifactor experiment, carried out in laboratory conditions. The tests were carried out in inactive petroleum of the Mishkin deposits. In the capacity of the squeezing out agents, water, solutions of caustic soda, and acetic acid were used. The basic factors, affecting the process of waterless squeezing out, included porosity, permeability in respect to gas, water saturation, pressure gradient, volume of the injection of the squeezing out agent were selected. The waterless coefficient of squeezing out also shows an effect on the complete coefficient of squeezing out. As a result of the study of the paired connections, corresponding coefficients of the regression equations and correlation coefficient were produced. The difference according to the forms of the connection between the various squeezing out agent were analyzed.

  11. Low molecular weight protein enrichment on mesoporous silica thin films for biomarker discovery.

    Science.gov (United States)

    Fan, Jia; Gallagher, James W; Wu, Hung-Jen; Landry, Matthew G; Sakamoto, Jason; Ferrari, Mauro; Hu, Ye

    2012-04-17

    The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the monitoring of therapeutic efficiency.(1-3) The circulating low molecular weight proteome (LMWP) composed of small proteins shed from tissues and cells or peptide fragments derived from the proteolytic degradation of larger proteins, has been associated with the pathological condition in patients and likely reflects the state of disease.(4,5) Despite these potential clinical applications, the use of Mass Spectrometry (MS) to profile the LMWP from biological fluids has proven to be very challenging due to the large dynamic range of protein and peptide concentrations in serum.(6) Without sample pre-treatment, some of the more highly abundant proteins obscure the detection of low-abundance species in serum/plasma. Current proteomic-based approaches, such as two-dimensional polyacrylamide gel-electrophoresis (2D-PAGE) and shotgun proteomics methods are labor-intensive, low throughput and offer limited suitability for clinical applications.(7-9) Therefore, a more effective strategy is needed to isolate LMWP from blood and allow the high throughput screening of clinical samples. Here, we present a fast, efficient and reliable multi-fractionation system based on mesoporous silica chips to specifically target and enrich LMWP.(10,11) Mesoporous silica (MPS) thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different polymer templates and polymer concentrations in the precursor solution, various pore size distributions, pore structures, connectivity and surface properties were determined and applied for selective recovery of low mass proteins. The selective parsing of the enriched peptides into different subclasses according to their physicochemical properties will enhance the efficiency of recovery and detection of low abundance species. In combination with mass

  12. RESEARCH ON THE ELECTRONIC AND OPTICAL PROPERTIES OF POLYMER AND OTHER ORGANIC MOLECULAR THIN FILMS

    Energy Technology Data Exchange (ETDEWEB)

    ALEXEI G. VITUKHNOVSKY; IGOR I. SOBELMAN - RUSSIAN ACADEMY OF SCIENCES

    1995-09-06

    Optical properties of highly ordered films of poly(p-phenylene) (PPP) on different substrates, thin films of mixtures of conjugated polymers, of fullerene and its composition with polymers, molecular J-aggregates of cyanine dyes in frozen matrices have been studied within the framework of the Agreement. Procedures of preparation of high-quality vacuum deposited PPP films on different substrates (ITO, Si, GaAs and etc.) were developed. Using time-correlated single photon counting technique and fluorescence spectroscopy the high quality of PPP films has been confirmed. Dependence of structure and optical properties on the conditions of preparation were investigated. The fluorescence lifetime and spectra of highly oriented vacuum deposited PPP films were studied as a function of the degree of polymerization. It was shown for the first time that the maximum fluorescence quantum yield is achieved for the chain length approximately equal to 35 monomer units. The selective excitation of luminescence of thin films of PPP was performed in the temperature range from 5 to 300 K. The total intensity of luminescence monotonically decreases with decreasing temperature. Conditions of preparation of highly cristallyne fullerene C{sub 60} films by the method of vacuum deposition were found. Composites of C{sub 60} with conjugated polymers PPV and polyacetylene (PA) were prepared. The results on fluorescence quenching, IR and resonant Raman spectroscopy are consistent with earlier reported ultrafast photoinduced electron transfer from PPV to C{sub 60} and show that the electron transfer is absent in the case of the PA-C{sub 60} composition. Strong quenching of PPV fluorescence was observed in the PPV-PA blends. The electron transfer from PPV to PA can be considered as one of the possible mechanisms of this quenching. The dynamics of photoexcitations in different types of J-aggregates of the carbocyanine dye was studied at different temperatures in frozen matrices. The optical

  13. Combinatorial screening of halide perovskite thin films and solar cells by mask-defined IR laser molecular beam epitaxy

    OpenAIRE

    Kawashima, Kazuhiro; Okamoto, Yuji; Annayev, Orazmuhammet; Toyokura, Nobuo; Takahashi, Ryota; Lippmaa, Mikk; Itaka, Kenji; Suzuki, Yoshikazu; Matsuki, Nobuyuki; Koinuma, Hideomi

    2017-01-01

    Abstract As an extension of combinatorial molecular layer epitaxy via ablation of perovskite oxides by a pulsed excimer laser, we have developed a laser molecular beam epitaxy (MBE) system for parallel integration of nano-scaled thin films of organic?inorganic hybrid materials. A pulsed infrared (IR) semiconductor laser was adopted for thermal evaporation of organic halide (A-site: CH3NH3I) and inorganic halide (B-site: PbI2) powder targets to deposit repeated A/B bilayer films where the thic...

  14. Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films: Review of Processes and Application to Optoelectronics

    Directory of Open Access Journals (Sweden)

    Varun Vohra

    2017-01-01

    Full Text Available Semiconducting polymers are composed of elongated conjugated polymer backbones and side chains with high solubility and mechanical properties. The combination of these two features results in a high processability and a potential to orient the conjugated backbones in thin films and nanofibers. The thin films and nanofibers are usually composed of highly crystalline (high charge transport and amorphous parts. Orientation of conjugated polymer can result in enhanced charge transport or optical properties as it induces increased crystallinity or preferential orientation of the crystallites. After summarizing the potential strategies to exploit molecular order in conjugated polymer based optoelectronic devices, we will review some of the fabrication processes to induce molecular orientation. In particular, we will review the cases involving molecular and interfacial interactions, unidirectional deposition processes, electrospinning, and postdeposition mechanical treatments. The studies presented here clearly demonstrate that process-controlled molecular orientation of the conjugated polymer chains can result in high device performances (mobilities over 40 cm2·V−1·s−1 and solar cells with efficiencies over 10%. Furthermore, the peculiar interactions between molecularly oriented polymers and polarized light have the potential not only to generate low-cost and low energy consumption polarized light sources but also to fabricate innovative devices such as solar cell integrated LCDs or bipolarized LEDs.

  15. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    International Nuclear Information System (INIS)

    Li, Qibin; Peng, Xianghe; Peng, Tiefeng; Tang, Qizhong; Zhang, Xiaomin; Huang, Cheng

    2015-01-01

    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  16. Molecular dynamics simulation of Cu/Au thin films under temperature gradient

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qibin, E-mail: qibinli@cqu.edu.cn [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Peng, Xianghe [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Peng, Tiefeng, E-mail: pengtiefeng@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030 (China); Tang, Qizhong [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Xiaomin [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China); Chongqing Key Laboratory of Heterogeneous Material Mechanics, Chongqing University, Chongqing 400030 (China); Huang, Cheng [College of Aerospace Engineering, Chongqing University, Chongqing 400030 (China)

    2015-12-01

    Graphical abstract: Heat transportation in the thin films. - Highlights: • The coherent lattice interface is found at thin films after annealing. • The vacancies are observed clearly in the deposit thin films. • The defect and component will influence the energy transportation in the coatings. • The vacancies and lattice mismatch can enlarge the mobility of atoms. • The phonon transportation in thin films has no apparent rule. - Abstract: Three modulation period thin films, 1.8 nm Cu/3.6 nm Au, 2.7 nm Cu/2.7 nm Au and 3.6 nm Cu/1.8 nm Au, are obtained from deposition method and ideal modeling based on lattice constant, to examine their structures and thermophysical characteristics under temperature gradient. The coherent lattice interface is found both at deposit and ideal thin films after annealing. Also, the vacancies are observed clearly in the deposit thin films. The defect and component of thin films will influence the energy transportation in the coatings. The vacancies and lattice mismatch can enlarge the mobility of atoms and result in the failure of coating under the thermal stress. The power spectrum of atoms’ movement has no apparent rule for phonon transportation in thin films. The results are helpful to reveal the micro-mechanism and provide reasonable basis for the failure of metallic coatings.

  17. Adaptive phase estimation with squeezed thermal light

    DEFF Research Database (Denmark)

    Berni, A. A.; Madsen, Lars Skovgaard; Lassen, Mikael Østergaard

    2013-01-01

    Summary form only given. The use of quantum states of light in optical interferometry improves the precision in the estimation of a phase shift, paving the way for applications in quantum metrology, computation and cryptography. Sub-shot noise phase sensing can for example be achieved by injecting...... investigate the performances of such protocol under the realistic assumption of thermalization of the probe state. Indeed, adaptive phase estimation schemes with squeezed states and Bayesian processing of homodyne data have been shown to be asymptotically optimal in the pure case, thus approaching the quantum...... Cramér-Rao bound. In our protocol we take advantage of the enhanced sensitivity of homodyne detection in proximity of the optimal phase which maximizes the homodyne Fisher information. A squeezed thermal probe state (signal) undergoes an unknown phase shift. The first estimation step involves...

  18. Phase sensitive molecular dynamics of self-assembly glycolipid thin films: A dielectric spectroscopy investigation

    Science.gov (United States)

    Velayutham, T. S.; Ng, B. K.; Gan, W. C.; Majid, W. H. Abd.; Hashim, R.; Zahid, N. I.; Chaiprapa, Jitrin

    2014-08-01

    Glycolipid, found commonly in membranes, is also a liquid crystal material which can self-assemble without the presence of a solvent. Here, the dielectric and conductivity properties of three synthetic glycolipid thin films in different thermotropic liquid crystal phases were investigated over a frequency and temperature range of (10-2-106 Hz) and (303-463 K), respectively. The observed relaxation processes distinguish between the different phases (smectic A, columnar/hexagonal, and bicontinuous cubic Q) and the glycolipid molecular structures. Large dielectric responses were observed in the columnar and bicontinuous cubic phases of the longer branched alkyl chain glycolipids. Glycolipids with the shortest branched alkyl chain experience the most restricted self-assembly dynamic process over the broad temperature range studied compared to the longer ones. A high frequency dielectric absorption (Process I) was observed in all samples. This is related to the dynamics of the hydrogen bond network from the sugar group. An additional low-frequency mechanism (Process II) with a large dielectric strength was observed due to the internal dynamics of the self-assembly organization. Phase sensitive domain heterogeneity in the bicontinuous cubic phase was related to the diffusion of charge carriers. The microscopic features of charge hopping were modelled using the random walk scheme, and two charge carrier hopping lengths were estimated for two glycolipid systems. For Process I, the hopping length is comparable to the hydrogen bond and is related to the dynamics of the hydrogen bond network. Additionally, that for Process II is comparable to the bilayer spacing, hence confirming that this low-frequency mechanism is associated with the internal dynamics within the phase.

  19. Generalization of the Davydov Ansatz by squeezing

    Energy Technology Data Exchange (ETDEWEB)

    Grossmann, Frank; Werther, Michael [Institut für Theoretische Physik, Technische Universität Dresden, D-01062 Dresden (Germany); Chen, Lipeng; Zhao, Yang [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2016-12-20

    We propose an extension of the Davydov Ansatz employing displaced squeezed states in the oscillator Hilbert space. The Dirac–Frenkel variational principle is used to derive the modified equations for the variational parameters. First numerical studies of the dynamics of the spin-boson model with a single bosonic degree of freedom reveal an overall improvement of the results as compared to the standard Davydov Ansatz.

  20. Baryon asymmetry, inflation and squeezed states

    International Nuclear Information System (INIS)

    Bambah, Bindu A.; Chaitanya, K.V.S. Shiv; Mukku, C.

    2007-01-01

    We use the general formalism of squeezed rotated states to calculate baryon asymmetry in the wake of inflation through parametric amplification. We base our analysis on a B and CP violating Lagrangian in an isotropically expanding universe. The B and CP violating terms originate from the coupling of complex fields with non-zero baryon number to a complex background inflaton field. We show that a differential amplification of particle and antiparticle modes gives rise to baryon asymmetry

  1. Molecular dynamics simulation about porous thin-film growth in secondary deposition

    International Nuclear Information System (INIS)

    Chen Huawei; Tieu, A. Kiet; Liu Qiang; Hagiwara, Ichiro; Lu Cheng

    2007-01-01

    The thin film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters' depositions proceeds to form the thin film at short time as gas fluids through surface of substrate. In order to grow condensed thin film using series of cluster deposition, the effect of initial velocity, substrate temperature and density of clusters on property of deposited thin film, especially appearance of nanoscale pores inside thin film must be investigated. In this simulation, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000 and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. We have clarified that adhesion between clusters and substrate is greatly influenced by initial velocity. As a result, the exfoliation pattern of deposited thin film is dependent on initial velocity and different between them. One borderline dividing whole region into porous region and nonporous region are obtained to show the effect of growth conditions on appearance of nanoscale pores inside thin film. Moreover, we have also shown that the likelihood of porous thin film is dependent on the point of impact of a cluster relative to previously deposited clusters

  2. Molecular dynamics simulation about porous thin-film growth in secondary deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen Huawei [School of Mechanical Engineering and Automation, Beihang University, No. 37 Xuyuan Road, Haidian District, Beijing (China) and Mechanical Materials and Mechatronic Engineering, University of Wollongong, Northfields Avenue, NSW 2522 (Australia)]. E-mail: chen_hua_wei@yahoo.com; Tieu, A. Kiet [Mechanical Materials and Mechatronic Engineering, University of Wollongong, Northfields Avenue, NSW 2522 (Australia); Liu Qiang [School of Mechanical Engineering and Automation, Beihang University, No. 37 Xuyuan Road, Haidian District, Beijing (China); Hagiwara, Ichiro [Department of Mechanical Sciences and Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo (Japan); Lu Cheng [Mechanical Materials and Mechatronic Engineering, University of Wollongong, Northfields Avenue, NSW 2522 (Australia)

    2007-07-15

    The thin film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters' depositions proceeds to form the thin film at short time as gas fluids through surface of substrate. In order to grow condensed thin film using series of cluster deposition, the effect of initial velocity, substrate temperature and density of clusters on property of deposited thin film, especially appearance of nanoscale pores inside thin film must be investigated. In this simulation, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000 and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. We have clarified that adhesion between clusters and substrate is greatly influenced by initial velocity. As a result, the exfoliation pattern of deposited thin film is dependent on initial velocity and different between them. One borderline dividing whole region into porous region and nonporous region are obtained to show the effect of growth conditions on appearance of nanoscale pores inside thin film. Moreover, we have also shown that the likelihood of porous thin film is dependent on the point of impact of a cluster relative to previously deposited clusters.

  3. Experimental Realization of a Thermal Squeezed State of Levitated Optomechanics

    Science.gov (United States)

    Rashid, Muddassar; Tufarelli, Tommaso; Bateman, James; Vovrosh, Jamie; Hempston, David; Kim, M. S.; Ulbricht, Hendrik

    2016-12-01

    We experimentally squeeze the thermal motional state of an optically levitated nanosphere by fast switching between two trapping frequencies. The measured phase-space distribution of the center of mass of our particle shows the typical shape of a squeezed thermal state, from which we infer up to 2.7 dB of squeezing along one motional direction. In these experiments the average thermal occupancy is high and, even after squeezing, the motional state remains in the remit of classical statistical mechanics. Nevertheless, we argue that the manipulation scheme described here could be used to achieve squeezing in the quantum regime if preceded by cooling of the levitated mechanical oscillator. Additionally, a higher degree of squeezing could, in principle, be achieved by repeating the frequency-switching protocol multiple times.

  4. Transport mechanisms and wetting dynamics in molecularly thin films of long-chain alkanes at solid/vapour interface : relation to the solid-liquid phase transition

    OpenAIRE

    Lazar, Paul

    2005-01-01

    Wetting and phase transitions play a very important role our daily life. Molecularly thin films of long-chain alkanes at solid/vapour interfaces (e.g. C30H62 on silicon wafers) are very good model systems for studying the relation between wetting behaviour and (bulk) phase transitions. Immediately above the bulk melting temperature the alkanes wet partially the surface (drops). In this temperature range the substrate surface is covered with a molecularly thin ordered, solid-like alkane film (...

  5. Simulations and experiments on polarization squeezing in optical fiber

    DEFF Research Database (Denmark)

    Corney, J.F.; Heersink, J.; Dong, R.

    2008-01-01

    We investigate polarization squeezing of ultrashort pulses in optical fiber, over a wide range of input energies and fiber lengths. Comparisons are made between experimental data and quantum dynamical simulations to find good quantitative agreement. The numerical calculations, performed using both...... effects cause a marked deterioration of squeezing at higher energies and longer fiber lengths. We also calculate the optimum fiber length for maximum squeezing....

  6. Spin squeezing and entanglement in a dispersive cavity

    International Nuclear Information System (INIS)

    Deb, R. N.; Abdalla, M. Sebawe; Hassan, S. S.; Nayak, N.

    2006-01-01

    We consider a system of N two-level atoms (spins) interacting with the radiation field in a dispersive but high-Q cavity. Under an adiabatic condition, the interaction Hamiltonian reduces to a function of spin operators which is capable of producing spin squeezing. For a bipartite system (N=2), the expressions for spin squeezing get very simple, giving a clear indication of close to 100% noise reduction. We analyse this squeezing as a measure of bipartite entanglement

  7. Studying fluid squeeze characteristics for aerostatic journal bearing

    International Nuclear Information System (INIS)

    Abdel-Rahman, Gamal M.

    2008-01-01

    The Reynolds equation for studying fluid squeeze of aerostatic journal bearing is solved numerically by considering the quasi-steady behavior of the air film. The radial displacement can influence the air film thickness modifying the pressure distribution in the journal-bearing gap. Also, the variations in the seal characteristics with eccentricity, time, squeeze number, length-to-diameter and supply pressure are presented. The numerical results for the squeeze load-carrying capacity are given in a non-dimensional form

  8. A novel method for polarization squeezing with Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Milanovic, Josip; Lassen, Mikael Østergaard; Andersen, Ulrik Lund

    2010-01-01

    Photonic Crystal Fibers can be tailored to increase the effective Kerr nonlinearity, while producing smaller amounts of excess noise compared to standard silicon fibers. Using these features of Photonic Crystal Fibers we create polarization squeezed states with increased purity compared to standa...... Stokes parameter squeezing of −3.9 ±0.3dB and anti-squeezing of 16.2 ±0.3dB....

  9. Crystal-field-modulated magnon squeezing states in a ferromagnet

    International Nuclear Information System (INIS)

    Peng Feng

    2003-01-01

    The magnon squeezing states in some magnetic crystals allow a reduction in the quantum fluctuations of the spin component to below the zero-point quantum noise level of the coherent magnon states. It is known that there are the magnon squeezing states in an antiferromagnet. However, their generating mechanism is not suitable for the ferromagnet. In this paper, we discuss the possibility of generating the magnon squeezing states in a ferromagnet, and discuss the effect of the crystal field on the magnon squeezing states

  10. ESR and X-ray diffraction studies on thin films of poly-3-hexylthiophene: Molecular orientation and magnetic interactions

    International Nuclear Information System (INIS)

    Sugiyama, Keisuke; Kojima, Takashi; Fukuda, Hisashi; Yashiro, Hisashi; Matsuura, Toshihiko; Shimoyama, Yuhei

    2008-01-01

    Poly-3-hexylthiophene (P3HT) thin films were investigated by X-ray diffraction (XRD) and electron spin resonance (ESR) to reveal the film structure and molecular organization. The XRD data showed a diffraction pattern with a plane separation between the planes containing thiophene rings of 16.0 A. Comparison between the XRD patterns of powder and thin films of P3HT suggests that the main chains are folded on the substrate. Angular variation of the line position (g-value) of ESR spectra revealed that thiophene ring of P3HT orients along the substrate normal axis. The ESR linewidth varied by the angular rotation, indicating the one-dimensional spin-chain interactions in the P3HT thin films with a linear network of spin-chains. An organic thin-film transistor (OTFT) with P3HT film as a channel layer was then demonstrated. The P3HT films showed conducting characteristics with holes as carriers. The OTFTs indicated a field-effect mobility of 4.93 x 10 -3 cm 2 /Vs and an on/off ratio of 73 in the accumulation mode

  11. Effect of twin boundary on nanoimprint process of bicrystal Al thin film studied by molecular dynamics simulation

    International Nuclear Information System (INIS)

    Xie Yue-Hong; Xu Jian-Gang; Zhang Yun-Guang; Song Hai-Yang

    2015-01-01

    The effects of a twin boundary (TB) on the mechanical properties of two types of bicrystal Al thin films during the nanoimprint process are investigated by using molecular dynamics simulations. The results indicate that for the TB direction parallel to the imprinting direction, the yield stress reaches the maximum for the initial dislocation nucleation when the mould directly imprints to the TB, and the yield stress first decreases with the increase of the marker interval and then increases. However, for the TB direction perpendicular to the imprinting direction, the effect of the TB location to the imprinting forces is very small, and the yield stress is greater than that with the TB direction parallel to the imprinting direction. The results also demonstrate that the direction of the slip dislocations and the deformation of the thin film caused by spring-back are different due to various positions and directions of the TB. (paper)

  12. Non-collinear configuration for dichromatic squeezing

    Energy Technology Data Exchange (ETDEWEB)

    Andreoni, A.; Bondani, M. [Como Univ. (Italy). Dipt. di Scienze Chimiche Fisiche e Matematiche; Mauro D' Ariano, G.; Paris, M.G.A. [Como Univ. (Italy). Dipt. di Scienze Chimiche Fisiche e Matematiche; Quantum Optics Group, Unita INFM and Dipt. di Fisica ' Alessandro Volta' , Univ. di Pavia (Italy)

    2001-02-01

    We propose a non-collinear experimental scheme for the joint generation of two amplitude-squeezed beams at the frequencies {omega}{sub 1} and {omega}{sub 2}, fundamental and second harmonics of a Nd:YAG laser pulse. The scheme consists of two successive steps, both involving second-order non-linear interactions in {beta}-BaB{sub 2}O{sub 4} non-linear crystals. One of the output beams show subPoissonian photon statistics, and this allows to use photodetection instead of homodyne detection for diagnostics. (orig.)

  13. Non-collinear configuration for dichromatic squeezing

    International Nuclear Information System (INIS)

    Andreoni, A.; Bondani, M.

    2001-01-01

    We propose a non-collinear experimental scheme for the joint generation of two amplitude-squeezed beams at the frequencies ω 1 and ω 2 , fundamental and second harmonics of a Nd:YAG laser pulse. The scheme consists of two successive steps, both involving second-order non-linear interactions in β-BaB 2 O 4 non-linear crystals. One of the output beams show subPoissonian photon statistics, and this allows to use photodetection instead of homodyne detection for diagnostics. (orig.)

  14. Integrated source of broadband quadrature squeezed light

    DEFF Research Database (Denmark)

    Hoff, Ulrich Busk; Nielsen, Bo Melholt; Andersen, Ulrik Lund

    2015-01-01

    An integrated silicon nitride resonator is proposed as an ultracompact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing...... the device. An asymmetric double layer stack waveguide geometry with inverse vertical tapers is proposed for efficient and robust fibre-chip coupling, yielding a simulated total loss of -0.75 dB/facet. We assess the feasibility of the device through a full quantum noise analysis and derive the output...

  15. Improving stability of photoluminescence of ZnSe thin films grown by molecular beam epitaxy by incorporating Cl dopant

    International Nuclear Information System (INIS)

    Wang, J. S.; Shen, J. L.; Chen, W. J.; Tsai, Y. H.; Wang, H. H.; Yang, C. S.; Chen, R. H.; Tsai, C. D.

    2011-01-01

    This investigation studies the effect of chlorine (Cl) dopant in ZnSe thin films that were grown by molecular beam epitaxy on their photoluminescence (PL) and the stability thereof. Free excitonic emission was observed at room-temperature in the Cl-doped sample. Photon irradiation with a wavelength of 404 nm and a power density of 9.1 W/cm 2 has a much stronger effect on PL degradation than does thermal heating to a temperature of 150 deg. C. Additionally, this study shows that the generation of nonradiative centers by both photon irradiation and thermal heating can be greatly inhibited by incorporating Cl dopant.

  16. Thermally induced self-assembly of cylindrical nanodomains in low molecular weight PS-b-PMMA thin films

    International Nuclear Information System (INIS)

    Seguini, Gabriele; Giammaria, Tommaso J; Lupi, Federico Ferrarese; Perego, Michele; Sparnacci, Katia; Antonioli, Diego; Gianotti, Valentina; Laus, Michele; Vita, Francesco; Placentino, Immacolata F; Francescangeli, Oriano; Hilhorst, Jan; Ferrero, Claudio

    2014-01-01

    The phase behaviour in thin films of an asymmetric polystyrene-b-polymethylmethacrylate (PS-b-PMMA) block copolymer with a molecular weight of 39 kg mol −1 was assessed at a wide range of temperatures and times. Cylindrical PMMA structures featuring a diameter close to 10 nm and perpendicularly oriented with respect to the substrate were obtained at 180 ° C in relatively short annealing times (t ≤ 30 min) by means of a simple thermal treatment performed in a standard rapid thermal processing machine. (paper)

  17. Epitaxial growth of SrTiO3 thin film on Si by laser molecular beam epitaxy

    International Nuclear Information System (INIS)

    Zhou, X. Y.; Miao, J.; Dai, J. Y.; Chan, H. L. W.; Choy, C. L.; Wang, Y.; Li, Q.

    2007-01-01

    SrTiO 3 thin films have been deposited on Si (001) wafers by laser molecular beam epitaxy using an ultrathin Sr layer as the template. X-ray diffraction measurements indicated that SrTiO 3 was well crystallized and epitaxially aligned with Si. Cross-sectional observations in a transmission electron microscope revealed that the SrTiO 3 /Si interface was sharp, smooth, and fully crystallized. The thickness of the Sr template was found to be a critical factor that influenced the quality of SrTiO 3 and the interfacial structure. Electrical measurements revealed that the SrTiO 3 film was highly resistive

  18. Molecular fouling resistance of zwitterionic and amphiphilic initiated chemically vapor-deposited (iCVD) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R; Goktekin, E; Wang, MH; Gleason, KK

    2014-08-08

    Biofouling is a universal problem in various applications ranging from water purification to implantable biomedical devices. Recent advances in surface modification have created a rich library of antifouling surface chemistries, many of which can be categorized into one of the two groups: hydrophilic surfaces or amphiphilic surfaces. We report the straightforward preparation of antifouling thin film coatings in both categories via initiated chemical vapor deposition. A molecular force spectroscopy-based method is demonstrated as a rapid and quantitative assessment tool for comparing the differences in antifouling characteristics. The fouling propensity of single molecules, as opposed to bulk protein solution or bacterial culture, is assessed. This method allows for the interrogation of molecular interaction without the complication resulted from protein conformational change or micro-organism group interactions. The molecular interaction follows the same trend as bacterial adhesion results obtained previously, demonstrating that molecular force probe is a valid method for the quantification and mechanistic examination of fouling. In addition, the molecular force spectroscopy-based method is able to distinguish differences in antifouling capability that is not resolvable by traditional static protein adsorption tests. To lend further insight into the intrinsic fouling resistance of zwitterionic and amphiphilic surface chemistries, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, advancing and receding water contact angles, and atomic force microscopy are used to elucidate the film properties that are relevant to their antifouling capabilities.

  19. Observation of squeezed states with strong photon-number oscillations

    International Nuclear Information System (INIS)

    Mehmet, Moritz; Vahlbruch, Henning; Lastzka, Nico; Danzmann, Karsten; Schnabel, Roman

    2010-01-01

    Squeezed states of light constitute an important nonclassical resource in the field of high-precision measurements, for example, gravitational wave detection, as well as in the field of quantum information, for example, for teleportation, quantum cryptography, and distribution of entanglement in quantum computation networks. Strong squeezing in combination with high purity, high bandwidth, and high spatial mode quality is desirable in order to achieve significantly improved performances contrasting any classical protocols. Here we report on the observation of 11.5 dB of squeezing, together with relatively high state purity corresponding to a vacuum contribution of less than 5%, and a squeezing bandwidth of about 170 MHz. The analysis of our squeezed states reveals a significant production of higher-order pairs of quantum-correlated photons and the existence of strong photon-number oscillations.

  20. Resonance Fluorescence from an Artificial Atom in Squeezed Vacuum

    Directory of Open Access Journals (Sweden)

    D. M. Toyli

    2016-07-01

    Full Text Available We present an experimental realization of resonance fluorescence in squeezed vacuum. We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier. We investigate the fluorescence spectra in the weak and strong driving regimes, observing up to 3.1 dB of reduction of the fluorescence linewidth below the ordinary vacuum level and a dramatic dependence of the Mollow triplet spectrum on the relative phase of the driving and squeezed vacuum fields. Our results are in excellent agreement with predictions for spectra produced by a two-level atom in squeezed vacuum [Phys. Rev. Lett. 58, 2539 (1987], demonstrating that resonance fluorescence offers a resource-efficient means to characterize squeezing in cryogenic environments.

  1. Nth-powered amplitude squeezing in fan-states

    CERN Document Server

    Duc, T M

    2002-01-01

    Squeezing properties of the Hillery-type N-powered amplitude are investigated in the fan-state vertical bar xi; 2k, f> sub F which is linearly superposed by 2k 2k-quantum nonlinear coherent states in the phase-locked manner. The general expression of squeezing is derived analytically for arbitrary xi, k, N and f showing a multi-directional character of squeezing. For a given k, squeezing may appear to the even power N=2k if f ident to 1 and N>=2k if f not =1 and the number of directions along with the Nth-powered amplitude is squeezed is exactly equal to N, for both f ident to 1 (the light field) and f not =1 (the vibrational motion of the trapped ion). Discussions are also given elucidating the qualitative difference between the cases of f ident to 1 and f not =1.

  2. Squeeze flow of a Carreau fluid during sphere impact

    KAUST Repository

    Uddin, J.

    2012-07-19

    We present results from a combined numerical and experimental investigation into the squeeze flow induced when a solid sphere impacts onto a thin, ultra-viscous film of non-Newtonian fluid. We examine both the sphere motion through the liquid as well as the fluid flow field in the region directly beneath the sphere during approach to a solid plate. In the experiments we use silicone oil as the model fluid, which is well-described by the Carreau model. We use high-speed imaging and particle tracking to achieve flow visualisation within the film itself and derive the corresponding velocity fields. We show that the radial velocity either diverges as the gap between the sphere and the wall diminishes (Z tip → 0) or that it reaches a maximum value and then decays rapidly to zero as the sphere comes to rest at a non-zero distance (Z tip = Z min ) away from the wall. The horizontal shear rate is calculated and is responsible for significant viscosity reduction during the approach of the sphere. Our model of this flow, based on lubrication theory, is solved numerically and compared to experimental trials. We show that our model is able to correctly describe the physical features of the flow observed in the experiments.

  3. Dynamic characteristics of Non Newtonian fluid Squeeze film damper

    Science.gov (United States)

    Palaksha, C. P.; Shivaprakash, S.; Jagadish, H. P.

    2016-09-01

    The fluids which do not follow linear relationship between rate of strain and shear stress are termed as non-Newtonian fluid. The non-Newtonian fluids are usually categorized as those in which shear stress depends on the rates of shear only, fluids for which relation between shear stress and rate of shear depends on time and the visco inelastic fluids which possess both elastic and viscous properties. It is quite difficult to provide a single constitutive relation that can be used to define a non-Newtonian fluid due to a great diversity found in its physical structure. Non-Newtonian fluids can present a complex rheological behaviour involving shear-thinning, viscoelastic or thixotropic effects. The rheological characterization of complex fluids is an important issue in many areas. The paper analyses the damping and stiffness characteristics of non-Newtonian fluids (waxy crude oil) used in squeeze film dampers using the available literature for viscosity characterization. Damping and stiffness characteristic will be evaluated as a function of shear strain rate, temperature and percentage wax concentration etc.

  4. Squeeze flow of a Carreau fluid during sphere impact

    KAUST Repository

    Uddin, J.; Marston, J. O.; Thoroddsen, Sigurdur T

    2012-01-01

    We present results from a combined numerical and experimental investigation into the squeeze flow induced when a solid sphere impacts onto a thin, ultra-viscous film of non-Newtonian fluid. We examine both the sphere motion through the liquid as well as the fluid flow field in the region directly beneath the sphere during approach to a solid plate. In the experiments we use silicone oil as the model fluid, which is well-described by the Carreau model. We use high-speed imaging and particle tracking to achieve flow visualisation within the film itself and derive the corresponding velocity fields. We show that the radial velocity either diverges as the gap between the sphere and the wall diminishes (Z tip → 0) or that it reaches a maximum value and then decays rapidly to zero as the sphere comes to rest at a non-zero distance (Z tip = Z min ) away from the wall. The horizontal shear rate is calculated and is responsible for significant viscosity reduction during the approach of the sphere. Our model of this flow, based on lubrication theory, is solved numerically and compared to experimental trials. We show that our model is able to correctly describe the physical features of the flow observed in the experiments.

  5. Sequence control of phase separation and dewetting in PS/PVME blend thin films by changing molecular weight of PS.

    Science.gov (United States)

    Xia, Tian; Qin, Yaping; Huang, Yajiang; Huang, Ting; Xu, Jianhui; Li, Youbing

    2016-11-28

    The morphology evolution mechanism of polystyrene (PS)/poly (vinyl methyl ether) (PVME) blend thin films with different PS molecular weights (M w ) was studied. It was found that the morphology evolution was closely related to the molecular weight asymmetry between PS and PVME. In the film where M w (PS) ≈ M w (PVME), dewetting happened at the interface between the bottom layer and substrate after SD phase separation. While in the film where M w (PS) > M w (PVME), dewetting happened at the interface between the middle PS/PVME blend layer and bottom PVME layer near the substrate prior to phase separation. The different sequences of phase separation and dewetting and different interface for dewetting occurrence were studied by regarding the competitive effects of viscoelasticity contrast between polymer components and preferential wetting between PVME and the substrate. The viscoelastic nature of the PS component played a crucial role in the sequence of phase separation and dewetting.

  6. High mobility n-type organic thin-film transistors deposited at room temperature by supersonic molecular beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chiarella, F., E-mail: fabio.chiarella@spin.cnr.it; Barra, M.; Ciccullo, F.; Cassinese, A. [CNR-SPIN and Physics Department, University of Naples, Piazzale Tecchio 80, I-80125 Naples (Italy); Toccoli, T.; Aversa, L.; Tatti, R.; Verucchi, R. [IMEM-CNR-FBK Division of Trento, Via alla Cascata 56/C, I-38123 Povo (Italy); Iannotta, S. [IMEM-CNR, Parco Area delle Scienze 37/A, I-43124 Parma (Italy)

    2014-04-07

    In this paper, we report on the fabrication of N,N′-1H,1H-perfluorobutil dicyanoperylenediimide (PDIF-CN{sub 2}) organic thin-film transistors by Supersonic Molecular Beam Deposition. The devices exhibit mobility up to 0.2 cm{sup 2}/V s even if the substrate is kept at room temperature during the organic film growth, exceeding by three orders of magnitude the electrical performance of those grown at the same temperature by conventional Organic Molecular Beam Deposition. The possibility to get high-mobility n-type transistors avoiding thermal treatments during or after the deposition could significantly extend the number of substrates suitable to the fabrication of flexible high-performance complementary circuits by using this compound.

  7. Solvent vapor annealing in the molecular regime drastically improves carrier transport in small-molecule thin-film transistors

    KAUST Repository

    Khan, Hadayat Ullah

    2013-04-10

    We demonstrate a new way to investigate and control the solvent vapor annealing of solution-cast organic semiconductor thin films. Solvent vapor annealing of spin-cast films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) is investigated in situ using quartz crystal microbalance with dissipation (QCM-D) capability, allowing us to monitor both solvent mass uptake and changes in the mechanical rigidity of the film. Using time-resolved grazing incidence wide angle X-ray scattering (GIWAXS) and complementary static atomic force microscopy (AFM), we demonstrate that solvent vapor annealing in the molecular regime can cause significant performance improvements in organic thin film transistors (OTFTs), whereas allowing the solvent to percolate and form a liquid phase results in catastrophic reorganization and dewetting of the film, making the process counterproductive. Using these lessons we devise processing conditions which prevent percolation of the adsorbed solvent vapor molecules for extended periods, thus extending the benefits of solvent vapor annealing and improving carrier mobility by nearly two orders of magnitude. Ultimately, it is demonstrated that QCM-D is a very powerful sensor of the state of the adsorbed solvent as well as the thin film, thus making it suitable for process development as well as in-line process monitoring both in laboratory and in future manufacturing settings. © 2013 American Chemical Society.

  8. Solvent vapor annealing in the molecular regime drastically improves carrier transport in small-molecule thin-film transistors

    KAUST Repository

    Khan, Hadayat Ullah; Li, Ruipeng; Ren, Yi; Chen, Long; Payne, Marcia M.; Bhansali, Unnat Sampatraj; Smilgies, Detlef Matthias; Anthony, John Edward; Amassian, Aram

    2013-01-01

    We demonstrate a new way to investigate and control the solvent vapor annealing of solution-cast organic semiconductor thin films. Solvent vapor annealing of spin-cast films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) is investigated in situ using quartz crystal microbalance with dissipation (QCM-D) capability, allowing us to monitor both solvent mass uptake and changes in the mechanical rigidity of the film. Using time-resolved grazing incidence wide angle X-ray scattering (GIWAXS) and complementary static atomic force microscopy (AFM), we demonstrate that solvent vapor annealing in the molecular regime can cause significant performance improvements in organic thin film transistors (OTFTs), whereas allowing the solvent to percolate and form a liquid phase results in catastrophic reorganization and dewetting of the film, making the process counterproductive. Using these lessons we devise processing conditions which prevent percolation of the adsorbed solvent vapor molecules for extended periods, thus extending the benefits of solvent vapor annealing and improving carrier mobility by nearly two orders of magnitude. Ultimately, it is demonstrated that QCM-D is a very powerful sensor of the state of the adsorbed solvent as well as the thin film, thus making it suitable for process development as well as in-line process monitoring both in laboratory and in future manufacturing settings. © 2013 American Chemical Society.

  9. Magnetorheological Damper Working in Squeeze Mode

    Directory of Open Access Journals (Sweden)

    Xinglong Gong

    2014-05-01

    Full Text Available This research is focused on evaluation of the magnetorheological fluids (MRFs based damper which works in squeeze mode. The operation direction of this damper is parallel to the direction of the external magnetic field. Before testing, commercial software ANSYS was used to analyze the magnetic field distribution inside the damper generated by charging current in the coil. The performance of the damper was tested by using the MTS809 (produced by MTS Systems Corporation, USA. For simulation of this damper, a mathematical model was set up. Experimental results showed that the small squeezed MR damper could produce large damping force; for example, the maximum damping force is nearly 6 kN, while the amplitude is 1.2 mm, the frequency is 1.0 Hz, and the current is 2.0 A, and the damping force was controllable by changing the current in the coil. The damping force versus displacement curves are complex. We divide them into four regions for simulation. The maximum damper force increased quickly with the increasing of the current in coil. This kind of damper can be used in vibration isolation for precise equipment.

  10. Study of the charge transport characteristics of dendrimer molecular thin films

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.C., E-mail: jcli@mail.neu.edu.cn; Han, N.; Wang, S.S.; Ba, D.C.

    2011-05-31

    In this work, we systematically studied the electrical characteristics of two types of dendritic arylamine thin film devices. We observed that, for devices with different interfacial structures, their charge injection barriers and transport properties are obviously different. The smallest charge injection barrier is observed in dendrimer devices without charge-transfer interfacial layers. The Richardson-Schottky thermionic emission model can be well used to fit the experimental current-voltage characteristics at a lower voltage region. The charge injection barrier increases about 0.4 eV and 0.5 eV when a 1-decanethiol self-assembly layer and -CN terminated dendrimer thin films are inserted as the interfacial layer, respectively. It is shown that the molecule/electrode charge-transfer interfaces can largely affect the device charge injection/transport process and consequently change the device performance. In this case, the space charge limited conduction theory is more applicable to simulate the device conduction mechanism. Owing to its ultra-thin thickness, the self-assembly monolayer technique is proved to be an efficient approach in engineering the interfacial electronic structures of dendrimer thin film devices.

  11. Study of the charge transport characteristics of dendrimer molecular thin films

    International Nuclear Information System (INIS)

    Li, J.C.; Han, N.; Wang, S.S.; Ba, D.C.

    2011-01-01

    In this work, we systematically studied the electrical characteristics of two types of dendritic arylamine thin film devices. We observed that, for devices with different interfacial structures, their charge injection barriers and transport properties are obviously different. The smallest charge injection barrier is observed in dendrimer devices without charge-transfer interfacial layers. The Richardson-Schottky thermionic emission model can be well used to fit the experimental current-voltage characteristics at a lower voltage region. The charge injection barrier increases about 0.4 eV and 0.5 eV when a 1-decanethiol self-assembly layer and -CN terminated dendrimer thin films are inserted as the interfacial layer, respectively. It is shown that the molecule/electrode charge-transfer interfaces can largely affect the device charge injection/transport process and consequently change the device performance. In this case, the space charge limited conduction theory is more applicable to simulate the device conduction mechanism. Owing to its ultra-thin thickness, the self-assembly monolayer technique is proved to be an efficient approach in engineering the interfacial electronic structures of dendrimer thin film devices.

  12. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, K.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (≤5 wt%) and not too low spin speeds

  13. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

  14. Modeling of metal thin film growth: Linking angstrom-scale molecular dynamics results to micron-scale film topographies

    Science.gov (United States)

    Hansen, U.; Rodgers, S.; Jensen, K. F.

    2000-07-01

    A general method for modeling ionized physical vapor deposition is presented. As an example, the method is applied to growth of an aluminum film in the presence of an ionized argon flux. Molecular dynamics techniques are used to examine the surface adsorption, reflection, and sputter reactions taking place during ionized physical vapor deposition. We predict their relative probabilities and discuss their dependence on energy and incident angle. Subsequently, we combine the information obtained from molecular dynamics with a line of sight transport model in a two-dimensional feature, incorporating all effects of reemission and resputtering. This provides a complete growth rate model that allows inclusion of energy- and angular-dependent reaction rates. Finally, a level-set approach is used to describe the morphology of the growing film. We thus arrive at a computationally highly efficient and accurate scheme to model the growth of thin films. We demonstrate the capabilities of the model predicting the major differences on Al film topographies between conventional and ionized sputter deposition techniques studying thin film growth under ionized physical vapor deposition conditions with different Ar fluxes.

  15. Molecular plating of thin lanthanide layers with improved material properties for nuclear applications

    International Nuclear Information System (INIS)

    Vascon, Alessio

    2013-01-01

    This work describes experiments to gain an improved understanding of the processes associated with the electrochemical production of thin lanthanide layers for nuclear science investigations, i.e., nuclear targets. Nd, Sm, and Gd layers were prepared by means of the so-called molecular plating (MP) technique, where electrodeposition from an organic medium is usually performed in the constant current mode using two-electrode cells. The obtained results allowed the identification of optimized production conditions, which led to a significantly improved layer quality. Constant current density MP is a mass-transport controlled process. The applied current is maintained constant by constant fluxes of electroactive species towards the cathode - where the layer is grown - and the anode. The investigations showed the cell potentials of the electrodeposition systems to be always dominated by the ohmic drop produced by the resistance of the solutions used for the studies. This allowed to derive an expression relating cell potential with concentration of the electroactive species. This expression is able to explain the trends recorded with different electrolyte concentrations and it serves as a basis to get towards a full understanding of the reasons leading to the characteristic minima observed in the evolution of the cell potential curves with time. The minima were found to correspond to an almost complete depletion of the Nd ions obtained by dissolution of the model salt used for the investigations. Nd was confirmed to be deposited at the cathode as derivatives of Nd 3+ - possibly as carboxylate, oxide or hydroxide. This fact was interpreted on the basis of the highly negative values of the standard redox potentials typical for lanthanide cations. Among the different electroactive species present in the complex MP solutions, the Nd 3+ ions were found to contribute to less than 20% to the total current. Because of electrolysis, also the mixed solvent contributed to the

  16. In vitro studies of PEG thin films with different molecular weights deposited by MAPLE

    DEFF Research Database (Denmark)

    Paun, Irina Alexandra; Ion, Valentin; Luculescu, Catalin-Romeo

    2012-01-01

    and their behavior in vitro. Thus, immersion in PBS induced swelling of the PEG films, which was more pronounced for PEG polymers of higher molecular weight. Prior to immersion in PBS, the PEG films of higher molecular weight were more hydrophilic, the water contact angles decreasing from ∼66 grd for PEG400 to ∼41...

  17. Bistetracene Thin Film Polymorphic Control to Unravel the Effect of Molecular Packing on Charge Transport

    KAUST Repository

    Burnett, Edmund K.

    2018-02-26

    Polymorphism, the ability for a given material to adopt multiple crystalline packing states, is a powerful approach for investigating how changes in molecular packing influence charge transport within organic semiconductors. In this study, a new

  18. Bistetracene Thin Film Polymorphic Control to Unravel the Effect of Molecular Packing on Charge Transport

    KAUST Repository

    Burnett, Edmund K.; Ly, Jack; Niazi, Muhammad Rizwan; Zhang, Lei; McCuskey, Samantha R.; Amassian, Aram; Smilgies, Detlef-M.; Mannsfeld, Stefan C. B.; Briseno, Alejandro L.

    2018-01-01

    Polymorphism, the ability for a given material to adopt multiple crystalline packing states, is a powerful approach for investigating how changes in molecular packing influence charge transport within organic semiconductors. In this study, a new

  19. A comprehensive field and laboratory study of scale control and scale squeezes in Sumatra, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Oddo, J.E.; Reizer, J.M.; Sitz, C.D. [Champion Technologies, Inc., Houston, TX (United States); Setia, D.E.A. [FMT Production Duri P.T. Caltex Pacific Indonesia (Indonesia); Hinrichsen, C.J. [Texaco Panama, Bellaire, TX (United States); Sujana, W. [P.T. Champion Kumia Djaja Technologies, Jakarta (Indonesia)

    1999-11-01

    Scale squeezes were performed on thirteen wells in the Duri Field, Sumatra. At the time the squeezes were completed, seven were designed to be `Acid Squeezes` and six were designed to be `Neutral Squeezes.` In the course of preparing for the scale squeezes, produced waters were collected and analyzed. In addition, scale inhibitor evaluations, and inhibitor compatibility studies were completed. Simulated squeezes were done in the laboratory to predict field performance. The methodologies and results of the background work are reported. In addition, the relative effectiveness of the two sets of squeezes is discussed. The inhibitor flowback concentrations alter the squeezes, in all cases, can be explained using speciation chemistry and the amorphous and crystalline phase solubilities of the inhibitor used. The wells squeezed with a more acidic inhibitor have more predictable and uniform inhibitor return concentration curves than the wells squeezed with a more neutral scale inhibitor.

  20. Phenomenology of the squeezed hadronic correlations at RHIC energies

    International Nuclear Information System (INIS)

    Padula, Sandra S.; Dudek, Danuce M.; Socolowski, Otavio Jr.

    2012-01-01

    We briefly review the basic theoretical results on bosonic back-to-back correlations (bBBC) and compare our predictions with the first experimental search for squeezed correlations of K + K - pairs, performed by PHENIX. The hadronic squeezed correlations are very sensitive to the functional form of the time emission distribution. The comparison is made for three different kaon time distributions. From such comparison we show that the outcome of the experimental search may still be inconclusive but it does not exclude the existence of squeezing effects on hadrons with in-medium modified masses already at RHIC energies. (author)

  1. Squeezing in an injection-locked semiconductor laser

    Science.gov (United States)

    Inoue, S.; Machida, S.; Yamamoto, Y.; Ohzu, H.

    1993-09-01

    The intensity-noise properties of an injection-locked semiconductor laser were studied experimentally. The constant-current-driven semiconductor laser producing the amplitude-squeezed state whose intensity noise was reduced below the standard quantum limit (SQL) by 0.72 dB was injection-locked by an external master laser. The measured intensity-noise level of the injection-locked semiconductor laser was 0.91 dB below the SQL. This experimental result indicates that a phase-coherent amplitude-squeezed state or squeezed vacuum state together with a reference local oscillator wave can be generated directly by semiconductor laser systems.

  2. Optimal Operation of a Josephson Parametric Amplifier for Vacuum Squeezing

    Science.gov (United States)

    Malnou, M.; Palken, D. A.; Vale, Leila R.; Hilton, Gene C.; Lehnert, K. W.

    2018-04-01

    A Josephson parametric amplifier (JPA) can create squeezed states of microwave light, lowering the noise associated with certain quantum measurements. We experimentally study how the JPA's pump influences the phase-sensitive amplification and deamplification of a coherent tone's amplitude when that amplitude is commensurate with vacuum fluctuations. We predict and demonstrate that, by operating the JPA with a single current pump whose power is greater than the value that maximizes gain, the amplifier distortion is reduced and, consequently, squeezing is improved. Optimizing the singly pumped JPA's operation in this fashion, we directly observe 3.87 ±0.03 dB of vacuum squeezing over a bandwidth of 30 MHz.

  3. Anomalous Quantum Correlations of Squeezed Light

    Science.gov (United States)

    Kühn, B.; Vogel, W.; Mraz, M.; Köhnke, S.; Hage, B.

    2017-04-01

    Three different noise moments of field strength, intensity, and their correlations are simultaneously measured. For this purpose a homodyne cross-correlation measurement [1] is implemented by superimposing the signal field and a weak local oscillator on an unbalanced beam splitter. The relevant information is obtained via the intensity noise correlation of the output modes. Detection details like quantum efficiencies or uncorrelated dark noise are meaningless for our technique. Yet unknown insight in the quantumness of a squeezed signal field is retrieved from the anomalous moment, correlating field strength with intensity noise. A classical inequality including this moment is violated for almost all signal phases. Precognition on quantum theory is superfluous, as our analysis is solely based on classical physics.

  4. Effect of native oxide layers on copper thin-film tensile properties: A reactive molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Skarlinski, Michael D., E-mail: michael.skarlinski@rochester.edu [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Quesnel, David J. [Materials Science Program, University of Rochester, Rochester, New York 14627 (United States); Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2015-12-21

    Metal-oxide layers are likely to be present on metallic nano-structures due to either environmental exposure during use, or high temperature processing techniques such as annealing. It is well known that nano-structured metals have vastly different mechanical properties from bulk metals; however, difficulties in modeling the transition between metallic and ionic bonding have prevented the computational investigation of the effects of oxide surface layers. Newly developed charge-optimized many body [Liang et al., Mater. Sci. Eng., R 74, 255 (2013)] potentials are used to perform fully reactive molecular dynamics simulations which elucidate the effects that metal-oxide layers have on the mechanical properties of a copper thin-film. Simulated tensile tests are performed on thin-films while using different strain-rates, temperatures, and oxide thicknesses to evaluate changes in yield stress, modulus, and failure mechanisms. Findings indicate that copper-thin film mechanical properties are strongly affected by native oxide layers. The formed oxide layers have an amorphous structure with lower Cu-O bond-densities than bulk CuO, and a mixture of Cu{sub 2}O and CuO charge character. It is found that oxidation will cause modifications to the strain response of the elastic modulii, producing a stiffened modulii at low temperatures (<75 K) and low strain values (<5%), and a softened modulii at higher temperatures. While under strain, structural reorganization within the oxide layers facilitates brittle yielding through nucleation of defects across the oxide/metal interface. The oxide-free copper thin-film yielding mechanism is found to be a tensile-axis reorientation and grain creation. The oxide layers change the observed yielding mechanism, allowing for the inner copper thin-film to sustain an FCC-to-BCC transition during yielding. The mechanical properties are fit to a thermodynamic model based on classical nucleation theory. The fit implies that the oxidation of the

  5. EDITORIAL: Squeeze transformation and optics after Einstein

    Science.gov (United States)

    Kim, Young S.; Man'ko, Margarita A.; Planat, Michel

    2005-12-01

    With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besançon, France, 2-6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458-S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo

  6. Effects of magnetic flux densities on microstructure evolution and magnetic properties of molecular-beam-vapor-deposited nanocrystalline Fe_3_0Ni_7_0 thin films

    International Nuclear Information System (INIS)

    Cao, Yongze; Wang, Qiang; Li, Guojian; Ma, Yonghui; Du, Jiaojiao; He, Jicheng

    2015-01-01

    Nanocrystalline Fe_3_0Ni_7_0 (in atomic %) thin films were prepared by molecular-beam-vapor deposition in magnetic fields with different magnetic flux densities. The microstructure evolution of these thin films was studied by atomic force microscopy, transmission electron microscopy, and high resolution transmission electron microscopy; the soft magnetic properties were examined by vibrating sample magnetometer at room temperature. The results show that all our Fe_3_0Ni_7_0 thin films feature an fcc single-phase structure. With increasing magnetic flux density, surface roughness, average particle size and grain size of the thin films decreased, and the short-range ordered clusters (embryos) of thin films increased. Additionally, the magnetic anisotropy in the in-plane and the coercive forces of the thin films gradually reduced with increasing magnetic flux density. - Highlights: • With increasing magnetic flux density, average particle size of films decreased. • With increasing magnetic flux density, surface roughness of thin films decreased. • With increasing magnetic flux density, short-range ordered clusters increased. • With increasing magnetic flux density, the coercive forces of thin films reduced. • With increasing magnetic flux density, soft magnetic properties are improved.

  7. Brilliant molecular nanocrystals emerging from sol-gel thin films: towards a new generation of fluorescent biochips

    International Nuclear Information System (INIS)

    Dubuisson, E; Monnier, V; Sanz-Menez, N; Ibanez, A; Boury, B; Usson, Y; Pansu, R B

    2009-01-01

    To develop highly sensitive biosensors, we made directly available to biological aqueous solutions organic nanocrystals previously grown in the pores of sol-gel films. Through the controlled dissolution of the sol-gel surface, we obtained emerging nanocrystals that remained strongly anchored to the sol-gel coating for good mechanical stability of the final sensing device. We demonstrated that in the presence of a solution of DNA functionalized with a molecular probe, the nanocrystal fluorescence is strongly quenched by Foerster resonance energy transfer thus opening the way towards very sensitive fluorescent biosensors through biomolecules grafted onto fluorescent nanocrystals. Finally, this controlled dissolution, involving weak concentrated NaOH solution, is a generic process that can be used for the thinning of any kind of sol-gel layer.

  8. Molecular dynamics modeling on the role of initial void geometry in a thin aluminum film under uniaxial tension

    International Nuclear Information System (INIS)

    Cui, Yi; Chen, Zengtao

    2015-01-01

    The effect of initial void geometry on damage progression in a thin aluminum film under uniaxial load is studied via molecular dynamics (MD) method. The embedded voids are with different initial geometries regarding shape, porosity and intervoid ligament distance (ILD). Major simulations are run upon twelve MD geometries with each containing 8–27 million atoms. The corresponding stress–strain relation is monitored during the microstructure evolution of the specimens. The critical stress to trigger the dislocation emission is found in line with the prediction of the Lubarda model. The simulation results reveal that the initial void geometry has substantial impact on the stress–strain relation especially for a specimen with larger initial porosity. (paper)

  9. Coherent light squeezing states within a modified microring system

    Science.gov (United States)

    Ali, J.; Pornsuwancharoen, N.; Youplao, P.; Aziz, M. S.; Amiri, I. S.; Chaiwong, K.; Chiangga, S.; Singh, G.; Yupapin, P.

    2018-06-01

    We have proposed the simple method of the squeezed light generation in the modified microring resonator, which is known as the microring conjugate mirror (MCM). When the monochromatic light is input into the MCM, the general form of the squeezed coherent states for a quantum harmonic oscillator can be generated by controlling the additional two side rings, which are the phase modulators. By using the graphical method called the Optiwave program, the coherent squeezed states of coherent light within an MCM can be obtained and interpreted as the amplitude, phase, quadrature and photon number-squeezed states. This method has shown potentials for microring related device design, which can be used before practical applications.

  10. Phonon squeezed states: quantum noise reduction in solids

    Science.gov (United States)

    Hu, Xuedong; Nori, Franco

    1999-03-01

    This article discusses quantum fluctuation properties of a crystal lattice, and in particular, phonon squeezed states. Squeezed states of phonons allow a reduction in the quantum fluctuations of the atomic displacements to below the zero-point quantum noise level of coherent phonon states. Here we discuss our studies of both continuous-wave and impulsive second-order Raman scattering mechanisms. The later approach was used to experimentally suppress (by one part in a million) fluctuations in phonons. We calculate the expectation values and fluctuations of both the atomic displacement and the lattice amplitude operators, as well as the effects of the phonon squeezed states on macroscopically measurable quantities, such as changes in the dielectric constant. These results are compared with recent experiments. Further information, including preprints and animations, are available in http://www-personal.engin.umich.edu/∼nori/squeezed.html.

  11. Squeezed Phonons: Modulating Quantum Fluctuations of Atomic Displacements.

    Science.gov (United States)

    Hu, Xuedong; Nori, Franco

    1997-03-01

    We have studied phonon squeezed states and also put forward several proposals for their generation(On phonon parametric process, X. Hu and F. Nori, Phys. Rev. Lett. 76), 2294 (1996); on polariton mechanism, X. Hu and F. Nori, Phys. Rev. B 53, 2419 (1996); on second-order Raman scattering, X. Hu and F. Nori, preprint.. Here, we compare the relative merits and limitations of these approaches, including several factors that will limit the amount of phonon squeezing. In particular, we investigate the effect of the initial thermal states on the phonon modes. Using a model for the phonon density matrix, we also study the mixing of the phonon squeezed states with thermal states, which describes the decay of the phonon coherence. Finally, we calculate the maximum possible squeezing from a phonon parametric process limited by phonon decay.

  12. Price squeezes in electric power: The new Battle of Concord

    International Nuclear Information System (INIS)

    Kwoka, J.E. Jr.

    1992-01-01

    The US Court of Appeals opinion in Town of Concord v. Boston Edison offers a vigorous statement of the position that in a regulated market, what may appear to be a price squeeze almost certainly cannot harm the competitive process and therefore should not be held to violate the antitrust laws. While not disputing the possibility of self-serving claims of price squeezes, this article shows that truly anticompetitive price squeezes may indeed occur in the electric power industry and cannot be so readily dismissed. This analysis begins with a brief factual and economic background on price squeezes, then addresses arguments made in Concord and elsewhere seeking to disprove their possibility, and demonstrate that sound economics and good policy require a more balanced approach

  13. Squeezing in multi-mode nonlinear optical state truncation

    International Nuclear Information System (INIS)

    Said, R.S.; Wahiddin, M.R.B.; Umarov, B.A.

    2007-01-01

    In this Letter, we show that multi-mode qubit states produced via nonlinear optical state truncation driven by classical external pumpings exhibit squeezing condition. We restrict our discussions to the two- and three-mode cases

  14. Coherent light squeezing states within a modified microring system

    Directory of Open Access Journals (Sweden)

    J. Ali

    2018-06-01

    Full Text Available We have proposed the simple method of the squeezed light generation in the modified microring resonator, which is known as the microring conjugate mirror (MCM. When the monochromatic light is input into the MCM, the general form of the squeezed coherent states for a quantum harmonic oscillator can be generated by controlling the additional two side rings, which are the phase modulators. By using the graphical method called the Optiwave program, the coherent squeezed states of coherent light within an MCM can be obtained and interpreted as the amplitude, phase, quadrature and photon number-squeezed states. This method has shown potentials for microring related device design, which can be used before practical applications.

  15. Squeeze-film damping characteristics of cantilever microresonators ...

    African Journals Online (AJOL)

    user

    perturbation approach does not apply to cantilever plates because of ...... Direct coupling of electrostatic and structural domain has been achieved using ... forces are computed to obtain the modal squeeze stiffness and damping parameters.

  16. Engineering of an ultra-thin molecular superconductor by charge transfer

    Science.gov (United States)

    Hla, Saw Wai; Hassanien, Abdelrahim; Kendal, Clark

    2016-06-07

    A method of forming a superconductive device of a single layer of (BETS).sub.2GaCl.sub.4 molecules on a substrate surface which displays a superconducting gap that increases exponentially with the length of the molecular chain is provided.

  17. Wigner function and tomogram of the excited squeezed vacuum state

    International Nuclear Information System (INIS)

    Meng Xiangguo; Wang Jisuo; Fan Hongyi

    2007-01-01

    The excited squeezed light (ESL) can be the outcome of interaction between squeezed light probe and excited atom, which can explore the status and the structure of the atom. We calculate the Wigner function and tomogram of ESL that may be comparable to the experimental measurement of quadrature-amplitude distribution for the light field obtained using balanced homodyne detection. The method of calculation seems new

  18. Wigner function and tomogram of the excited squeezed vacuum state

    Energy Technology Data Exchange (ETDEWEB)

    Meng Xiangguo [Department of Physics, Liaocheng University, Shandong Province 252059 (China); Wang Jisuo [Department of Physics, Liaocheng University, Shandong Province 252059 (China)]. E-mail: jswang@lcu.edu.cn; Fan Hongyi [Department of Physics, Liaocheng University, Shandong Province 252059 (China); CCAST (World Laboratory), P.O. Box 8730, 100080 Beijing (China)

    2007-01-29

    The excited squeezed light (ESL) can be the outcome of interaction between squeezed light probe and excited atom, which can explore the status and the structure of the atom. We calculate the Wigner function and tomogram of ESL that may be comparable to the experimental measurement of quadrature-amplitude distribution for the light field obtained using balanced homodyne detection. The method of calculation seems new.

  19. Understanding squeezing of quantum states with the Wigner function

    Science.gov (United States)

    Royer, Antoine

    1994-01-01

    The Wigner function is argued to be the only natural phase space function evolving classically under quadratic Hamiltonians with time-dependent bilinear part. This is used to understand graphically how certain quadratic time-dependent Hamiltonians induce squeezing of quantum states. The Wigner representation is also used to generalize Ehrenfest's theorem to the quantum uncertainties. This makes it possible to deduce features of the quantum evolution, such as squeezing, from the classical evolution, whatever the Hamiltonian.

  20. Density-dependent squeezing of excitons in highly excited semiconductors

    International Nuclear Information System (INIS)

    Nguyen Hong Quang.

    1995-07-01

    The time evolution from coherent states to squeezed states of high density excitons is studied theoretically based on the boson formalism and within the Random Phase Approximation. Both the mutual interaction between excitons and the anharmonic exciton-photon interaction due to phase-space filling of excitons are taken into account. It is shown that the exciton squeezing depends strongly on the exciton density in semiconductors and becomes smaller with increasing the latter. (author). 16 refs, 2 figs

  1. Squeezing of thermal and quantum fluctuations: Universal features

    DEFF Research Database (Denmark)

    Svensmark, Henrik; Flensberg, Karsten

    1993-01-01

    We study the classical and quantum fluctuations of a general damped forced oscillator close to a bifurcation instability. Near the instability point, the fluctuations are strongly phase correlated and are squeezed. In the limit of low damping, it is shown that the system has universal features when...... scaled with the damping. The same scaling law applies to the classical and to the quantum regimes. We furthermore show that the coupling to the environment is crucial in the generation of squeezed fluctuations....

  2. Resonance fluorescence from an atom in a squeezed vacuum

    Science.gov (United States)

    Carmichael, H. J.; Lane, A. S.; Walls, D. F.

    1987-06-01

    The fluorescent spectrum for a two-level atom which is damped by a squeezed vacuum shows striking differences from the spectrum for ordinary resonance fluorescence. For strong coherent driving fields the Mollow triplet depends on the relative phase of the driving field and the squeezed vacuum field. The central peak may have either subnatural linewidth or supernatural linewidth depending on this phase. The mean atomic polarization also shows a phase sensitivity.

  3. Spin squeezing and light entanglement in Coherent Population Trapping

    DEFF Research Database (Denmark)

    Dantan, Aurelien Romain; Cviklinski, Jean; Giacobino, Elisabeth

    2006-01-01

    We show that strong squeezing and entanglement can be generated at the output of a cavity containing atoms interacting with two fields in a coherent population trapping situation, on account of a nonlinear Faraday effect experienced by the fields close to a dark-state resonance in a cavity....... Moreover, the cavity provides a feedback mechanism allowing to reduce the quantum fluctuations of the ground state spin, resulting in strong steady state spin squeezing....

  4. Squeezed condensate and confinement in a scalar model

    International Nuclear Information System (INIS)

    Blaschke, D.; Pavel, H.P.; Roepke, G.; Peradze, G.; Pervushin, V.N.

    1996-01-01

    The generating functional of a free scalar field theory is generalized to the case of a squeezed vacuum. The squeezed vacuum is prepared by macroscopically populating the original vacuum with pairs of zero energy particles. It is shown that the corresponding quark propagator has no poles on the real-k 2 axis which can be interpreted as quark confinement. In contrast, a scalar meson-like bound state exists as solution of the corresponding Bethe-Salpeter equation. 20 refs

  5. Teleportation of squeezing: Optimization using non-Gaussian resources

    Science.gov (United States)

    Dell'Anno, Fabio; de Siena, Silvio; Adesso, Gerardo; Illuminati, Fabrizio

    2010-12-01

    We study the continuous-variable quantum teleportation of states, statistical moments of observables, and scale parameters such as squeezing. We investigate the problem both in ideal and imperfect Vaidman-Braunstein-Kimble protocol setups. We show how the teleportation fidelity is maximized and the difference between output and input variances is minimized by using suitably optimized entangled resources. Specifically, we consider the teleportation of coherent squeezed states, exploiting squeezed Bell states as entangled resources. This class of non-Gaussian states, introduced by Illuminati and co-workers [F. Dell’Anno, S. De Siena, L. Albano, and F. Illuminati, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.76.022301 76, 022301 (2007); F. Dell’Anno, S. De Siena, and F. Illuminati, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.81.012333 81, 012333 (2010)], includes photon-added and photon-subtracted squeezed states as special cases. At variance with the case of entangled Gaussian resources, the use of entangled non-Gaussian squeezed Bell resources allows one to choose different optimization procedures that lead to inequivalent results. Performing two independent optimization procedures, one can either maximize the state teleportation fidelity, or minimize the difference between input and output quadrature variances. The two different procedures are compared depending on the degrees of displacement and squeezing of the input states and on the working conditions in ideal and nonideal setups.

  6. Teleportation of squeezing: Optimization using non-Gaussian resources

    International Nuclear Information System (INIS)

    Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio; Adesso, Gerardo

    2010-01-01

    We study the continuous-variable quantum teleportation of states, statistical moments of observables, and scale parameters such as squeezing. We investigate the problem both in ideal and imperfect Vaidman-Braunstein-Kimble protocol setups. We show how the teleportation fidelity is maximized and the difference between output and input variances is minimized by using suitably optimized entangled resources. Specifically, we consider the teleportation of coherent squeezed states, exploiting squeezed Bell states as entangled resources. This class of non-Gaussian states, introduced by Illuminati and co-workers [F. Dell'Anno, S. De Siena, L. Albano, and F. Illuminati, Phys. Rev. A 76, 022301 (2007); F. Dell'Anno, S. De Siena, and F. Illuminati, ibid. 81, 012333 (2010)], includes photon-added and photon-subtracted squeezed states as special cases. At variance with the case of entangled Gaussian resources, the use of entangled non-Gaussian squeezed Bell resources allows one to choose different optimization procedures that lead to inequivalent results. Performing two independent optimization procedures, one can either maximize the state teleportation fidelity, or minimize the difference between input and output quadrature variances. The two different procedures are compared depending on the degrees of displacement and squeezing of the input states and on the working conditions in ideal and nonideal setups.

  7. Fifth International Conference on Squeezed States and Uncertainty Relations

    Science.gov (United States)

    Han, D. (Editor); Janszky, J. (Editor); Kim, Y. S. (Editor); Man'ko, V. I. (Editor)

    1998-01-01

    The Fifth International Conference on Squeezed States and Uncertainty Relations was held at Balatonfured, Hungary, on 27-31 May 1997. This series was initiated in 1991 at the College Park Campus of the University of Maryland as the Workshop on Squeezed States and Uncertainty Relations. The scientific purpose of this series was to discuss squeezed states of light, but in recent years the scope is becoming broad enough to include studies of uncertainty relations and squeeze transformations in all branches of physics including quantum optics and foundations of quantum mechanics. Quantum optics will continue playing the pivotal role in the future, but the future meetings will include all branches of physics where squeeze transformations are basic. As the meeting attracted more participants and started covering more diversified subjects, the fourth meeting was called an international conference. The Fourth International Conference on Squeezed States and Uncertainty Relations was held in 1995 was hosted by Shanxi University in Taiyuan, China. The fifth meeting of this series, which was held at Balatonfured, Hungary, was also supported by the IUPAP. In 1999, the Sixth International Conference will be hosted by the University of Naples in 1999. The meeting will take place in Ravello near Naples.

  8. Stratification-induced order--disorder phase transitions in molecularly thin confined films

    International Nuclear Information System (INIS)

    Schoen, M.; Diestler, D.J.; Cushman, J.H.

    1994-01-01

    By means of grand canonical ensemble Monte Carlo simulations of a monatomic film confined between unstructured (i.e., molecularly smooth) rigidly fixed solid surfaces (i.e., walls), we investigate the mechanism of molecular stratification, i.e., the tendency of atoms to arrange themselves in layers parallel with the walls. Stratification is accompanied by a heretofore unnoticed order--disorder phase transition manifested as a maximum in density fluctuations at the transition point. The transition involves phases with different transverse packing characteristics, although the number of layers accommodated between the walls remains unchanged during the transition, which occurs periodically as the film thickens. However, with increasing thickness, an increasingly smaller proportion of the film is structurally affected by the transition. Thus, the associated maximum in density fluctuations diminishes rapidly with film thickness

  9. Nanotexture Optimization by Oxygen Plasma of Mesoporous Silica Thin Film for Enrichment of Low Molecular Weight Peptides Captured from Human Serum

    Science.gov (United States)

    Hu, Ye; Peng, Yang; Brousseau, Louis; Bouamrani, Ali; Liu, Xuewu; Ferrari, Mauro

    2010-01-01

    This study investigated the optimization of mesoporous silica thin films by nanotexturing using oxygen plasma versus thermal oxidation. Calcination in oxygen plasma provides superior control over pore formation with regard to the pore surface and higher fidelity to the structure of the polymer template. The resulting porous film offers an ideal substrate for the selective partitioning of peptides from complex mixtures. The improved chemico-physical characteristics of porous thin films (pore size distribution, nanostructure, surface properties and pore connectivity) were systematically characterized with XRD, Ellipsometry, FTIR, TEM and N2 adsorption/desorption. The enrichment of low molecular weight proteins captured from human serum on mesoporous silica thin films fabricated by both methodologies were investigated by comparison of their MALDI-TOF MS profiles. This novel on-chip fractionation technology offers advantages in recovering the low molecular weight peptides from human serum, which has been recognized as an informative resource for early diagnosis of cancer and other diseases. PMID:21179395

  10. Effectiveness of the squeezing out and final squeezing out of petroleum of an increased viscosity by alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Begnazarov, T.

    1979-01-01

    The remaining petroleum in the flooded zone is determined by the ratio of viscosity forces to the forces of the surface tension, which are expressed by the coefficient Ka. With this, for each kind of porous medium, there exists a natural cricial value Ka. For the purpose of studying the effect of the given parameters on the value of the remaining petroleum, experiments were carried out on artificial specimens. In the tests, using petroleum of the Mishkin deposit, the surface tension on the boundary of the petroleum with the distilled water and alkaline solutions were respectively equal to 37.1 and 1.33 dynes per centimeter. The experiments showed, that the squeezing out of the petroleum with water or alkaline solutions leads to similar results. This means, that the composite parameter Ka does not affect the value of the remaining petroleum saturation. The effectiveness of the final squeezing out of the petroleum of increased viscosity was also studied. These experiments were carried out in two variations of the injection of the squeezed out agent: in the first variation, the petroleum was squeezed out with water in the first stage, and in the second stage it was squeezed out by an alkaline solution, and in the subsequent stages, a change in the squeezing out agent took place. By finishing the first stage, the attained values of the coefficients of the squeezing out were practically similar (0.72). In the second stage, the final squeezing out of the petroleum with a solution of alkaline, provided a major effect.

  11. Molecular dynamics study on the effect of boundary heating rate on the phase change characteristics of thin film liquid

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mohammad Nasim, E-mail: nasim@me.buet.ac.bd.com; Morshed, A. K. M. Monjur, E-mail: shavik@me.buet.ac.bd.com; Rabbi, Kazi Fazle, E-mail: rabbi35.me10@gmail.com; Haque, Mominul, E-mail: mominulmarup@gmail.com [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology (BUET) Dhaka-1000 (Bangladesh)

    2016-07-12

    In this study, theoretical investigation of thin film liquid phase change phenomena under different boundary heating rates has been conducted with the help of molecular dynamics simulation. To do this, the case of argon boiling over a platinum surface has been considered. The study has been conducted to get a better understanding of the nano-scale physics of evaporation/boiling for a three phase system with particular emphasis on the effect of boundary heating rate. The simulation domain consisted of liquid and vapor argon atoms placed over a platinum wall. Initially the whole system was brought to an equilibrium state at 90 K with the help of equilibrium molecular dynamics and then the temperature of the bottom wall was increased to a higher temperature (250 K/130 K) over a finite heating period. Depending on the heating period, the boundary heating rate has been varied in the range of 1600×10{sup 9} K/s to 8×10{sup 9} K/s. The variations of argon region temperature, pressure, net evaporation number with respect to time under different boundary heating rates have been determined and discussed. The heat fluxes normal to platinum wall for different cases were also calculated and compared with theoretical upper limit of maximum possible heat transfer to elucidate the effect of boundary heating rate.

  12. Thermally driven smoothening of molecular thin films: Structural transitions in n-alkane layers studied in real-time

    Energy Technology Data Exchange (ETDEWEB)

    Pithan, Linus; Weber, Christopher; Zykov, Anton; Sauer, Katrein; Opitz, Andreas; Kowarik, Stefan, E-mail: stefan.kowarik@physik.hu-berlin.de [Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Meister, Eduard; Brütting, Wolfgang [Institut für Physik, Universität Augsburg, 86135 Augsburg (Germany); Jin, Chenyu; Riegler, Hans [Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14476 Potsdam-Golm (Germany)

    2015-10-28

    We use thermal annealing to improve smoothness and to increase the lateral size of crystalline islands of n-tetratetracontane (TTC, C{sub 44}H{sub 90}) films. With in situ x-ray diffraction, we find an optimum temperature range leading to improved texture and crystallinity while avoiding an irreversible phase transition that reduces crystallinity again. We employ real-time optical phase contrast microscopy with sub-nm height resolution to track the diffusion of TTC across monomolecular step edges which causes the unusual smoothing of a molecular thin film during annealing. We show that the lateral island sizes increase by more than one order of magnitude from 0.5 μm to 10 μm. This desirable behavior of 2d-Ostwald ripening and smoothing is in contrast to many other organic molecular films where annealing leads to dewetting, roughening, and a pronounced 3d morphology. We rationalize the smoothing behavior with the highly anisotropic attachment energies and low surface energies for TTC. The results are technically relevant for the use of TTC as passivation layer and as gate dielectric in organic field effect transistors.

  13. Development of molecular precursors for deposition of indium sulphide thin film electrodes for photoelectrochemical applications.

    Science.gov (United States)

    Ehsan, Muhammad Ali; Peiris, T A Nirmal; Wijayantha, K G Upul; Olmstead, Marilyn M; Arifin, Zainudin; Mazhar, Muhammad; Lo, K M; McKee, Vickie

    2013-08-14

    Symmetrical and unsymmetrical dithiocarbamato pyridine solvated and non-solvated complexes of indium(III) with the general formula [In(S2CNRR')3]·n(py) [where py = pyridine; R,R' = Cy, n = 2 (1); R,R' = (i)Pr, n = 1.5 (2); NRR' = Pip, n = 0.5 (3) and R = Bz, R' = Me, n = 0 (4)] have been synthesized. The compositions, structures and properties of these complexes have been studied by means of microanalysis, IR and (1)H-NMR spectroscopy, X-ray single crystal and thermogravimetric (TG/DTG) analyses. The applicability of these complexes as single source precursors (SSPs) for the deposition of β-In2S3 thin films on fluorine-doped SnO2 (FTO) coated conducting glass substrates by aerosol-assisted chemical vapour deposition (AACVD) at temperatures of 300, 350 and 400 °C is studied. All films have been characterized by powder X-ray diffraction (PXRD) and energy dispersive X-ray analysis (EDX) for the detection of phase and stoichiometry of the deposit. Scanning electron microscopy (SEM) studies reveal that precursors (1)-(4), irrespective of different metal ligand design, generate comparable morphologies of β-In2S3 thin films at different temperatures. Direct band gap energies of 2.2 eV have been estimated from the UV-vis spectroscopy for the β-In2S3 films fabricated from precursors (1) and (4). The photoelectrochemical (PEC) properties of β-In2S3 were confirmed by recording the current-voltage plots under light and dark conditions. The plots showed anodic photocurrent densities of 1.25 and 0.65 mA cm(-2) at 0.23 V vs. Ag/AgCl for the β-In2S3 films made at 400 and 350 °C from the precursors (1) and (4), respectively. The photoelectrochemical performance indicates that the newly synthesised precursors are highly useful in fabricating β-In2S3 electrodes for solar energy harvesting and optoelectronic application.

  14. Growth of CrTe thin films by molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Sreenivasan, M.G.; Hou, X.J.; Teo, K.L.; Jalil, M.B.A.; Liew, T.; Chong, T.C.

    2006-01-01

    We report the growth of Cr 1-δ Te films on (100) GaAs substrates using ZnTe buffer layers by solid-source molecular-beam epitaxial technique. RHEED patterns indicate a clear structural change during the initial stages of deposition. Temperature-dependent magnetization results reveal that different NiAs-related phases of Cr 1-δ Te can be obtained at different substrate temperatures. By varying the film thickness, a metastable zinc blende structure of CrTe could be obtained at lower substrate temperature

  15. Origin of green luminescence in ZnO thin film grown by molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Heo, Y.W.; Norton, D.P.; Pearton, S.J.

    2005-01-01

    The properties of ZnO films grown by molecular-beam epitaxy are reported. The primary focus was on understanding the origin of deep-level luminescence. A shift in deep-level emission from green to yellow is observed with reduced Zn pressure during the growth. Photoluminescence and Hall measurements were employed to study correlations between deep-level/near-band-edge emission and carrier density. With these results, we suggest that the green emission is related to donor-deep acceptor (Zn vacancy V Zn - ) and the yellow to donor-deep acceptor (oxygen vacancy, O i - )

  16. Ultrasonic force microscopy: detection and imaging of ultra-thin molecular domains.

    Science.gov (United States)

    Dinelli, Franco; Albonetti, Cristiano; Kolosov, Oleg V

    2011-03-01

    The analysis of the formation of ultra-thin organic films is a very important issue. In fact, it is known that the properties of organic light emitting diodes and field effect transistors are strongly affected by the early growth stages. For instance, in the case of sexithiophene, the presence of domains made of molecules with the backbone parallel to the substrate surface has been indirectly evidenced by photoluminescence spectroscopy and confocal microscopy. On the contrary, conventional scanning force microscopy both in contact and intermittent contact modes have failed to detect such domains. In this paper, we show that Ultrasonic Force Microscopy (UFM), sensitive to nanomechanical properties, allows one to directly identify the structure of sub-monolayer thick films. Sexithiophene flat domains have been imaged for the first time with nanometer scale spatial resolution. A comparison with lateral force and intermittent contact modes has been carried out in order to explain the origins of the UFM contrast and its advantages. In particular, it indicates that UFM is highly suitable for investigations where high sensitivity to material properties, low specimen damage and high spatial resolution are required. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Squeezed noise in precision force measurements

    International Nuclear Information System (INIS)

    Bocko, M.F.; Bordoni, F.; Fuligni, F.; Johnson, W.W.

    1986-01-01

    The effort to build gravitational radiation antennae with sensitivity sufficient to detect bursts of radiation from supernovae in the Virgo cluster of galaxies has caused a consideration of the fundamental limits for the detection of weak forces. The existing Weber bar detectors will be eventually limited, by the phase insensitive transducers now used, to noise temperatures no better than that of the first amplifier which follows the transducer. Even for a quantum limited amplifier this may not give the sensitivity required to definitively detect gravitational radiation. In a 'back action evasion' measurement a specific phase sensitive transducer would be used. It is believed that by the technique of measuring one of the two antenna phases it is possible to reach an effective noise temperature for the measured phase which is far below the amplifier noise temperature. This is at the expense of an infinite noise temperature in the unmeasured antenna phase and is thus described as squeezing the noise. The authors outline the theoretical model for the behavior of such systems and present data from several experiments which demonstrate the main features of a back action evasion measurement. (Auth.)

  18. EDITORIAL: Squeezed states and uncertainty relations

    Science.gov (United States)

    Jauregue-Renaud, Rocio; Kim, Young S.; Man'ko, Margarita A.; Moya-Cessa, Hector

    2004-06-01

    This special issue of Journal of Optics B: Quantum and Semiclassical Optics is composed mainly of extended versions of talks and papers presented at the Eighth International Conference on Squeezed States and Uncertainty Relations held in Puebla, Mexico on 9-13 June 2003. The Conference was hosted by Instituto de Astrofísica, Óptica y Electrónica, and the Universidad Nacional Autónoma de México. This series of meetings began at the University of Maryland, College Park, USA, in March 1991. The second and third workshops were organized by the Lebedev Physical Institute in Moscow, Russia, in 1992 and by the University of Maryland Baltimore County, USA, in 1993, respectively. Afterwards, it was decided that the workshop series should be held every two years. Thus the fourth meeting took place at the University of Shanxi in China and was supported by the International Union of Pure and Applied Physics (IUPAP). The next three meetings in 1997, 1999 and 2001 were held in Lake Balatonfüred, Hungary, in Naples, Italy, and in Boston, USA, respectively. All of them were sponsored by IUPAP. The ninth workshop will take place in Besançon, France, in 2005. The conference has now become one of the major international meetings on quantum optics and the foundations of quantum mechanics, where most of the active research groups throughout the world present their new results. Accordingly this conference has been able to align itself to the current trend in quantum optics and quantum mechanics. The Puebla meeting covered most extensively the following areas: quantum measurements, quantum computing and information theory, trapped atoms and degenerate gases, and the generation and characterization of quantum states of light. The meeting also covered squeeze-like transformations in areas other than quantum optics, such as atomic physics, nuclear physics, statistical physics and relativity, as well as optical devices. There were many new participants at this meeting, particularly

  19. On the role of initial void geometry in plastic deformation of metallic thin films: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yanqing [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332-0340 (United States); Xu, Shuozhi, E-mail: shuozhixu@gatech.edu [GWW School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)

    2016-12-15

    Void growth is usually considered one of the most critical phases leading to dynamic fracture of ductile materials. Investigating the detailed process of void growth at the nanoscale aids in understanding the damage mechanism of metals. While most atomistic simulations by far assume circular or spherical voids for simplicity, recent studies highlight the significance of the initial void ellipticity in mechanical response of voided metals. In this work, we perform large scale molecular dynamics simulations with millions of atoms to investigate the void growth in plastic deformation of thin films in face-centered cubic Cu. It is found that the initial ellipticity and the initial orientation angle of the void have substantial impacts on the dislocation nucleation, the void evolution, and the stress-strain response. In particular, the initial dislocation emission sites and the sequence of slip plane activation vary with the initial void geometry. For the void size evolution, three regimes are identified: (I) the porosity increases relatively slowly in the absence of dislocations, (II) the porosity grows much more rapidly after dislocations start to glide on different slip planes, and (III) the rate of porosity variation becomes much more slowly when dislocations are saturated in the model, and the void surface becomes irregular, non-smooth. In terms of the stress-strain response, the effects of the initial orientation angle are more pronounced when the initial void ellipticity is large; the influence of the initial void ellipticity is different for different initial orientation angles. The effects of the temperature, the strain rate, the loading direction, and the initial porosity in the void growth are also explored. Our results reveal the underlying mechanisms of initial void geometry-dependent plastic deformation of metallic thin films and shed light on informing more accurate theoretical models.

  20. On the role of initial void geometry in plastic deformation of metallic thin films: A molecular dynamics study

    International Nuclear Information System (INIS)

    Su, Yanqing; Xu, Shuozhi

    2016-01-01

    Void growth is usually considered one of the most critical phases leading to dynamic fracture of ductile materials. Investigating the detailed process of void growth at the nanoscale aids in understanding the damage mechanism of metals. While most atomistic simulations by far assume circular or spherical voids for simplicity, recent studies highlight the significance of the initial void ellipticity in mechanical response of voided metals. In this work, we perform large scale molecular dynamics simulations with millions of atoms to investigate the void growth in plastic deformation of thin films in face-centered cubic Cu. It is found that the initial ellipticity and the initial orientation angle of the void have substantial impacts on the dislocation nucleation, the void evolution, and the stress-strain response. In particular, the initial dislocation emission sites and the sequence of slip plane activation vary with the initial void geometry. For the void size evolution, three regimes are identified: (I) the porosity increases relatively slowly in the absence of dislocations, (II) the porosity grows much more rapidly after dislocations start to glide on different slip planes, and (III) the rate of porosity variation becomes much more slowly when dislocations are saturated in the model, and the void surface becomes irregular, non-smooth. In terms of the stress-strain response, the effects of the initial orientation angle are more pronounced when the initial void ellipticity is large; the influence of the initial void ellipticity is different for different initial orientation angles. The effects of the temperature, the strain rate, the loading direction, and the initial porosity in the void growth are also explored. Our results reveal the underlying mechanisms of initial void geometry-dependent plastic deformation of metallic thin films and shed light on informing more accurate theoretical models.

  1. On the validity of the classical hydrodynamic lubrication theory applied to squeeze film dampers

    International Nuclear Information System (INIS)

    Danaila, S; Moraru, L

    2010-01-01

    Squeeze film dampers (SFD) are devices utilized to control vibrations of the shafts of high-speed rotating machinery. The SFD - squirrel cage combination is probably the most used system for tuning the stiffness and damping of the supports for rotors installed on ball bearings. Squeeze film dampers are essentially hydrodynamic bearings which contain the ball bearings housings of ball-bearings supported shafts. Consequently, the oil film within the SFD are influenced only by the precession and nutation of the shaft, that is the flow of the oil within the damper is not directly influenced by the spin of the rotor. However, in the classical theory, the flow in the thin film is also governed by the Reynolds equation. In this paper, some of the limits of the classical theory of the SFD are discussed and theoretical and experimental studies, which illustrate the ideas presented herein, are presented as well. The orbits of an unbalanced rotor that is supported by a ball-bearings-SFD-squirrel-cage assembly at one end and by rigidly mounted ball bearings at the other end are computed using the bearing forces provided by the classical short bearing theory. The numerical model also includes the properties of the squirrel cage. The parameters of the squirrel cage were measured, together with the effect of the friction within the assembly. Experimental unbalance responses were also collected for various rotation speeds and unbalances to validate the numerical simulations.

  2. Predicting Tunnel Squeezing Using Multiclass Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Yang Sun

    2018-01-01

    Full Text Available Tunnel squeezing is one of the major geological disasters that often occur during the construction of tunnels in weak rock masses subjected to high in situ stresses. It could cause shield jamming, budget overruns, and construction delays and could even lead to tunnel instability and casualties. Therefore, accurate prediction or identification of tunnel squeezing is extremely important in the design and construction of tunnels. This study presents a modified application of a multiclass support vector machine (SVM to predict tunnel squeezing based on four parameters, that is, diameter (D, buried depth (H, support stiffness (K, and rock tunneling quality index (Q. We compiled a database from the literature, including 117 case histories obtained from different countries such as India, Nepal, and Bhutan, to train the multiclass SVM model. The proposed model was validated using 8-fold cross validation, and the average error percentage was approximately 11.87%. Compared with existing approaches, the proposed multiclass SVM model yields a better performance in predictive accuracy. More importantly, one could estimate the severity of potential squeezing problems based on the predicted squeezing categories/classes.

  3. Squeeze strengthening of magnetorheological fluids using mixed mode operation

    Science.gov (United States)

    Becnel, A. C.; Sherman, S. G.; Hu, W.; Wereley, N. M.

    2015-05-01

    This research details a novel method of increasing the shear yield stress of magnetorheological fluids by combining shear and squeeze modes of operation to manipulate particle chain structures, so-called squeeze strengthening. Using a custom built Searle cell magnetorheometer, which is a model device emulating a rotary magnetorheological energy absorber (MREA), the contribution of squeeze strengthening to the total controllable yield force is experimentally investigated. Using an eccentric rotating inner cylinder, characterization data from large (1 mm) and small (0.25 mm) nominal gap geometries are compared to investigate the squeeze strengthening effect. Details of the experimental setup and method are presented, and a hybrid model is used to explain experimental trends. This study demonstrates that it is feasible, utilizing squeeze strengthening to increase yield stress, to either (1) design a rotary MREA of a given volume to achieve higher energy absorption density (energy absorbed normalized by active fluid volume), or (2) reduce the volume of a given rotary MREA to achieve the same energy absorption density.

  4. Quantum Phonon Optics: Squeezing Quantum Noise in the Atomic Displacements.

    Science.gov (United States)

    Hu, X.; Nori, F.

    1996-03-01

    We have investigated(X. Hu and F. Nori, Physical Review B, in press; preprints.) coherent and squeezed quantum states of phonons. Squeezed states are interesting because they allow the possibility of modulating the quantum fluctuations of atomic displacements below the zero-point quantum noise level of phonon vacuum states. We have studiedfootnotemark[1] the possibility of squeezing quantum noise in the atomic displacement using a polariton-based approach and also a method based on the three-phonon anharmonic interaction. Our focus here is on the first approach. We have diagonalized the polariton Hamiltonian and calculated the corresponding expectation values and fluctuations of both the atomic displacement and the lattice amplitude operators (the later is the phonon analog of the electric field operator for photons). Our results shows that squeezing of quantum fluctuations in the atomic displacements can be achieved with appropriate initial states of both photon and phonon fields. The degree of squeezing is directly related to the crystal susceptibility, which is indicative of the interaction strength between the incident light and the crystal.

  5. Fourth International Conference on Squeezed States and Uncertainty Relations

    Science.gov (United States)

    Han, D. (Editor); Peng, Kunchi (Editor); Kim, Y. S. (Editor); Manko, V. I. (Editor)

    1996-01-01

    The fourth International Conference on Squeezed States and Uncertainty Relations was held at Shanxi University, Taiyuan, Shanxi, China, on June 5 - 9, 1995. This conference was jointly organized by Shanxi University, the University of Maryland (U.S.A.), and the Lebedev Physical Institute (Russia). The first meeting of this series was called the Workshop on Squeezed States and Uncertainty Relations, and was held in 1991 at College Park, Maryland. The second and third meetings in this series were hosted in 1992 by the Lebedev Institute in Moscow, and in 1993 by the University of Maryland Baltimore County, respectively. The scientific purpose of this series was initially to discuss squeezed states of light, but in recent years, the scope is becoming broad enough to include studies of uncertainty relations and squeeze transformations in all branches of physics, including, of course, quantum optics and foundations of quantum mechanics. Quantum optics will continue playing the pivotal role in the future, but the future meetings will include all branches of physics where squeeze transformations are basic transformation. This transition took place at the fourth meeting of this series held at Shanxi University in 1995. The fifth meeting in this series will be held in Budapest (Hungary) in 1997, and the principal organizer will be Jozsef Janszky of the Laboratory of Crystal Physics, P.O. Box 132, H-1052. Budapest, Hungary.

  6. Molecular-dynamics simulations of thin polyisoprene films confined between amorphous silica substrates

    International Nuclear Information System (INIS)

    Guseva, D. V.; Komarov, P. V.; Lyulin, Alexey V.

    2014-01-01

    Constant temperature–constant pressure (NpT) molecular-dynamics computer simulations have been carried out for the united-atom model of a non-crosslinked (1,4) cis-polyisoprene (PI) melt confined between two amorphous, fully coordinated silica surfaces. The Lennard-Jones 12-6 potential was implemented to describe the polymer–silica interactions. The thickness H of the produced PI–silica film has been varied in a wide range, 1 g g is the individual PI chain radius of gyration measured under the imposed confinement. After a thorough equilibration, the PI film stratified structure and polymer segmental dynamics have been studied. The chain structure in the middle of the films resembles that in a corresponding bulk, but the polymer-density profile shows a pronounced ordering of the polymer segments in the vicinity of silica surfaces; this ordering disappears toward the film middles. Tremendous slowing down of the polymer segmental dynamics has been observed in the film surface layers, with the segmental relaxation more than 150 times slower as compared to that in a PI bulk. This effect increases with decreasing the polymer-film thickness. The segmental relaxation in the PI film middles shows additional relaxation process which is absent in a PI bulk. Even though there are fast relaxation processes in the film middle, its overall relaxation is slower as compared to that in a bulk sample. The interpretation of the results in terms of polymer glassy bridges has been discussed

  7. Molecular Structure and Dynamics in Thin Water Films at the Silica and Graphite Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Argyris, Dr. Dimitrios [University of Oklahoma; Tummala, Dr. Naga Rajesh [University of Oklahoma; StrioloDr., A [Vanderbilt University; Cole, David R [ORNL

    2008-01-01

    The structure and dynamic properties of interfacial water at the graphite and silica solid surfaces were investigated using molecular dynamics simulations. The effect of surface properties on the characteristics of interfacial water was quantified by computing density profiles, radial distribution functions, surface density distributions, orientation order parameters, and residence and reorientation correlation functions. In brief, our results show that the surface roughness, chemical heterogeneity, and surface heterogeneous charge distribution affect the structural and dynamic properties of the interfacial water molecules, as well as their rate of exchange with bulk water. Most importantly, our results indicate the formation of two distinct water layers at the SiO2 surface covered by a large density of hydroxyl groups. Further analysis of the data suggests a highly confined first layer where the water molecules assume preferential hydrogen-down orientation and a second layer whose behavior and characteristics are highly dependent on those of the first layer through a well-organized hydrogen bond network. The results suggest that water-water interactions, in particular hydrogen bonds, may be largely responsible for macroscopic interfacial properties such as adsorption and contact angle.

  8. Entropy Squeezing in Coupled Field-Superconducting Charge Qubit with Intrinsic Decoherence

    Institute of Scientific and Technical Information of China (English)

    YAN Xue-Qun; SHAO Bin; ZOU Jian

    2007-01-01

    We investigate the entropy squeezing in the system of a superconducting charge qubit coupled to a single mode field. We find an exact solution of the Milburn equation for the system and discuss the influence of intrinsic decoherence on entropy squeezing. As a comparison, we also consider the variance squeezing. Our results show that in the absence of the intrinsic decoherence both entropy and variance squeezings have the same periodic properties of time,and occur at the same range of time. However, when the intrinsic decoherence is considered, we find that as the time going on the entropy squeezing disappears fast than the variance squeezing, there exists a range of time where entropy squeezing can occur but variance squeezing cannot.

  9. Quantum entanglement and nonlocality properties of two-mode Gaussian squeezed states

    International Nuclear Information System (INIS)

    Shao-Hua, Xiang; Bin, Shao; Ke-Hui, Song

    2009-01-01

    Quantum entanglement and nonlocality properties of a family of two-mode Gaussian pure states have been investigated. The results show that the entanglement of these states is determined by both the two-mode squeezing parameter and the difference of the two single-mode squeezing parameters. For the same two-mode squeezing parameter, these states show larger entanglement than the usual two-mode squeezed vacuum state. The violation of Bell inequality depends strongly on all the squeezing parameters of these states and disappears completely in the limit of large squeezing. In particular, these states can exhibit much stronger violation of local realism than two-mode squeezed vacuum state in the range of experimentally available squeezing values. (general)

  10. A study of structure and properties of molecularly thin methanol film using the modified surface forces apparatus.

    Science.gov (United States)

    Zhao, Gutian; Cai, Di; Wu, Gensheng; Tan, Qiyan; Xiang, Li; Zhang, Yin; Xiang, Nan

    2014-11-01

    A novel approach for studying the adsorption and evaporation processes of molecularly thin methanol film by the modified surface forces apparatus (M-SFA) is reported. This method can be used precisely to measure the thickness, morphology, and mechanical properties of the film confined between two mica surfaces in a real-time manner at gas atmosphere. By observing the adsorption and evaporation processes of the methanol molecule, it is found that the first adsorbed layer of the methanol film on the mica surface behaves as a solid-like structure. The thickness of this layer is measured to be about 3.2 Å, approximately equal to the diameter of a methanol molecule. Besides, this first adsorbed layer can carry normalized loads of more than 5.6 atm due to the carrying capacity conserved by the bond of mica-OH. The outer layers of the methanol film are further adsorbed with the increase of the exposure time, which are liquid-like and can be easily eliminated out from the substrate. The present study suggests that the interacting mode between hydroxy and mica is of great potential in material science and biomedical systems. © 2014 Wiley Periodicals, Inc.

  11. Avoiding polar catastrophe in the growth of polarly orientated nickel perovskite thin films by reactive oxide molecular beam epitaxy

    International Nuclear Information System (INIS)

    Yang, H. F.; Liu, Z. T.; Fan, C. C.; Xiang, P.; Zhang, K. L.; Li, M. Y.; Liu, J. S.; Yao, Q.; Shen, D. W.

    2016-01-01

    By means of the state-of-the-art reactive oxide molecular beam epitaxy, we synthesized (001)- and (111)-orientated polar LaNiO 3 thin films. In order to avoid the interfacial reconstructions induced by polar catastrophe, screening metallic Nb-doped SrTiO 3 and iso-polarity LaAlO 3 substrates were chosen to achieve high-quality (001)-orientated films in a layer-by-layer growth mode. For largely polar (111)-orientated films, we showed that iso-polarity LaAlO 3 (111) substrate was more suitable than Nb-doped SrTiO 3 . In situ reflection high-energy electron diffraction, ex situ high-resolution X-ray diffraction, and atomic force microscopy were used to characterize these films. Our results show that special attentions need to be paid to grow high-quality oxide films with polar orientations, which can prompt the explorations of all-oxide electronics and artificial interfacial engineering to pursue intriguing emergent physics like proposed interfacial superconductivity and topological phases in LaNiO 3 based superlattices.

  12. Molecular Processes Underlying the Structure and Assembly of Thin Films and Nanoparticles at Complex interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Richmond, Geraldine [Univ. of Oregon, Eugene, OR (United States)

    2016-06-03

    Since 1995 we have pursued a number of different studies that are quite diverse in nature but with the common theme of using novel laser based methods to study important processes at buried interfaces. Studies of Corrosion, Passivation on n-GaAs(100)Methanol Photoelectrochemical Cell In these studies we have used picosecond photoluminescence and electrochemical studies to understand the GaAs/methanol interface. In our most extensive set of studies we conducted photo-illumination and XPS experiments to understand the chemistry occurring in the GaAs/methanol photoelectrochemical during photoexcitation. An important distinction between photocorrosion and photoetching of GaAs is elucidated by these studies. The dependence of GaAs photocorrosion on light intensity has been explored to better understand intrinsic differences between the lamplight studies and the picosecond photoluminescence studies. The effect of coating the GaAs with a sulfide layer prior to immersion in the cell has also been explored. This last result has led us to examine n-GaAs as a function of crystallographic orientation after exposure to aqueous Na2S containing solutions has been studied as a function of crystallographic orientation of the GaAs surface. The (100) and (110) surfaces are relatively similar, with significant amounts of As-S species present at the interface. The (111)B surface lacks this constituent, but shows significant amounts of metallic As. The XPS results have been correlated with the results of previous photocorrosion and passivation studies conducted in a photoelectrochemical cell. The studies indicate that the metallic As present at (111)B surface contributes strongly to the large surface recombination velocity found there, and to the inability of Na2S to passivate the (111)B surface. SAMS Under Water: Water Molecular Structure and Bonding at Hydrophobic Surfaces In these DOE sponsored studies we have been interested in learning the similarities and

  13. Slowing Quantum Decoherence by Squeezing in Phase Space

    Science.gov (United States)

    Le Jeannic, H.; Cavaillès, A.; Huang, K.; Filip, R.; Laurat, J.

    2018-02-01

    Non-Gaussian states, and specifically the paradigmatic cat state, are well known to be very sensitive to losses. When propagating through damping channels, these states quickly lose their nonclassical features and the associated negative oscillations of their Wigner function. However, by squeezing the superposition states, the decoherence process can be qualitatively changed and substantially slowed down. Here, as a first example, we experimentally observe the reduced decoherence of squeezed optical coherent-state superpositions through a lossy channel. To quantify the robustness of states, we introduce a combination of a decaying value and a rate of decay of the Wigner function negativity. This work, which uses squeezing as an ancillary Gaussian resource, opens new possibilities to protect and manipulate quantum superpositions in phase space.

  14. Slip analysis of squeezing flow using doubly stratified fluid

    Science.gov (United States)

    Ahmad, S.; Farooq, M.; Javed, M.; Anjum, Aisha

    2018-06-01

    The non-isothermal flow is modeled and explored for squeezed fluid. The influence of velocity, thermal and solutal slip effects on transport features of squeezed fluid are analyzed through Darcy porous channel when fluid is moving due to squeezing of upper plate towards the stretchable lower plate. Dual stratification effects are illustrated in transport equations. A similarity analysis is performed and reduced governing flow equations are solved using moderated and an efficient convergent approach i.e. Homotopic technique. The significant effects of physical emerging parameters on flow velocity, temperature and fluid concentration are reporting through various plots. Graphical explanations for drag force, Nusselt and Sherwood numbers are stated and examined. The results reveal that minimum velocity field occurs near the plate, whereas it increases far away from the plate for strong velocity slip parameter. Furthermore, temperature and fluid concentration significantly decreases with increased slip effects. The current analysis is applicable in some advanced technological processes and industrial fluid mechanics.

  15. Pump-dump iterative squeezing of vibrational wave packets.

    Science.gov (United States)

    Chang, Bo Y; Sola, Ignacio R

    2005-12-22

    The free motion of a nonstationary vibrational wave packet in an electronic potential is a source of interesting quantum properties. In this work we propose an iterative scheme that allows continuous stretching and squeezing of a wave packet in the ground or in an excited electronic state, by switching the wave function between both potentials with pi pulses at certain times. Using a simple model of displaced harmonic oscillators and delta pulses, we derive the analytical solution and the conditions for its possible implementation and optimization in different molecules and electronic states. We show that the main constraining parameter is the pulse bandwidth. Although in principle the degree of squeezing (or stretching) is not bounded, the physical resources increase quadratically with the number of iterations, while the achieved squeezing only increases linearly.

  16. Novel polymeric phosphonate scale inhibitors for improved squeeze treatment lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, G.E.; Poynton, N.; McLaughlin, K.; Clark, D.R.

    1996-12-31

    New patented chemistry has provided an exciting discovery which may be used to reduce costs in scale squeeze applications. Phosphomethylated polyamines (PMPAs) have been found to possess outstanding adsorption-desorption properties which generate long squeeze lifetimes. This paper describes the core-flood tests and modelling work, which highlight these properties, plus additional scale inhibition performance studies to demonstrate the all-round capabilities of this chemistry for squeeze treatments. An example of a PMPA is used to show the extremely viable adsorption and desorption isotherms. These illustrate the efficient way in which the desorption occurs to minimise the chemical in the returns with a benefit of reduced chemical content in the discharge. The PMPA also demonstrates that both polymer and phosphonate properties can be embraced in a single product (e.g. dual scale control mechanisms) confirming that this chemistry is a true polymeric phosphonate. 13 refs., 12 figs., 1 tab.

  17. As-free pnictide LaNi{sub 1-x}Sb{sub 2} thin films grown by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Retzlaff, Reiner; Buckow, Alexander; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany)

    2012-07-01

    We use reactive molecular beam epitaxy (RMBE) as synthesis technique for the search of arsenic free pnictide superconductors. Epitaxial thin films of LaNi{sub 1-x}Sb{sub 2} were grown on (100)MgO substrates from elemental sources by simultaneous evaporation of high purity La, Ni and Sb metals by e-gun. The LaNi{sub 1-x}Sb{sub 2} thin films grow epitaxially and are (00l) oriented with high crystalline quality, as evident from RHEED and X-Ray diffraction studies. The Ni deficient LaNi{sub 1-x}Sb{sub 2} thin films show metallic behavior with a room temperature resistivity of 110 {mu}{Omega} cm, while the stoichiometric compound is a semiconductor/insulator. The isostructural compound with Bi as pnictide shows a superconducting transition with a T{sub C}(0) of 3.1 K.

  18. Super-Poissonian Shot Noise of Squeezed-Magnon Mediated Spin Transport.

    Science.gov (United States)

    Kamra, Akashdeep; Belzig, Wolfgang

    2016-04-08

    The magnetization of a ferromagnet (F) driven out of equilibrium injects pure spin current into an adjacent conductor (N). Such F|N bilayers have become basic building blocks in a wide variety of spin-based devices. We evaluate the shot noise of the spin current traversing the F|N interface when F is subjected to a coherent microwave drive. We find that the noise spectrum is frequency independent up to the drive frequency, and increases linearly with frequency thereafter. The low frequency noise indicates super-Poissonian spin transfer, which results from quasiparticles with effective spin ℏ^{*}=ℏ(1+δ). For typical ferromagnetic thin films, δ∼1 is related to the dipolar interaction-mediated squeezing of F eigenmodes.

  19. Waveguide Cavity Resonator as a Source of Optical Squeezing

    Science.gov (United States)

    Stefszky, M.; Ricken, R.; Eigner, C.; Quiring, V.; Herrmann, H.; Silberhorn, C.

    2017-04-01

    We present the generation of continuous-wave optical squeezing from a titanium-in-diffused lithium niobate waveguide resonator. We directly measure 2.9 ±0.1 dB of single-mode squeezing, which equates to a produced level of 4.9 ±0.1 dB after accounting for detection losses. This device showcases the current capabilities of this waveguide architecture and precipitates more complicated integrated continuous-wave quantum devices in the continuous-variable regime.

  20. Improvement of an Atomic Clock using Squeezed Vacuum

    DEFF Research Database (Denmark)

    Kruse, I.; Lange, K; Peise, Jan

    2016-01-01

    , the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0.......75 atoms to improve the clock sensitivity of 10000 atoms by 2.05+0.34−0.37  dB. The SQL poses a significant limitation for today’s microwave fountain clocks, which serve as the main time reference. We evaluate the major technical limitations and challenges for devising a next generation of fountain clocks...

  1. Low frequency phase signal measurement with high frequency squeezing

    OpenAIRE

    Zhai, Zehui; Gao, Jiangrui

    2011-01-01

    We calculate the utility of high-frequency squeezed-state enhanced two-frequency interferometry for low-frequency phase measurement. To use the high-frequency sidebands of the squeezed light, a two-frequency intense laser is used in the interferometry instead of a single-frequency laser as usual. We find that the readout signal can be contaminated by the high-frequency phase vibration, but this is easy to check and avoid. A proof-of-principle experiment is in the reach of modern quantum optic...

  2. Squeezing a wave packet with an angular-dependent mass

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Alexandre G M [Departamento de Ciencias Exatas, Universidade Federal Fluminense, Av. dos Trabalhadores 420, Volta Redonda RJ, CEP 27255-125 (Brazil)], E-mail: agmschmidt@gmail.com, E-mail: agmschmidt@pq.cnpq.br

    2009-06-19

    We present a new effect of position-dependent mass (PDM) systems: the possibility of creating squeezed wave packets at the partial revival times. We solve exactly the PDM Schroedinger equation for the two-dimensional quantum rotor with two effective masses {mu}({theta}), both free and interacting with a uniform electric field, and present their energy eigenvalues and eigenfunctions in terms of Mathieu functions. For the first one, in order to squeeze the wave packet it is necessary to apply an electric field; for the second one such an effect can be achieved without the field.

  3. Squeezing a wave packet with an angular-dependent mass

    International Nuclear Information System (INIS)

    Schmidt, Alexandre G M

    2009-01-01

    We present a new effect of position-dependent mass (PDM) systems: the possibility of creating squeezed wave packets at the partial revival times. We solve exactly the PDM Schroedinger equation for the two-dimensional quantum rotor with two effective masses μ(θ), both free and interacting with a uniform electric field, and present their energy eigenvalues and eigenfunctions in terms of Mathieu functions. For the first one, in order to squeeze the wave packet it is necessary to apply an electric field; for the second one such an effect can be achieved without the field

  4. Displacement of microwave squeezed states with Josephson parametric amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Ling; Baust, Alexander; Xie, Edwar; Schwarz, Manuel; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Fedorov, Kirill; Menzel, Edwin; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Betzenbichler, Martin; Pogorzalek, Stefan; Haeberlein, Max; Eder, Peter; Goetz, Jan; Wulschner, Karl Friedrich; Huebl, Hans; Deppe, Frank [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany)

    2015-07-01

    Propagating quantum microwaves are promising building blocks for quantum communication. Interestingly, such itinerant quantum microwaves can be generated in the form of squeezed photon states by Josephson parametric amplifiers (JPA). We employ a specific ''dual-path'' setup for both state reconstruction and JPA characterization. Displacement operations are performed by using a directional coupler after the squeezing. We compare our results with theory predictions. In particular, we discuss our experiments in the context of remote state preparation and quantum teleportation with propagating microwaves.

  5. The Wigner distribution function for squeezed vacuum superposed state

    International Nuclear Information System (INIS)

    Zayed, E.M.E.; Daoud, A.S.; AL-Laithy, M.A.; Naseem, E.N.

    2005-01-01

    In this paper, we construct the Wigner distribution function for a single-mode squeezed vacuum mixed-state which is a superposition of the squeezed vacuum state. This state is defined as a P-representation for the density operator. The obtained Wigner function depends, beside the phase-space variables, on the mean number of photons occupied by the coherent state of the mode. This mean number relates to the mean free path through a given relation, which enables us to measure this number experimentally by measuring the mean free path

  6. Engineering squeezed states of microwave radiation with circuit quantum electrodynamics

    International Nuclear Information System (INIS)

    Li Pengbo; Li Fuli

    2011-01-01

    We introduce a squeezed state source for microwave radiation with tunable parameters in circuit quantum electrodynamics. We show that when a superconducting artificial multilevel atom interacting with a transmission line resonator is suitably driven by external classical fields, two-mode squeezed states of the cavity modes can be engineered in a controllable fashion from the vacuum state via adiabatic following of the ground state of the system. This scheme appears to be robust against decoherence and is realizable with present techniques in circuit quantum electrodynamics.

  7. A faster urethral pressure reflectometry technique for evaluating the squeezing function

    DEFF Research Database (Denmark)

    Klarskov, Niels; Saaby, Marie-Louise; Lose, Gunnar

    2013-01-01

    Abstract Objective. Urethral pressure reflectometry (UPR) has shown to be superior in evaluating the squeeze function compared to urethral pressure profilometry. The conventional UPR measurement (step method) required up to 15 squeezes to provide one measure of the squeezing opening pressure...

  8. Angle-resolved photoemission spectroscopy of strontium lanthanum copper oxide thin films grown by molecular-beam epitaxy

    Science.gov (United States)

    Harter, John Wallace

    Among the multitude of known cuprate material families and associated structures, the archetype is "infinite-layer" ACuO2, where perfectly square and flat CuO2 planes are separated by layers of alkaline earth atoms. The infinite-layer structure is free of magnetic rare earth ions, oxygen chains, orthorhombic distortions, incommensurate superstructures, ordered vacancies, and other complications that abound among the other material families. Furthermore, it is the only cuprate that can be made superconducting by both electron and hole doping, making it a potential platform for decoding the complex many-body interactions responsible for high-temperature superconductivity. Research on the infinite-layer compound has been severely hindered by the inability to synthesize bulk single crystals, but recent progress has led to high-quality superconducting thin film samples. Here we report in situ angle-resolved photoemission spectroscopy measurements of epitaxially-stabilized Sr1-chiLa chiCuO2 thin films grown by molecular-beam epitaxy. At low doping, the material exhibits a dispersive lower Hubbard band typical of other cuprate parent compounds. As carriers are added to the system, a continuous evolution from Mott insulator to superconducting metal is observed as a coherent low-energy band develops on top of a concomitant remnant lower Hubbard band, gradually filling in the Mott gap. For chi = 0.10, our results reveal a strong coupling between electrons and (pi,pi) anti-ferromagnetism, inducing a Fermi surface reconstruction that pushes the nodal states below the Fermi level and realizing nodeless superconductivity. Electron diffraction measurements indicate the presence of a surface reconstruction that is consistent with the polar nature of Sr1-chiLachiCuO2. Most knowledge about the electron-doped side of the cuprate phase diagram has been deduced by generalizing from a single material family, Re2-chi CechiCuO4, where robust antiferromagnetism has been observed past chi

  9. An Observation of Diamond-Shaped Particle Structure in a Soya Phosphatidylcohline and Bacteriorhodopsin Composite Langmuir Blodgett Film Fabricated by Multilayer Molecular Thin Film Method

    Science.gov (United States)

    Tsujiuchi, Y.; Makino, Y.

    A composite film of soya phosphatidylcohline (soya PC) and bacteriorhodopsin (BR) was fabricated by the multilayer molecular thin film method using fatty acid and lipid on a quartz substrate. Direct Force Microscopy (DFM), UV absorption spectra and IR absorption spectra of the film were characterized on the detail of surface structure of the film. The DFM data revealed that many rhombus (diamond-shaped) particles were observed in the film. The spectroscopic data exhibited the yield of M-intermediate of BR in the film. On our modelling of molecular configuration indicate that the coexistence of the strong inter-molecular interaction and the strong inter-molecular interaction between BR trimmers attributed to form the particles.

  10. Optical bistability of a thin film of resonant atoms in a phase-sensitive thermostate

    International Nuclear Information System (INIS)

    Basharov, A.M.

    1995-01-01

    It is shown theoretically that when a thin film of two-level atoms interacting with a resonant coherent electromagnetic wave is additionally illuminated with a squeezed field, a bistable transmission/reflection regime for coherent waves is obtained. This regime depends strongly on the phase difference between the coherent and the squeezed fields. New regimes, including a bistable regime, for the interaction of a coherent field with a film of resonant atoms are predicted based on this phenomenon. 14 refs., 5 figs

  11. A generalized Collins formula derived by virtue of the displacement-squeezing related squeezed coherent state representation

    International Nuclear Information System (INIS)

    Chuan-Mei, Xie; Shao-Long, Wan; Hong-Yi, Fan

    2010-01-01

    Based on the displacement-squeezing related squeezed coherent state representation |z) g and using the technique of integration within an ordered product of operators, this paper finds a generalized Fresnel operator, whose matrix element in the coordinate representation leads to a generalized Collins formula (Huygens–Fresnel integration transformation describing optical diffraction). The generalized Fresnel operator is derived by a quantum mechanical mapping from z to sz - rz * in the |z) g representation, while |z) g in phase space is graphically denoted by an ellipse. (classical areas of phenomenology)

  12. Growth of Pb(Ti,Zr)O 3 thin films by metal-organic molecular beam epitaxy

    Science.gov (United States)

    Avrutin, V.; Liu, H. Y.; Izyumskaya, N.; Xiao, B.; Özgür, Ü.; Morkoç, H.

    2009-02-01

    Single-crystal Pb(Zr xTi 1-x)O 3 thin films have been grown on (0 0 1) SrTiO 3 and SrTiO 3:Nb substrates by molecular beam epitaxy using metal-organic source of Zr and two different sources of reactive oxygen—RF plasma and hydrogen-peroxide sources. The same growth modes and comparable structural properties were observed for the films grown with both oxygen sources, while the plasma source allowed higher growth rates. The films with x up to 0.4 were single phase, while attempts to increase x beyond gave rise to the ZrO 2 second phase. The effects of growth conditions on growth modes, Zr incorporation, and phase composition of the Pb(Zr xTi 1-x)O 3 films are discussed. Electrical and ferroelectric properties of the Pb(Zr xTi 1-x)O 3 films of ~100 nm in thickness grown on SrTiO 3:Nb were studied using current-voltage, capacitance-voltage, and polarization-field measurements. The single-phase films show low leakage currents and large breakdown fields, while the values of remanent polarization are low (around 5 μC/cm 2). It was found that, at high sweep fields, the contribution of the leakage current to the apparent values of remanent polarization can be large, even for the films with large electrical resistivity (˜10 8-10 9 Ω cm at an electric filed of 1 MV/cm). The measured dielectric constant ranges from 410 to 260 for Pb(Zr 0.33Ti 0.67)O 3 and from 313 to 213 for Pb(Zr 0.2Ti 0.8)O 3 in the frequency range from 100 to 1 MHz.

  13. Probe transparency in a two-level medium embedded by a squeezed vacuum

    International Nuclear Information System (INIS)

    Swain, S.; Zhou, P.

    1994-08-01

    Effect of the detuning on the probe absorption spectra of a two-level system with and without a classically driven field in a squeezed vacuum is investigated. For a strong squeezing, there is a threshold which determines the positions and widths of the absorption peaks, for the squeezed parameter M. In a large detuning, the spectra exhibit some resemblance to the Fano spectrum. The squeezing-induced transparency occurs at the frequency 2ω L - ω A in the minimum-uncertainty squeezed vacuum. This effect is not phase-sensitive. (author). 15 refs, 8 figs

  14. Squeezing and entangling nuclear spins in helium 3

    DEFF Research Database (Denmark)

    Reinaudi, Gael; Sinatra, Alice; Dantan, Aurelien Romain

    2007-01-01

    We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of 3He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study t...

  15. Light squeezing in optical parametric amplification beyond the ...

    Indian Academy of Sciences (India)

    of the medium the squeezing effect is increased, the same property we have obtained in our present study. ... classical case [2,9], the introduction of the idler mode from the rare side of the medium, a2(0), is necessary to ... ever, in contrast with the coherent state, the combination mode has unequal uncertainty. 0. 0.02. 0.04.

  16. Quantum reconstruction of an intense polarization squeezed optical state

    DEFF Research Database (Denmark)

    Marquardt, Ch.; Heersink, J.; Dong, R.

    2007-01-01

    We perform a reconstruction of the polarization sector of the density matrix of an intense polarization squeezed beam starting from a complete set of Stokes measurements. By using an appropriate quasidistribution, we map this onto the Poincare space, providing a full quantum mechanical characteri...

  17. Squeezed states from a quantum deformed oscillator Hamiltonian

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, R. [IFLP, CONICET–Department of Mathematics, University of La Plata c.c. 67 1900, La Plata (Argentina); Reboiro, M., E-mail: marta.reboiro@gmail.com [IFLP, CONICET–Department of Physics, University of La Plata c.c. 67 1900, La Plata (Argentina)

    2016-03-11

    The spectrum and the time evolution of a system, which is modeled by a non-hermitian quantum deformed oscillator Hamiltonian, is analyzed. The proposed Hamiltonian is constructed from a non-standard realization of the algebra of Heisenberg. We show that, for certain values of the coupling constants and for a range of values of the deformation parameter, the deformed Hamiltonian is a pseudo-hermitic Hamiltonian. We explore the conditions under which the Hamiltonian is similar to a Swanson Hamiltonian. Also, we show that the lowest eigenstate of the system is a squeezed state. We study the time evolution of the system, for different initial states, by computing the corresponding Wigner functions. - Highlights: • A generalization of the squeezed harmonic oscillator is constructed from a non-standard realization of the Heisenberg algebra. • It is proved that, for certain values of the parameters of the model, the Hamiltonian is a pseudo-hermitian Hamiltonian. • It is shown that the lowest eigenstate of the Hamiltonian is a squeezed state. • The squeezing behavior of the associated Gazeau–Klauder state, as a function of time, is discussed.

  18. Scoping study on coastal squeeze in the Ayeyarwady Delta

    NARCIS (Netherlands)

    Kroon, M.E.N.; Rutten, M.M.; Stive, M.J.F.; Wunna, S.

    2015-01-01

    Coastal squeeze is the reduction in the space of coastal habitats to operate (Phan et al, 2014) and an important cause for coastline retreat, increase in flood risk, salinity intrusion etc. Land use changes, such as deforestation and urbanization, reduce the space of natural habitats, such as

  19. A Study Of Magnetic Fluid Based Squeeze Film Between Porous ...

    African Journals Online (AJOL)

    Efforts have been made to study and analyze the effect of surface roughness on the performance of magnetic fluid based squeeze film between porous elliptic plates. The transverse roughness of the bearing surface is characterized by a stochastic random variable with non-zero mean, variance and skewness.

  20. US nuclear industry plans squeeze on O and M costs

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The United States nuclear industry, still the largest in the world with 107 operating commercial plants, wants to squeeze still more fat out of operation and maintenance costs. Success or failure could decide whether many operating units remain competitive with other forms of baseload electricity generation over the coming decade. (Author)

  1. Estimating the distribution of salt cavern squeeze using subsidence measurements

    NARCIS (Netherlands)

    Fokker, P.A.; Visser, J.

    2014-01-01

    We report a field study on solution mining of magnesium chloride from bischofite layers in the Netherlands at depths between 1500 and 1850 m. Subsidence that was observed in the area is due to part of the brine production being realized by cavern squeeze; some of which were connccted. Wc used an

  2. Polarization squeezing and entanglement produced by a frequency doubler

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Buchhave, Preben

    2003-01-01

    The quantum mechanical polarization properties of a nondegenerate second harmonic generator, where a nonlinear type II crystal is placed inside a cavity, are investigated theoretically. We demonstrate the possibility of strong squeezing of the continuous Stokes parameters as well as strong...... entanglement between them....

  3. Geometric phases for nonlinear coherent and squeezed states

    International Nuclear Information System (INIS)

    Yang Dabao; Chen Ying; Chen Jingling; Zhang Fulin

    2011-01-01

    The geometric phases for standard coherent states which are widely used in quantum optics have attracted considerable attention. Nevertheless, few physicists consider the counterparts of nonlinear coherent states, which are useful in the description of the motion of a trapped ion. In this paper, the non-unitary and non-cyclic geometric phases for two nonlinear coherent and one squeezed states are formulated, respectively. Moreover, some of their common properties are discussed, such as gauge invariance, non-locality and nonlinear effects. The nonlinear functions have dramatic impacts on the evolution of the corresponding geometric phases. They speed the evolution up or down. So this property may have an application in controlling or measuring geometric phase. For the squeezed case, when the squeezed parameter r → ∞, the limiting value of the geometric phase is also determined by a nonlinear function at a given time and angular velocity. In addition, the geometric phases for standard coherent and squeezed states are obtained under a particular condition. When the time evolution undergoes a period, their corresponding cyclic geometric phases are achieved as well. And the distinction between the geometric phases of the two coherent states may be regarded as a geometric criterion.

  4. Squeezing effects of an atom laser: Beyond the linear model

    International Nuclear Information System (INIS)

    Jing Hui; Ge Molin; Chen Jingling

    2002-01-01

    We investigate the quantum dynamics and statistics of an atom laser by taking into account binary atom-atom collisions. The rotating wave approximation Hamiltonian of the system is solved analytically . We show that the nonlinear atom-atom interactions could yield periodic quadrature squeezing effects in the atom laser output beam, although the input radio frequency field is in a Glauber coherent state

  5. Light squeezing in optical parametric amplification beyond the ...

    Indian Academy of Sciences (India)

    The variances have different signs for a range of values of and their variations are in opposite directions. We also show that this property is strongly dependent on the relative refractive index of the medium (). It is worth mentioning that the relative index dependency is not an explicit feature in squeezing of OPA under ...

  6. Why the Marriage Squeeze Cannot Cause Dowry Inflation

    NARCIS (Netherlands)

    Anderson, K.S.

    2000-01-01

    It has been argued that rising dowry payments are caused by population growth.According to that explanation, termed the `marriage squeeze', a population increase leads to an excess supply of brides since men marry younger women.As a result, dowry payments rise in order to clear the marriage

  7. Entropy squeezing for a two-level atom in the Jaynes-Cummings model with an intensity-depend coupling

    Institute of Scientific and Technical Information of China (English)

    李春先; 方卯发

    2003-01-01

    We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.

  8. Entropy squeezing for a two—level atom in the Jaynes—Cummings model with an intensity—depend coupling

    Institute of Scientific and Technical Information of China (English)

    李春先; 方卯发; 等

    2003-01-01

    We study the squeezing for a two-level atom in the Jaynes-Cumings model with intensity-dependent coupling using quantum information entropy,and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing.Our results show that,the squeezed component number depends on the atomic initial distribution angle,while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing.Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.

  9. Short-time fourth-order squeezing effects in spontaneous and stimulated four- and six-wave mixing processes

    International Nuclear Information System (INIS)

    Giri, Dilip Kumar; Gupta, P S

    2003-01-01

    The concept of fourth-order squeezing of the electromagnetic field is investigated in the fundamental mode in spontaneous and stimulated four- and six-wave mixing processes under the short-time approximation based on a fully quantum mechanical approach. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established. The possibility of obtaining fourth-order squeezing is studied. The dependence of fourth-order squeezing on the number of photons is also investigated. It is shown that fourth-order squeezing, which is a higher-order squeezing, allows a much larger fractional noise reduction than lower-order squeezing. It is shown that squeezing is greater in a stimulated process than the corresponding squeezing in spontaneous interaction. The conditions for obtaining maximum and minimum squeezing are obtained. We have also established the non-classical nature of squeezed radiation using the Glauber-Sudarshan representation

  10. Long-Wave Infrared (LWIR) Molecular Laser-Induced Breakdown Spectroscopy (LIBS) Emissions of Thin Solid Explosive Powder Films Deposited on Aluminum Substrates.

    Science.gov (United States)

    Yang, Clayton S-C; Jin, Feng; Trivedi, Sudhir B; Brown, Ei E; Hommerich, Uwe; Tripathi, Ashish; Samuels, Alan C

    2017-04-01

    Thin solid films made of high nitro (NO 2 )/nitrate (NO 3 ) content explosives were deposited on sand-blasted aluminum substrates and then studied using a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared region (LWIR; ∼5.6-10 µm). Despite the similarities of their chemical compositions and structures, thin films of three commonly used explosives (RDX, HMX, and PETN) studied in this work can be rapidly identified in the ambient air by their molecular LIBS emission signatures in the LWIR region. A preliminary assessment of the detection limit for a thin film of RDX on aluminum appears to be much lower than 60 µg/cm 2 . This LWIR LIBS setup is capable of rapidly probing and charactering samples without the need for elaborate sample preparation and also offers the possibility of a simultaneous ultraviolet visible and LWIR LIBS measurement.

  11. High performance inkjet-printed metal oxide thin film transistors via addition of insulating polymer with proper molecular weight

    Science.gov (United States)

    Sun, Dawei; Chen, Cihai; Zhang, Jun; Wu, Xiaomin; Chen, Huipeng; Guo, Tailiang

    2018-01-01

    Fabrication of metal oxide thin film transistor (MOTFT) arrays using the inkjet printing process has caused tremendous interest for low-cost and large-area flexible electronic devices. However, the inkjet-printed MOTFT arrays usually exhibited a non-uniform geometry due to the coffee ring effect, which restricted their commercial application. Therefore, in this work, a strategy is reported to control the geometry and enhance device performance of inkjet-printed MOTFT arrays by the addition of an insulating polymer to the precursor solution prior to film deposition. Moreover, the impact of the polymer molecular weight (MW) on the geometry, chemical constitution, crystallization, and MOTFT properties of inkjet-printed metal oxide depositions was investigated. The results demonstrated that with an increase of MW of polystyrene (PS) from 2000 to 200 000, the coffee ring was gradually faded and the coffee ring effect was completely eliminated when MW reached 200 000, which is associated with the enhanced viscosity with the insulating polymer, providing a high resistance to the outward capillary flow, which facilitated the depinning of the contact line, leading to the elimination of the coffee ring. More importantly, the carrier mobility increased significantly from 4.2 cm2 V-1 s-1 up to 13.7 cm2 V-1 s-1 as PS MW increased from 2000 to 200 000, which was about 3 times that of the pristine In2O3 TFTs. Grazing incidence X-ray diffraction and X-ray photoelectron spectroscopy results indicated that PS doping of In2O3 films not only frustrated crystallization but also altered chemical constitution by enhancing the formation of the M-O structure, both of which facilitated the carrier transport. These results demonstrated that the simple polymer additive process provides a promising method that can efficiently control the geometry of MO arrays during inkjet printing and maximize the device performance of MOTFT arrays, which showed great potential for the application in next

  12. Coherent interference effects and squeezed light generation in optomechanical systems

    Science.gov (United States)

    Qu, Kenan

    My Ph.D. dissertation is on the fundamental effects in optomechanical systems (OMS) and their important applications. The OMS are based on the possibility of the mechanical motion produced by few photons incident on the mechanical device. This dissertation presents several applications of the OMS in the area of storage of light in long-lived phonons, single mode optomechanical Ramsey interferometry, and generation of large amount of squeezing in the output radiation. The long-lived phonons can be monitored and controlled via optical means as was experimentally demonstrated. To show this, I develop the theory of transient electromagnetically induced transparency (EIT). For further applications like state transfer, especially over very different frequency regimes, I consider double-cavity OMS, where the two cavities can correspond to different spectral domains, yet the state transfer is possible via phonons. The state transfer is based on a new effect, electromagnetically induced absorption (EIA), where one uses a second control field from the other cavity to produce an absorption peak inside the EIT window. All these involve the interference of various path ways via which a final state is reached. The following chapter shows how Fano-like interference can arise in OMS. A Fano asymmetry parameter for OMS was defined. The last two chapters deal with the question if OMS can be efficient generators of squeezed light. I show by blue and red tuning the two cavities in a double-cavity OMS, one can generate effectively a two-mode parametric interaction which yields two-mode squeezed output with the squeezing magnitude of the order of 10dB. This requires a bath temperature of 10mK. Such temperatures obtained by using Helium dilution refrigerator are routinely used with superconducting OMS. The major part of this dissertation is devoted to the dispersive optomechanical interaction. However, the interaction can also be dissipative, where the mechanical displacement modulates

  13. Superconducting thin films of As-free pnictide LaPd{sub 1-x}Sb{sub 2} grown by reactive molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Retzlaff, Reiner; Buckow, Alexander; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany)

    2013-07-01

    We use reactive molecular beam epitaxy as synthesis technique for the search of arsenic free pnictide superconductors. Epitaxial thin films of LaPd{sub 1-x}Sb{sub 2} were grown on (100) MgO substrates from elemental sources by simultaneous evaporation of high purity La, Pd and Sb metals by e-gun. LaPd{sub 1-x}Sb{sub 2} belongs to a novel class of pnictide superconductors with a peculiar pnictide square net layer. Previously, we have reported epitaxial growth of isostructural Bi based compounds. The substitution of Bi by Sb leads to thin films with metallic behavior and room temperature resistivity of about 85 μΩ cm. The highest observed transition temperature T{sub c} inLaPd{sub 1-x}Sb{sub 2} is 3.1 K and does not depend on x. We discuss strategies to increase T{sub c} in this pnictide subfamily.

  14. Squeezed states and Hermite polynomials in a complex variable

    International Nuclear Information System (INIS)

    Ali, S. Twareque; Górska, K.; Horzela, A.; Szafraniec, F. H.

    2014-01-01

    Following the lines of the recent paper of J.-P. Gazeau and F. H. Szafraniec [J. Phys. A: Math. Theor. 44, 495201 (2011)], we construct here three types of coherent states, related to the Hermite polynomials in a complex variable which are orthogonal with respect to a non-rotationally invariant measure. We investigate relations between these coherent states and obtain the relationship between them and the squeezed states of quantum optics. We also obtain a second realization of the canonical coherent states in the Bargmann space of analytic functions, in terms of a squeezed basis. All this is done in the flavor of the classical approach of V. Bargmann [Commun. Pure Appl. Math. 14, 187 (1961)

  15. Luminescence and squeezing of a superconducting light-emitting diode

    Science.gov (United States)

    Hlobil, Patrik; Orth, Peter P.

    2015-05-01

    We investigate a semiconductor p -n junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a sharp frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence that results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. We show that the squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This reveals how the macroscopic coherence of a superconductor can be used to control the properties of light.

  16. QUANTUM MECHANICS. Quantum squeezing of motion in a mechanical resonator.

    Science.gov (United States)

    Wollman, E E; Lei, C U; Weinstein, A J; Suh, J; Kronwald, A; Marquardt, F; Clerk, A A; Schwab, K C

    2015-08-28

    According to quantum mechanics, a harmonic oscillator can never be completely at rest. Even in the ground state, its position will always have fluctuations, called the zero-point motion. Although the zero-point fluctuations are unavoidable, they can be manipulated. Using microwave frequency radiation pressure, we have manipulated the thermal fluctuations of a micrometer-scale mechanical resonator to produce a stationary quadrature-squeezed state with a minimum variance of 0.80 times that of the ground state. We also performed phase-sensitive, back-action evading measurements of a thermal state squeezed to 1.09 times the zero-point level. Our results are relevant to the quantum engineering of states of matter at large length scales, the study of decoherence of large quantum systems, and for the realization of ultrasensitive sensing of force and motion. Copyright © 2015, American Association for the Advancement of Science.

  17. Deformed two-photon squeezed states in noncommutative space

    International Nuclear Information System (INIS)

    Zhang Jianzu

    2004-01-01

    Recent studies on nonperturbation aspects of noncommutative quantum mechanics explored a new type of boson commutation relations at the deformed level, described by deformed annihilation-creation operators in noncommutative space. This correlated boson commutator correlates different degrees of freedom, and shows an essential influence on dynamics. This Letter devotes to the development of formalism of deformed two-photon squeezed states in noncommutative space. General representations of deformed annihilation-creation operators and the consistency condition for the electromagnetic wave with a single mode of frequency in noncommunicative space are obtained. Two-photon squeezed states are studied. One finds that variances of the dimensionless Hermitian quadratures of the annihilation operator in one degree of freedom include variances in the other degree of freedom. Such correlations show the new feature of spatial noncommutativity and allow a deeper understanding of the correlated boson commutator

  18. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  19. Encoding qubits into oscillators with atomic ensembles and squeezed light

    Science.gov (United States)

    Motes, Keith R.; Baragiola, Ben Q.; Gilchrist, Alexei; Menicucci, Nicolas C.

    2017-05-01

    The Gottesman-Kitaev-Preskill (GKP) encoding of a qubit within an oscillator provides a number of advantages when used in a fault-tolerant architecture for quantum computing, most notably that Gaussian operations suffice to implement all single- and two-qubit Clifford gates. The main drawback of the encoding is that the logical states themselves are challenging to produce. Here we present a method for generating optical GKP-encoded qubits by coupling an atomic ensemble to a squeezed state of light. Particular outcomes of a subsequent spin measurement of the ensemble herald successful generation of the resource state in the optical mode. We analyze the method in terms of the resources required (total spin and amount of squeezing) and the probability of success. We propose a physical implementation using a Faraday-based quantum nondemolition interaction.

  20. Globalisation squeezes the public sector - is it so obvious?

    DEFF Research Database (Denmark)

    Andersen, Torben M.; Sørensen, Allan

    It is widely perceived that globalization squeezes public sector activities by making taxation more costly. This is attributed to increased factor mobility and to a more elastic labour demand due to improved scope for relocation of production and thus employment across countries. We argue...... that this consensus view overlooks that gains from trade unambiguously work to lower the marginal costs of public funds, and moreover that globalization via increased trade in intermediaries may actually lower the labour demand elasticity....

  1. An Experimental Study on Steel and Teflon Squeeze Film Dampers

    Directory of Open Access Journals (Sweden)

    Asad A. Khalid

    2006-01-01

    Full Text Available In this paper, the vibration analysis on Teflon and steel squeeze film dampers has been carried out. At different frequency ranges, vibration amplitude and the resonance frequency are measured. The eccentricity ratio at resonance speed has been determined. Results show that the vibration amplitude of the steel damper is 10% less at resonance compared with the Teflon damper. On the other hand, saving weight of 36% has been achieved by using the Teflon damper.

  2. Noncritical quadrature squeezing through spontaneous polarization symmetry breaking

    OpenAIRE

    Garcia-Ferrer, Ferran V.; Navarrete-Benlloch, Carlos; de Valcárcel, Germán J.; Roldán, Eugenio

    2010-01-01

    We discuss the possibility of generating noncritical quadrature squeezing by spontaneous polarization symmetry breaking. We consider first type-II frequency-degenerate optical parametric oscillators, but discard them for a number of reasons. Then we propose a four-wave mixing cavity in which the polarization of the output mode is always linear but has an arbitrary orientation. We show that in such a cavity complete noise suppression in a quadrature of the output field occurs, irrespective of ...

  3. Noncritical quadrature squeezing through spontaneous polarization symmetry breaking.

    Science.gov (United States)

    Garcia-Ferrer, Ferran V; Navarrete-Benlloch, Carlos; de Valcárcel, Germán J; Roldán, Eugenio

    2010-07-01

    We discuss the possibility of generating noncritical quadrature squeezing by spontaneous polarization symmetry breaking. We first consider Type II frequency-degenerate optical parametric oscillators but discard them for a number of reasons. Then we propose a four-wave-mixing cavity, in which the polarization of the output mode is always linear but has an arbitrary orientation. We show that in such a cavity, complete noise suppression in a quadrature of the output field occurs, irrespective of the parameter values.

  4. Possible Depolarization Mechanism due to Low Beta Squeeze

    International Nuclear Information System (INIS)

    Ranjbar, V.; Luccio, A.; Bai, M.

    2008-01-01

    Simulations reveal a potential depolarization mechanism during low beta squeeze. This depolarization appears to be driven by a spin tune modulation caused by spin precession through the strong low beta quads due to the vertical fields. The modulation of the spin tune introduces an additional snake resonance condition at ν s0 ± nν x - ν z l = integer which while the same numerology as the well known sextupole resonance, can operate in the absence of sextupole elements

  5. Quantum correlations induced by multiple scattering of quadrature squeezed light

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2006-01-01

    Propagating quadrature squeezed light through a multiple scattering random medium is found to induce pronounced spatial quantum correlations that have no classical analogue. The correlations are revealed in the number of photons transported through the sample that can be measured from the intensity...... fluctuations of the total transmission or reflection. In contrast, no pronounced spatial quantum correlations appear in the quadrature amplitudes where excess noise above the shot noise level is found....

  6. Third International Workshop on Squeezed States and Uncertainty Relations

    Science.gov (United States)

    Han, D. (Editor); Kim, Y. S. (Editor); Rubin, Morton H. (Editor); Shih, Yan-Hua (Editor); Zachary, Woodford W. (Editor)

    1994-01-01

    The purpose of these workshops is to bring together an international selection of scientists to discuss the latest developments in Squeezed States in various branches of physics, and in the understanding of the foundations of quantum mechanics. At the third workshop, special attention was given to the influence that quantum optics is having on our understanding of quantum measurement theory. The fourth meeting in this series will be held in the People's Republic of China.

  7. Sixth International Conference on Squeezed States and Uncertainty Relations

    Science.gov (United States)

    Han, D. (Editor); Kim, Y. S. (Editor); Solimento, S. (Editor)

    2000-01-01

    These proceedings contain contributions from about 200 participants to the 6th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'99) held in Naples May 24-29, 1999, and organized jointly by the University of Naples "Federico II," the University of Maryland at College Park, and the Lebedev Institute, Moscow. This was the sixth of a series of very successful meetings started in 1990 at the College Park Campus of the University of Maryland. The other meetings in the series were held in Moscow (1992), Baltimore (1993), Taiyuan P.R.C. (1995) and Balatonfuered, Hungary (1997). The present one was held at the campus Monte Sant'Angelo of the University "Federico II" of Naples. The meeting sought to provide a forum for updating and reviewing a wide range of quantum optics disciplines, including device developments and applications, and related areas of quantum measurements and quantum noise. Over the years, the ICSSUR Conference evolved from a meeting on quantum measurement sector of quantum optics, to a wide range of quantum optics themes, including multifacet aspects of generation, measurement, and applications of nonclassical light (squeezed and Schrodinger cat radiation fields, etc.), and encompassing several related areas, ranging from quantum measurement to quantum noise. ICSSUR'99 brought together about 250 people active in the field of quantum optics, with special emphasis on nonclassical light sources and related areas. The Conference was organized in 8 Sections: Squeezed states and uncertainty relations; Harmonic oscillators and squeeze transformations; Methods of quantum interference and correlations; Quantum measurements; Generation and characterisation of non-classical light; Quantum noise; Quantum communication and information; and Quantum-like systems.

  8. China's marriage squeeze: A decomposition into age and sex structure.

    Science.gov (United States)

    Jiang, Quanbao; Li, Xiaomin; Li, Shuzhuo; Feldman, Marcus W

    2016-06-01

    Most recent studies of marriage patterns in China have emphasized the male-biased sex ratio but have largely neglected age structure as a factor in China's male marriage squeeze. In this paper we develop an index we call "spousal sex ratio" (SSR) to measure the marriage squeeze, and a method of decomposing the proportion of male surplus into age and sex structure effects within a small spousal age difference interval. We project that China's marriage market will be confronted with a relatively severe male squeeze. For the decomposition of the cohort aged 30, from 2010 to 2020 age structure will be dominant, while from 2020 through 2034 the contribution of age structure will gradually decrease and that of sex structure will increase. From then on, sex structure will be dominant. The index and decomposition, concentrated on a specific female birth cohort, can distinguish spousal competition for single cohorts which may be covered by a summary index for the whole marriage market; these can also be used for consecutive cohorts to reflect the situation of the whole marriage market.

  9. Information Entropy Squeezing of a Two-Level Atom Interacting with Two-Mode Coherent Fields

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Juan; FANG Mao-Fa

    2004-01-01

    From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing.

  10. Flower-Like Squeezing in the Motion of a Laser-Driven Trapped Ion

    Science.gov (United States)

    Nguyen, Ba An; Truong, Minh Duc

    We investigate the Nth order amplitude squeezing in the fan-state |ξ2k,f>F which is a linear superposition of the 2k-quantum nonlinear coherent states. Unlike in usual states where an ellipse is the symbol of squeezing, a 4k-winged flower results in the fan state. We first derive the analytical expression of squeezing for arbitrary k, N, f and then study in detail the case of a laser-driven trapped ion characterized by a specific form of the nonlinear function f. We show that the lowest order in which squeezing may appear and the number of directions along which the amplitude may be squeezed depend only on k whereas the precise directions of squeezing are determined also by the other physical parameters involved. Finally, we present a scheme to produce such fan-states.

  11. The effect of film thickness and molecular structure on order and disorder in thin films of compositionally asymmetric block copolymers

    Science.gov (United States)

    Mishra, Vindhya

    Directed self-assembly of thin film block copolymers offer a high throughput-low cost route to produce next generation lithographic devices, if one can bring the defect densities in the self assembled patterns below tolerance limits. However, the ability to control the nanoscale structure or morphology in thin film block copolymers presents challenges due to confinement effects on equilibrium behavior. Using structure characterization techniques such as grazing incidence small angle X-ray scattering (GISAXS), transmission electron and atomic force microscopy as well as self-consistent field theory, we have investigated how film thickness, annealing temperature and block copolymer structure affects the equilibrium behavior of asymmetric block copolymer films. Our studies have revealed the complicated dependence of order-disorder transitions, order-order transitions and symmetry transitions on film thickness. We found that the thickness dependent transition in the packing symmetry of spherical morphology diblock copolymers can be suppressed by blending with a small amount of majority block homopolymer, which allowed us to resolve the driving force behind this transition. Defect densities in, and the order-disorder transition temperature of, thin films of graphoepitaxially aligned diblock copolymer cylinders showed surprising sensitivity to the microdomain spacing. Methods to mitigate defect formation in thin films have been identified. The challenge of quantification of structural order in these systems was overcome using GISAXS, which allowed us to study the phenomena of disordering in two and three dimensions. Through studies on block copolymers which exhibit an order-order transition in bulk, we found that that subtle differences in the packing frustration of the spherical and cylindrical phases as well as the higher configurational entropy of free chain ends at the surface can drive the equilibrium configuration in thin films away from the stable bulk structure

  12. Studies on phase transformation and molecular orientation in nanostructured zinc phthalocyanine thin films annealed at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Avijit; Biswas, Bipul; Majumder, Manisree; Sanyal, Manik Kumar; Mallik, Biswanath, E-mail: spbm@iacs.res.in

    2012-08-31

    Studies on the electronic and optical properties of thin films of organometallic compounds such as phthalocyanine are very important for the development of devices based on these compounds. The nucleation and grain growth mechanism play an important role for the final electronic as well as optoelectronic properties of the organic and organometallic thin films. The present article deals with the change in the film morphology, grain orientation of nanocrystallites and optical properties of zinc phthalocyanines (ZnPc) thin films as a function of the post deposition annealing temperature. The effect of annealing temperature on the optical and structural property of vacuum evaporated ZnPc thin films deposited at room temperature (30 Degree-Sign C) on quartz glass and Si(100) substrates has been investigated. The thin films have been characterized by the UV-vis optical absorption spectra, X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. From the studies of UV-vis absorption spectra and XRD data, a metastable {alpha} to {beta}-phase transformation has been observed when the thin films were annealed at a temperature greater than about 250 Degree-Sign C. The FESEM images have shown the particlelike structure at room temperature and the structure became rodlike when the films were annealed at high temperatures. TEM image of ZnPc film dissolved in ethanol has shown spectacular rod-shaped crystallites. High resolution transmission electron microscopy image of a single nanorod has shown beautiful 'honey-comb' like structure. Particle size and root mean square roughness were calculated from AFM images. The changes in band gap energy with increase in annealing temperature have been evaluated. - Highlights: Black-Right-Pointing-Pointer Morphology and orientation of grains in zinc phthalocyanine (ZnPc) thin films. Black

  13. Prediction of phonon thermal transport in thin GaAs, InAs and InP nanowires by molecular dynamics simulations: influence of the interatomic potential

    Energy Technology Data Exchange (ETDEWEB)

    Carrete, J; Longo, R C; Gallego, L J, E-mail: jesus.carrete@usc.es [Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)

    2011-05-06

    A number of different potentials are currently being used in molecular dynamics simulations of semiconductor nanostructures. Confusion can arise if an inappropriate potential is used. To illustrate this point, we performed direct molecular dynamics simulations to predict the room temperature lattice thermal conductivity {lambda} of thin GaAs, InAs and InP nanowires. In each case, simulations performed using the classical Harrison potential afforded values of {lambda} about an order of magnitude smaller than those obtained using more elaborate potentials (an Abell-Tersoff, as parameterized by Hammerschmidt et al for GaAs and InAs, and a potential of Vashishta type for InP). These results will be a warning to those wishing to use computer simulations to orient the development of quasi-one-dimensional systems as heat sinks or thermoelectric devices.

  14. A group property for the coherent state representation of fermionic squeezing operators

    Science.gov (United States)

    Fan, Hong-yi; Li, Chao

    2004-06-01

    For the two-mode fermionic squeezing operators we find that their coherent state projection operator representation make up a loyal representation, which is homomorphic to an SO(4) group, though the fermionic coherent states are not mutual orthogonal. Thus the result of successively operating with many fermionic squeezing operators on a state can be equivalent to a single operation. The fermionic squeezing operators are mappings of orthogonal transformations in Grassmann number pseudo-classical space in the fermionic coherent state representation.

  15. A group property for the coherent state representation of fermionic squeezing operators

    International Nuclear Information System (INIS)

    Fan Hongyi; Li Chao

    2004-01-01

    For the two-mode fermionic squeezing operators we find that their coherent state projection operator representation make up a loyal representation, which is homomorphic to an SO(4) group, though the fermionic coherent states are not mutual orthogonal. Thus the result of successively operating with many fermionic squeezing operators on a state can be equivalent to a single operation. The fermionic squeezing operators are mappings of orthogonal transformations in Grassmann number pseudo-classical space in the fermionic coherent state representation

  16. Spin squeezing of atomic ensembles via nuclear-electronic spin entanglement

    DEFF Research Database (Denmark)

    Fernholz, Thomas; Krauter, Hanna; Jensen, Kasper

    2008-01-01

    quantum limit for quantum memory experiments and applications in quantum metrology and is thus a complementary alternative to spin squeezing obtained via inter-atom entanglement. Squeezing of the collective spin is verified by quantum state tomography.......We demonstrate spin squeezing in a room temperature ensemble of 1012 Cesium atoms using their internal structure, where the necessary entanglement is created between nuclear and electronic spins of each individual atom. This state provides improvement in measurement sensitivity beyond the standard...

  17. Foamed cement for squeeze cementing low-pressure, highly permeable reservoirs

    International Nuclear Information System (INIS)

    Chmllowski, W.; Kondratoff, L.B.

    1992-01-01

    Four different cement squeezing techniques have been used on wells producing from the Keg River formation in the Rainbow Lake area of Alberta, Canada. This paper evaluates 151 cement squeeze treatments performed at 96 wellsites and compares the use of foam cement vs. conventional squeeze treatments and techniques. Discussion includes key aspects, such as candidate selection, slurry design, treatment design, economic evaluation, and operational considerations

  18. On the Generation of Intermediate Number Squeezed State of the Quantized Radiation Field

    Science.gov (United States)

    Baseia, B.; de Lima, A. F.; Bagnato, V. S.

    Recently, a new state of the quantized radiation field — the intermediate number squeezed state (INSS) — has been introduced in the literature: it interpolates between the number state |n> and the squeezed state |z, α>=Ŝ(z)|α>, and exhibits interesting nonclassical properties as antibunching, sub-Poissonian statistics and squeezing. Here we introduce a slight modification in the previous definition allowing us a proposal to generate the INSS. Nonclassical properties using a new set of parameters are also studied.

  19. Characterization of molecular organization in pentacene thin films on SiO{sub 2} surface using infrared spectroscopy, spectroscopic ellipsometry, and atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Frątczak, E.Z., E-mail: ewelinazofia@gmail.com [Faculty of Physics and Applied Informatics, University of Łódź, 90-236 Łódź, Pomorska 149/153 (Poland); Uznański, P., E-mail: puznansk@cbmm.lodz.pl [Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Łódź, Sienkiewicza 112 (Poland); Moneta, M.E. [Faculty of Physics and Applied Informatics, University of Łódź, 90-236 Łódź, Pomorska 149/153 (Poland)

    2015-07-29

    Highlights: • Pentacene thin films of different thickness grown onto SiO{sub 2} substrates were studied. • Polarized IR GATR spectra were recorded and conclusions on pentacene orientation were deduced. • Optical anisotropic properties and morphology of pentacene films were analyzed. • Dielectric properties vary to some extent with the film thickness. - Abstract: Thin films of pentacene of 32 and 100 nm thickness obtained by organic molecular beam deposition (OMBD) in high vacuum conditions onto silicon/native silica (Si/SiO{sub 2}) and fused silica substrates were examined. Alignment, anisotropic optical properties and morphology were studied in ambient conditions using infrared (IR) transmission and polarized grazing angle attenuated total reflection (GATR) techniques, variable angle spectroscopic ellipsometry (VASE), UV–VIS absorption, and atomic force microscopy (AFM). For the first time dichroic GATR IR spectra were recorded for such thin films and conclusions on pentacene orientation were deduced on the basis of dichroic ratio of the IR-active vibrations. The symmetry assignment of the vibrational transitions is also discussed. The films exhibit continuous globular texture with uniaxial alignment of pentacene molecules and strongly anisotropic optical properties evidenced in the ellipsometric measurements. The results revealed that there are some quantitative differences in the orientation and in the dielectric properties between the two pentacene films of different thickness.

  20. Ultra-selective defect-free interfacially polymerized molecular sieve thin-film composite membranes for H2 purification

    KAUST Repository

    Ali, Zain; Pacheco Oreamuno, Federico; Litwiller, Eric; Wang, Yingge; Han, Yu; Pinnau, Ingo

    2017-01-01

    method for reverse osmosis membranes. Defect-free thin-film composite membranes were formed demonstrating unprecedented mixed-gas H2/CO2 selectivity of ≈ 50 at 140 °C with H2 permeance of 350 GPU, surpassing the permeance/selectivity upper bound of all

  1. Synthesis of Sub-10 nm Two-Dimensional Covalent Organic Thin Film with Sharp Molecular Sieving Nanofiltration

    KAUST Repository

    Gadwal, Ikhlas; Sheng, Guan; Thankamony, Roshni Lilly; Liu, Yang; Li, Huifang; Lai, Zhiping

    2018-01-01

    We demonstrated here a novel and facile synthesis of two-dimensional (2D) covalent organic thin film with pore size around 1.5 nm using a planar, amphiphilic and substituted heptacyclic truxene based triamine and a simple dialdehyde as building

  2. Optimization of Squeeze Casting Parameters for 2017 A Wrought Al Alloy Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Najib Souissi

    2014-04-01

    Full Text Available This study applies the Taguchi method to investigate the relationship between the ultimate tensile strength, hardness and process variables in a squeeze casting 2017 A wrought aluminium alloy. The effects of various casting parameters including squeeze pressure, melt temperature and die temperature were studied. Therefore, the objectives of the Taguchi method for the squeeze casting process are to establish the optimal combination of process parameters and to reduce the variation in quality between only a few experiments. The experimental results show that the squeeze pressure significantly affects the microstructure and the mechanical properties of 2017 A Al alloy.

  3. Higher-order amplitude squeezing of photons propagating through a semiconductor

    International Nuclear Information System (INIS)

    Nguyen Ba An.

    1996-12-01

    Photon amplitude K th power squeezing is studied when the coherent photon propagates through a semiconductor containing the exciton. If the exciton is prepared initially in a coherent state, the photon may become amplitude K th power squeezed. It is shown that, in the short-time limit, the photon squeezing in the P direction does not appear at all while that in the X direction is possible for all the amplitude power K. In the latter case, the amount of squeezing is larger for higher power K. Dependences on all the system parameters as well as on the output light detection moment are investigated in detail. (author). 14 refs, 8 figs

  4. Interaction of a quantum well with squeezed light: Quantum-statistical properties

    International Nuclear Information System (INIS)

    Sete, Eyob A.; Eleuch, H.

    2010-01-01

    We investigate the quantum statistical properties of the light emitted by a quantum well interacting with squeezed light from a degenerate subthreshold optical parametric oscillator. We obtain analytical solutions for the pertinent quantum Langevin equations in the strong-coupling and low-excitation regimes. Using these solutions we calculate the intensity spectrum, autocorrelation function, and quadrature squeezing for the fluorescent light. We show that the fluorescent light exhibits bunching and quadrature squeezing. We also show that the squeezed light leads to narrowing of the width of the spectrum of the fluorescent light.

  5. Experimental test of the strongly nonclassical character of a noisy squeezed single-photon state

    DEFF Research Database (Denmark)

    Jezek, M.; Tipsmark, A.; Dong, R.

    2012-01-01

    We experimentally verify the quantum non-Gaussian character of a conditionally generated noisy squeezed single-photon state with a positive Wigner function. Employing an optimized witness based on probabilities of squeezed vacuum and squeezed single-photon states, we prove that the state cannot...... be expressed as a mixture of Gaussian states. In our experiment, the non-Gaussian state is generated by conditional subtraction of a single photon from a squeezed vacuum state. The state is probed with a homodyne detector and the witness is determined by averaging a suitable pattern function over the measured...

  6. Enhanced squeezing of a collective spin via control of its qudit subsystems.

    Science.gov (United States)

    Norris, Leigh M; Trail, Collin M; Jessen, Poul S; Deutsch, Ivan H

    2012-10-26

    Unitary control of qudits can improve the collective spin squeezing of an atomic ensemble. Preparing the atoms in a state with large quantum fluctuations in magnetization strengthens the entangling Faraday interaction. The resulting increase in interatomic entanglement can be converted into metrologically useful spin squeezing. Further control can squeeze the internal atomic spin without compromising entanglement, providing an overall multiplicative factor in the collective squeezing. We model the effects of optical pumping and study the tradeoffs between enhanced entanglement and decoherence. For realistic parameters we see improvements of ~10 dB.

  7. Squeezed light in an optical parametric oscillator network with coherent feedback quantum control.

    Science.gov (United States)

    Crisafulli, Orion; Tezak, Nikolas; Soh, Daniel B S; Armen, Michael A; Mabuchi, Hideo

    2013-07-29

    We present squeezing and anti-squeezing spectra of the output from a degenerate optical parametric oscillator (OPO) network arranged in different coherent quantum feedback configurations. One OPO serves as a quantum plant, the other as a quantum controller. The addition of coherent feedback enables shaping of the output squeezing spectrum of the plant, and is found to be capable of pushing the frequency of maximum squeezing away from the optical driving frequency and broadening the spectrum over a wider frequency band. The experimental results are in excellent agreement with the developed theory, and illustrate the use of coherent quantum feedback to engineer the quantum-optical properties of the plant OPO output.

  8. A gravitational wave detector operating beyond the quantum shot-noise limit: Squeezed light in application

    Directory of Open Access Journals (Sweden)

    Schnabel Roman

    2013-08-01

    Full Text Available This contribution reviews our recent progress on the generation of squeezed light [1], and also the recent squeezed-light enhancement of the gravitational wave detector GEO 600 [2]. GEO 600 is currently the only GW observatory operated by the LIGO Scientific Collaboration in its search for gravitational waves. With the help of squeezed states of light it now operates with its best ever sensitivity, which not only proves the qualification of squeezed light as a key technology for future gravitational wave astronomy but also the usefulness of quantum entanglement.

  9. Manipulation of Squeezed Two-Phonon Bound States using Femtosecond Laser Pulses

    Directory of Open Access Journals (Sweden)

    Nakamura Kazutaka G.

    2013-03-01

    Full Text Available Two-phonon bound states have been excited exclusively in ZnTe(110 via impulsive stimulated second-order Raman scattering, essentially being squeezed states due to phase coherent excitation of two identical components anticorrelated in the wave vector. By using coherent control technique with a pair of femtosecond laser pulses, the manipulation of squeezed states has been demonstrated in which both the amplitude and lifetime of coherent oscillations of squeezed states are modulated, indicating the feasibility to control the quantum noise and the quantum nature of phonon squeezed states, respectively.

  10. Squeezing survival and transfer in single and double electromagnetically induced transparency

    International Nuclear Information System (INIS)

    Ding, J L; Hou, B P; Wang, S J

    2010-01-01

    We investigate the propagation and storage of a squeezed vacuum as the probe light in a collection of N four-level tripod configuration atoms under the condition of single or double electromagnetically induced transparency (EIT). The squeezing of the probe light is well preserved in both the single transparency channel and the double transparency one. On the other hand, the effects of the ground state dephasing rates on the propagation and storage of the squeezed vacuum are investigated. It is found that the maximum squeezing at the transparency points is suppressed by the dephasing rates in single or double EIT. Meanwhile, the mapping of the squeezing of the probe light onto the atomic ground coherences or onto the two atomic dark-state polaritons is also studied. In the absence of the Langevin atomic noise, the quasi-ideal squeezing transfer between the squeezed vacuum and the atomic ground coherences or the dark-state polaritons can be realized in such a system. When considering the Langevin atomic noise, the quantum characteristics of the atomic coherences at resonance are submerged by the Langevin noise, while in the scenario of the dark-state polariton, it is found that squeezing transfer onto one polariton is damaged, but the squeezing transfer onto the other polariton survives even in the presence of the Langevin noise.

  11. A low loss Faraday isolator for squeezed vacuum injection in Advanced LIGO

    Science.gov (United States)

    Goetz, Ryan; Tanner, David; Mueller, Guido

    2016-03-01

    Using conventional interferometry, the strain sensitivity of Advanced LIGO is limited by a quantum noise floor known as the standard quantum limit (SQL). Injecting squeezed vacuum states into the output port of the interferometer allows for detector sensitivities below the SQL at frequencies within a band of observational interest. The effectiveness of squeezing in reducing quantum noise is strongly dependent upon the optical loss in the squeezed path. Thus, to combine the squeezed vacuum state with the interferometer output we require a Faraday isolator with both high power-throughput efficiency and high isolation ratio. A prototype isolator is currently being developed, and we will discuss the design goals and current status.

  12. Giant surfactants of poly(ethylene oxide)- b-polystyrene-(molecular nanoparticle): nanoparticle-driven self-assembly with sub-10-nm nanostructures in thin films

    Science.gov (United States)

    Hsu, Chih-Hao; Lin, Zhiwei; Dong, Xue-Hui; Hsieh, I.-Fan; Cheng, Stephen Z. D.

    2014-03-01

    Giant surfactants are built upon precisely attaching shape- and volume-persistent molecular nanoparticles (MNP) to polymeric flexible tails. The unique class of self-assembling materials, giant surfactants, has been demonstrated to form self-assembled ordered nanostructures, and their self-assembly behaviors are remarkably sensitive to primary chemical structures. In this work, two sets of giant surfactants with functionalized MNP attached to diblock copolymer tails were studied in thin films. Carboxylic acid-functionalized [60]fullerene (AC60) tethered with PEO- b-PS (PEO-PS-AC60) represents an ABA' (hydrophilic-hydrophobic-hydrophilic) giant surfactant, and fluoro-functionalized polyhedral oligomeric silsesquioxane (FPOSS) tethered with PEO- b-PS (PEO-PS-FPOSS) represents an ABC (hydrophilic-hydrophobic-omniphobic) one. The dissimilar chemical natures of the MNPs result in different arrangement of MNPs in self-assembled structures, the dispersion of AC60 in PEO domain and the single domain of FPOSS. Moreover, the chemically bonded MNPs could induce the originally disordered small molecular PEO- b-PS to form ordered cylindrical and lamellar structure, as evidenced by TEM and GISAXS, leading to sub-10-nm nanostructures of copolymer in the thin film state.

  13. Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.

    Science.gov (United States)

    Paydavosi, Sarah; Aidala, Katherine E; Brown, Patrick R; Hashemi, Pouya; Supran, Geoffrey J; Osedach, Timothy P; Hoyt, Judy L; Bulović, Vladimir

    2012-03-14

    Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells. © 2012 American Chemical Society

  14. Thin films of molecular materials synthesized from C32H20N10M (M Co, Pb, Fe): Film formation, electrical and optical properties

    International Nuclear Information System (INIS)

    Rodriguez, A.; Sanchez Vergara, M.E.; Garcia Montalvo, V.; Ortiz, A.; Alvarez, J.R.

    2010-01-01

    In this work, the synthesis of molecular materials formed from metallic phthalocyanines and 1,4-phenylenediamine is reported. The powder and thin film (∼80-115 nm thickness) samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The morphology of the deposited films was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and their optical and electrical properties were studied as well. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200-1200 nm. The absorption spectra recorded in the UV-vis region for the deposited samples showed two bands, namely the Q and Soret bands. The optical activation energy was calculated and found to be 3.41 eV for the material with cobalt, 3.34 eV for the material including lead and 3.5 eV for the material with iron. The effect of temperature on conductivity was measured for the thin films and the corresponding conduction processes are discussed in this work.

  15. Polymer friction Molecular Dynamics

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

  16. A molecular theory of chemically modified electrodes with self-assembled redox polyelectrolye thin films: Reversible cyclic voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Tagliazucchi, Mario; Calvo, Ernesto J. [INQUIMAE, DQIAyQF Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Szleifer, Igal [Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2008-10-01

    A molecular theory of chemically modified electrodes is applied to study redox polyelectroyte modified electrodes. The molecular approach explicitly includes the size, shape, charge distribution, and conformations of all of the molecular species in the system as well as the chemical equilibria (redox and acid-base) and intermolecular interactions. An osmium pyridine-bipyridine complex covalently bound to poly(allyl-amine) backbone (PAH-Os) adsorbed onto mercapto-propane sulfonate (MPS) thiolated gold electrode is described. The potential and electrolyte composition dependent redox and nonredox capacitance can be calculated with the molecular theory in very good agreement with voltammetric experiments under reversible conditions without the use of freely adjustable parameter. Unlike existing phenomenological models the theory links the electrochemical behavior with the structure of the polymer layer. The theory predicts a highly inhomogeneous distribution of acid-base and redox states that strongly couples with the spatial arrangement of the molecular species in the nanometric redox film. (author)

  17. Frequency-dependent squeeze-amplitude attenuation and squeeze-angle rotation by electromagnetically induced transparency for gravitational-wave interferometers

    International Nuclear Information System (INIS)

    Mikhailov, Eugeniy E.; Goda, Keisuke; Corbitt, Thomas; Mavalvala, Nergis

    2006-01-01

    We study the effects of frequency-dependent squeeze-amplitude attenuation and squeeze-angle rotation by electromagnetically induced transparency (EIT) on gravitational-wave (GW) interferometers. We propose the use of low-pass, bandpass, and high-pass EIT filters, an S-shaped EIT filter, and an intracavity EIT filter to generate frequency-dependent squeezing for injection into the antisymmetric port of GW interferometers. We find that the EIT filters have several advantages over the previous filter designs with regard to optical losses, compactness, and the tunability of the filter linewidth

  18. A Monte Carlo Simulation approach for the modeling of free-molecule squeeze-film damping of flexible microresonators

    KAUST Repository

    Leung, Roger; Cheung, Howard; Gang, Hong; Ye, Wenjing

    2010-01-01

    Squeeze-film damping on microresonators is a significant damping source even when the surrounding gas is highly rarefied. This article presents a general modeling approach based on Monte Carlo (MC) simulations for the prediction of squeeze

  19. Optimal unambiguous comparison of two unknown squeezed vacua

    International Nuclear Information System (INIS)

    Olivares, Stefano; Paris, Matteo G. A.; Sedlak, Michal; Rapsan, Peter; Busek, Vladimir

    2011-01-01

    We propose a scheme for the unambiguous state comparison (USC) of two unknown squeezed vacuum states of the electromagnetic field. Our setup is based on linear optical elements and photon-number detectors, and it achieves optimal USC in an ideal case of unit quantum efficiency. In realistic conditions, i.e., for nonunit quantum efficiency of photodetectors, we evaluate the probability of getting an ambiguous result as well as the reliability of the scheme, thus showing its robustness in comparison to previous proposals.

  20. Oscillatory squeeze flow for the study of linear viscoelastic behavior

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole

    2016-01-01

    of molten polymers and suspensions. The principal advantage of squeeze flow rheometer over rotational devices is the simplicity of the apparatus. It has no air bearing and is much less expensive and easier to use. Accuracy may be somewhat reduced, but for quality control purposes, it could be quite useful....... It might also find application as the central component of a high-throughput rheometer for evaluating experimental materials. The deformation is not simple shear, but equations have been derived to show that the oscillatory compressive (normal) force that is measured can serve as a basis for calculating...

  1. Lipid corralling and poloxamer squeeze-out in membranes

    DEFF Research Database (Denmark)

    Wu, G.H.; Majewski, J.; Ege, C.

    2004-01-01

    Using x-ray scattering measurements we have quantitatively determined the effect of poloxamer 188 (P188), a polymer known to seal damaged membranes, on the structure of lipid monolayers. P188 selectively inserts into low lipid-density regions of the membrane and "corrals" lipid molecules to pack...... tightly, leading to unexpected Bragg peaks at low nominal lipid density and inducing lipid/poloxamer phase separation. At tighter lipid packing, the once inserted P188 is squeezed out, allowing the poloxamer to gracefully exit when the membrane integrity is restored....

  2. Light squeezing through arbitrarily shaped plasmonic channels and sharp bends

    International Nuclear Information System (INIS)

    Alu, Andrea; Engheta, Nader

    2008-01-01

    We propose a mechanism for optical energy squeezing and anomalous light transmission through arbitrarily-shaped plasmonic ultranarrow channels and bends connecting two larger plasmonic metal-insulator-metal waveguides. It is shown how a proper design of subwavelength optical channels at cutoff, patterned by plasmonic implants and connecting larger plasmonic waveguides, may allow enhanced resonant transmission inspired by the anomalous properties of epsilon-near-zero (ENZ) metamaterials. The resonant transmission is shown to be only weakly dependent on the channel length and its specific geometry, such as possible presence of abruptions and bends

  3. Analysis of an Electrostatic MEMS Squeeze-film Drop Ejector

    Directory of Open Access Journals (Sweden)

    Edward P. Furlani

    2009-10-01

    Full Text Available We present an analysis of an electrostatic drop-on-demand MEMS fluid ejector. The ejector consists of a microfluidic chamber with a piston that is suspended a few microns beneath a nozzle plate. A drop is ejected when a voltage is applied between the orifice plate and the piston. This produces an electrostatic force that moves the piston towards the nozzle. The moving piston generates a squeeze-film pressure distribution that causes drop ejection. We discuss the operating physics of the ejector and present a lumped-element model for predicting its performance. We calibrate the model using coupled structural-fluidic CFD analysis.

  4. Colliding During the Squeeze and β* Levelling in the LHC

    CERN Document Server

    Buffat, X; Lamont, M; Pieloni, T; Redaelli, S; Wenninger, J

    2013-01-01

    While significantly more complicated in term of operation, bringing the beams into collisions prior to the β squeeze rather than after presents some advantages. Indeed, the large tune spread arising from the non-linearity of head-on beam-beam interactions is profitable, as it can damp impedance driven instabilities much more efficiently than external non-linearity such as octupoles. Moreover, this operation allows to level the luminosity in the case when the peak luminosity is too high for the experiments. Operational issues are discussed and experimental results from the LHC are presented.

  5. Quadrature measurements of a bright squeezed state via sideband swapping

    DEFF Research Database (Denmark)

    Schneider, J.; Glockl, O.; Leuchs, G.

    2009-01-01

    The measurement of an arbitrary quadrature of a bright quantum state of light is a commonly requested action in many quantum information protocols, but it is experimentally challenging with previously proposed schemes. We suggest that the quadrature be measured at a specific sideband frequency...... of a bright quantum state by transferring the sideband modes under interrogation to a vacuum state and subsequently measuring the quadrature via homodyne detection. The scheme is implemented experimentally, and it is successfully tested with a bright squeezed state of light....

  6. All-fibre source of amplitude squeezed light pulses

    Energy Technology Data Exchange (ETDEWEB)

    Meissner, Markus; Marquardt, Christoph; Heersink, Joel; Gaber, Tobias; Wietfeld, Andre; Leuchs, Gerd; Andersen, Ulrik L [Institut fuer Optik, Information und Photonik, Max-Planck Forschungsgruppe Universitaet Erlangen-Nuernberg, Staudtstrasse 7/B2, 91058, Erlangen (Germany)

    2004-08-01

    An all-fibre source of amplitude squeezed solitons utilizing the self-phase modulation in an asymmetric Sagnac interferometer is experimentally demonstrated. The asymmetry of the interferometer is passively controlled by an integrated fibre coupler, allowing for the optimization of the noise reduction. We have carefully studied the dependence of the amplitude noise on the asymmetry and the power launched into the Sagnac interferometer. Qualitatively, we find good agreement between the experimental results, a semi-classical theory and earlier numerical calculations (Schmitt et al 1998 Phys. Rev. Lett. 81 2446). The stability and flexibility of this all-fibre source makes it particularly well suited to applications in quantum information science.

  7. Variance squeezing and entanglement of the XX central spin model

    International Nuclear Information System (INIS)

    El-Orany, Faisal A A; Abdalla, M Sebawe

    2011-01-01

    In this paper, we study the quantum properties for a system that consists of a central atom interacting with surrounding spins through the Heisenberg XX couplings of equal strength. Employing the Heisenberg equations of motion we manage to derive an exact solution for the dynamical operators. We consider that the central atom and its surroundings are initially prepared in the excited state and in the coherent spin state, respectively. For this system, we investigate the evolution of variance squeezing and entanglement. The nonclassical effects have been remarked in the behavior of all components of the system. The atomic variance can exhibit revival-collapse phenomenon based on the value of the detuning parameter.

  8. Normalized Excited Squeezed Vacuum State and Its Applications

    International Nuclear Information System (INIS)

    Meng Xiangguo; Wang Jisuo; Liang Baolong

    2007-01-01

    By using the intermediate coordinate-momentum representation in quantum optics and generating function for the normalization of the excited squeezed vacuum state (ESVS), the normalized ESVS is obtained. We find that its normalization constants obtained via two new methods are uniform and a new form which is different from the result obtained by Zhang and Fan [Phys. Lett. A 165 (1992) 14]. By virtue of the normalization constant of the ESVS and the intermediate coordinate-momentum representation, the tomogram of the normalized ESVS and some useful formulae are derived.

  9. Variance squeezing and entanglement of the XX central spin model

    Energy Technology Data Exchange (ETDEWEB)

    El-Orany, Faisal A A [Department of Mathematics and Computer Science, Faculty of Science, Suez Canal University, Ismailia (Egypt); Abdalla, M Sebawe, E-mail: m.sebaweh@physics.org [Mathematics Department, College of Science, King Saud University PO Box 2455, Riyadh 11451 (Saudi Arabia)

    2011-01-21

    In this paper, we study the quantum properties for a system that consists of a central atom interacting with surrounding spins through the Heisenberg XX couplings of equal strength. Employing the Heisenberg equations of motion we manage to derive an exact solution for the dynamical operators. We consider that the central atom and its surroundings are initially prepared in the excited state and in the coherent spin state, respectively. For this system, we investigate the evolution of variance squeezing and entanglement. The nonclassical effects have been remarked in the behavior of all components of the system. The atomic variance can exhibit revival-collapse phenomenon based on the value of the detuning parameter.

  10. Squeezing of higher order Hermite-Gauss modes

    DEFF Research Database (Denmark)

    Lassen, Mikael Østergaard

    2008-01-01

    The present paper gives an overview of the experimental generation of squeezing in higher order Hermite-Gaussian modes with an optical parametric ampli¯er (OPA). This work was awarded with The European Optical Society (EOS) price 2007. The purpose of the prize is to encourage a European dimension...... in research in pure and applied optics. The EOS prize is awarded based on the selection criteria of high professionalism, academic and technical quality. Following the EOS Prize rules, the conditions for eligibility are that the work was performed in Europe and that it is published under the auspices...

  11. On irreversible evolutions of two-level systems approaching coherent and squeezed states

    International Nuclear Information System (INIS)

    Jurco, B.; Tolar, J.

    1988-01-01

    The concepts of completely positive quantum dynamical semigroups and SU(2)-related generalized coherence and squeezing are used to investigate conditions for Markovian evolutions leading to coherent, intelligent, minimum-uncertainty and squeezed asymptotic stationary states in a 2-level system. (author). 10 refs

  12. New Three-Mode Squeezing Operators Gained via Tripartite Entangled State Representation

    International Nuclear Information System (INIS)

    Jiang Nianquan; Fan Hongyi

    2008-01-01

    We show that the Agarwal-Simon representation of single-mode squeezed states can be generalized to find new form of three-mode squeezed states. We use the tripartite entangled state representations |p,y,z> and |x,u,v> to realize this goal.

  13. SU(2) and SU(1,1) squeezing of interacting radiation modes

    International Nuclear Information System (INIS)

    Abdalla Sebawe, M.; Faisal El-Orany, A.A.; Perina, J.

    2000-01-01

    In this communication we discuss SU(1,1) and SU(2) squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated. (authors)

  14. Measurement Induced Enhancement of Squeezing in Nondegenerate Two-Photon Jaynes-Cummings Model

    International Nuclear Information System (INIS)

    Ye Saiyun

    2006-01-01

    Squeezing properties in the nondegenerate two-photon Jaynes-Cummings model are investigated. The effects of direct selective atomic measurement and the application of the classical field followed by atomic measurement are analyzed. Different values of the parameters of the classical field are taken into account. It is found that the field squeezing can be enhanced by measurement.

  15. Nonlinear modeling and testing of magneto-rheological fluids in low shear rate squeezing flows

    International Nuclear Information System (INIS)

    Farjoud, Alireza; Ahmadian, Mehdi; Craft, Michael; Mahmoodi, Nima; Zhang, Xinjie

    2011-01-01

    A novel analytical investigation of magneto-rheological (MR) fluids in squeezing flows is performed and the results are validated with experimental test data. The squeeze flow of MR fluids has recently been of great interest to researchers. This is due to the large force capacity of MR fluids in squeeze mode compared to other modes (valve and shear modes), which makes the squeeze mode appropriate for a wide variety of applications such as impact dampers and engine mounts. Tested MR fluids were capable of providing a large range of controllable force along a short stroke in squeeze mode. A mathematical model was developed using perturbation techniques to predict closed-form solutions for velocity field, shear rate distribution, pressure distribution and squeeze force. Therefore, the obtained solutions greatly help with the design process of intelligent devices that use MR fluids in squeeze mode. The mathematical model also reduces the need for complicated and computationally expensive numerical simulations. The analytical results are validated by performing experimental tests on a novel MR device called an 'MR pouch' in an MR squeeze mode rheometer, both designed and built at CVeSS

  16. Experimental evidence for Raman-induced limits to efficient squeezing in optical fibers

    DEFF Research Database (Denmark)

    Dong, R.; Heersink, J.; Corney, J.

    2008-01-01

    We report new experiments on polarization squeezing using ultrashort photonic pulses in a single pass of a birefringent fiber. We measure what is to our knowledge a record squeezing of -6.8 +/- 0.3 dB in optical fibers which when corrected for linear losses is -10.4 +/- 0.8 dB. The measured polar...

  17. Entanglements in P3HT and their influence on thin-film mechanical properties: Insights from molecular dynamics simulations

    KAUST Repository

    Tummala, Naga Rajesh; Risko, Chad; Bruner, Christopher; Dauskardt, Reinhold H.; Bredas, Jean-Luc

    2015-01-01

    Due to their inherent mechanical flexibility and stretchability, organic-based electronic devices have garnered a great deal of academic and industrial interest. Here, molecular-dynamics simulations are used to examine the molecular-scale details that govern the relationships among molecular weight, chain entanglement, persistence length, and the elastic characteristics of the widely studied π-conjugated polymer poly-(3-hexyl thiophene), P3HT. Oligomers containing at least 50 monomer units are required in the simulations to observe elastic behavior in P3HT, while much longer chains are required to ensure description of appropriate levels of entanglement: only when the molecular weight is greater than 50 kDa, that is, oligomers with approximately 400 monomer units, is truly entangled behavior observed. Interestingly, results from primitive path analysis of amorphous P3HT matches well with the observed onsets of inter-chain excitonic coherence with increased molecular weight. The simulations also indicate that the P3HT modulus saturates at 1.6 GPa for chain lengths of 50–100 monomers, a result that compares well with experimental results. This work highlights the care that needs to be taken to accurately model P3HT morphologies in relation to experimental measurements. © 2015 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015

  18. Entanglements in P3HT and their influence on thin-film mechanical properties: Insights from molecular dynamics simulations

    KAUST Repository

    Tummala, Naga Rajesh

    2015-04-01

    Due to their inherent mechanical flexibility and stretchability, organic-based electronic devices have garnered a great deal of academic and industrial interest. Here, molecular-dynamics simulations are used to examine the molecular-scale details that govern the relationships among molecular weight, chain entanglement, persistence length, and the elastic characteristics of the widely studied π-conjugated polymer poly-(3-hexyl thiophene), P3HT. Oligomers containing at least 50 monomer units are required in the simulations to observe elastic behavior in P3HT, while much longer chains are required to ensure description of appropriate levels of entanglement: only when the molecular weight is greater than 50 kDa, that is, oligomers with approximately 400 monomer units, is truly entangled behavior observed. Interestingly, results from primitive path analysis of amorphous P3HT matches well with the observed onsets of inter-chain excitonic coherence with increased molecular weight. The simulations also indicate that the P3HT modulus saturates at 1.6 GPa for chain lengths of 50–100 monomers, a result that compares well with experimental results. This work highlights the care that needs to be taken to accurately model P3HT morphologies in relation to experimental measurements. © 2015 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015

  19. Spin squeezing as an indicator of quantum chaos in the Dicke model.

    Science.gov (United States)

    Song, Lijun; Yan, Dong; Ma, Jian; Wang, Xiaoguang

    2009-04-01

    We study spin squeezing, an intrinsic quantum property, in the Dicke model without the rotating-wave approximation. We show that the spin squeezing can reveal the underlying chaotic and regular structures in phase space given by a Poincaré section, namely, it acts as an indicator of quantum chaos. Spin squeezing vanishes after a very short time for an initial coherent state centered in a chaotic region, whereas it persists over a longer time for the coherent state centered in a regular region of the phase space. We also study the distribution of the mean spin directions when quantum dynamics takes place. Finally, we discuss relations among spin squeezing, bosonic quadrature squeezing, and two-qubit entanglement in the dynamical processes.

  20. First beam test of a combined ramp and squeeze at LHC

    CERN Document Server

    Wenninger, Jorg; Coello De Portugal - Martinez Vazquez, Jaime Maria; Gorzawski, Arkadiusz; Redaelli, Stefano; Schaumann, Michaela; Solfaroli Camillocci, Matteo; CERN. Geneva. ATS Department

    2015-01-01

    With increasing maturity of LHC operation it is possible to envisage more complex beam manipulations. At the same time operational efficiency receives increasing attention. So far ramping the beams to their target energy and squeezing the beams to smaller or higher beta are decoupled at the LHC. (De-)squeezing is always performed at the target energy, currently 6.5 TeV. Studies to combine the ramp and squeeze processes have been made for the LHC since 2011, but so far no experimental test with beam had ever performed. This note describes the first machine experiment with beam aiming at validating the combination of ramp and squeeze, the so-called combined ramp and squeeze (CRS).

  1. Influence of the virtual photon field on the squeezing properties of an atom laser

    International Nuclear Information System (INIS)

    Jian-Gang, Zhao; Chang-Yong, Sun; Ling-Hua, Wen; Bao-Long, Liang

    2009-01-01

    This paper investigates the squeezing properties of an atom laser without rotating-wave approximation in the system of a binomial states field interacting with a two-level atomic Bose–Einstein condensate. It discusses the influences of atomic eigenfrequency, the interaction intensity between the optical field and atoms, parameter of the binomial states field and virtual photon field on the squeezing properties. The results show that two quadrature components of an atom laser can be squeezed periodically. The duration and the degree of squeezing an atom laser have something to do with the atomic eigenfrequency and the parameter of the binomial states field, respectively. The collapse and revival frequency of atom laser fluctuation depends on the interaction intensity between the optical field and atoms. The effect of the virtual photon field deepens the depth of squeezing an atom laser

  2. Generation of higher-order squeezing of quantum electromagnetic fields by degenerate four-wave mixing and other processes

    International Nuclear Information System (INIS)

    Li Xizeng; Shan Ying; Mandel, L.

    1988-11-01

    It is found that the field of the combined mode of the probe wave and the phase-conjugate wave in the process of degenerate four-wave mixing exhibits higher-order squeezing to all even order. The degree of squeezing increases with the order N, and the higher-order squeeze parameter q N may approach -1. (author). 3 refs, 2 figs

  3. Atom-number squeezing and bipartite entanglement of two-component Bose-Einstein condensates: analytical results

    Energy Technology Data Exchange (ETDEWEB)

    Jin, G R; Wang, X W; Li, D; Lu, Y W, E-mail: grjin@bjtu.edu.c [Department of Physics, Beijing Jiaotong University, Beijing 100044 (China)

    2010-02-28

    We investigate spin dynamics of a two-component Bose-Einstein condensate with weak Josephson coupling. Analytical expressions of atom-number squeezing and bipartite entanglement are presented for atom-atom repulsive interactions. For attractive interactions, there is no number squeezing; however, the squeezing parameter is still useful to recognize the appearance of Schroedinger's cat state.

  4. Damping of the radial impulsive motion of LMFBR core components separated by fluid squeeze films

    International Nuclear Information System (INIS)

    Liebe, R.; Zehlein, H.

    1977-01-01

    The core deformation of a liquid metal cooled fast breeder reactor (LMFBR) due to local pressure propagation from rapid energy releases is a complex three-dimensional fluid-structure-interaction problem. High pressure transients of short duration cause structural deformation of the closely spaced fuel elements, which are surrounded by the flowing coolant. Corresponding relative displacements give rise to squeezing fluid motion in the thin layers between the subassemblies. Therefore significant backpressures are produced and the resulting time and space dependent fluid forces are acting on the structure as additional non-conservative external loads. Realistic LMFBR safety analysis of several clustered fuel elements have to account for such flow induced forces. Several idealized models have been proposed to study some aspects of the complex problem. As part of the core mechanics activities at GfK Karlsruhe this paper describes two fluid flow models (model A, model B), which are shown to be suitable for physically coupled fluid-structure analyses. Important assumptions are discussed in both cases and basic equations are derived for one- and two-dimensional incompressible flow fields. The interface of corresponing computer codes FLUF (model A) and FLOWAX (model B) with structural dynamics programs is outlined. Finally fluid-structure interaction problems relevant to LMFBR design are analyzed; parametric studies indicate a significant cushioning effect, energy dissipation and a strongly nonlinear as well as timedependent damping of the structural response. (Auth.)

  5. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

    International Nuclear Information System (INIS)

    Vidovic, Z.

    1997-06-01

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  6. Growth and characterization of β-Ga2O3 thin films by molecular beam epitaxy for deep-UV photodetectors

    Science.gov (United States)

    Ghose, Susmita; Rahman, Shafiqur; Hong, Liang; Rojas-Ramirez, Juan Salvador; Jin, Hanbyul; Park, Kibog; Klie, Robert; Droopad, Ravi

    2017-09-01

    The growth of high quality epitaxial beta-gallium oxide (β-Ga2O3) using a compound source by molecular beam epitaxy has been demonstrated on c-plane sapphire (Al2O3) substrates. The compound source provides oxidized gallium molecules in addition to oxygen when heated from an iridium crucible in a high temperature effusion cell enabling a lower heat of formation for the growth of Ga2O3, resulting in a more efficient growth process. This source also enabled the growth of crystalline β-Ga2O3 without the need for additional oxygen. The influence of the substrate temperatures on the crystal structure and quality, chemical bonding, surface morphology, and optical properties has been systematically evaluated by x-ray diffraction, scanning transmission electron microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, spectroscopic ellipsometry, and UV-vis spectroscopy. Under optimized growth conditions, all films exhibited pure (" separators="|2 ¯01 ) oriented β-Ga2O3 thin films with six-fold rotational symmetry when grown on a sapphire substrate. The thin films demonstrated significant absorption in the deep-ultraviolet (UV) region with an optical bandgap around 5.0 eV and a refractive index of 1.9. A deep-UV photodetector fabricated on the high quality β-Ga2O3 thin film exhibits high resistance and small dark current (4.25 nA) with expected photoresponse for 254 nm UV light irradiation suggesting that the material grown using the compound source is a potential candidate for deep-ultraviolet photodetectors.

  7. Accurate Molecular Orientation Analysis Using Infrared p-Polarized Multiple-Angle Incidence Resolution Spectrometry (pMAIRS) Considering the Refractive Index of the Thin Film Sample.

    Science.gov (United States)

    Shioya, Nobutaka; Shimoaka, Takafumi; Murdey, Richard; Hasegawa, Takeshi

    2017-06-01

    Infrared (IR) p-polarized multiple-angle incidence resolution spectrometry (pMAIRS) is a powerful tool for analyzing the molecular orientation in an organic thin film. In particular, pMAIRS works powerfully for a thin film with a highly rough surface irrespective of degree of the crystallinity. Recently, the optimal experimental condition has comprehensively been revealed, with which the accuracy of the analytical results has largely been improved. Regardless, some unresolved matters still remain. A structurally isotropic sample, for example, yields different peak intensities in the in-plane and out-of-plane spectra. In the present study, this effect is shown to be due to the refractive index of the sample film and a correction factor has been developed using rigorous theoretical methods. As a result, with the use of the correction factor, organic materials having atypical refractive indices such as perfluoroalkyl compounds ( n = 1.35) and fullerene ( n = 1.83) can be analyzed with high accuracy comparable to a compound having a normal refractive index of approximately 1.55. With this improved technique, we are also ready for discriminating an isotropic structure from an oriented sample having the magic angle of 54.7°.

  8. Structural, Optical, and Electrical Characterization of β-Ga2O3 Thin Films Grown by Plasma-Assisted Molecular Beam Epitaxy Suitable for UV Sensing

    Directory of Open Access Journals (Sweden)

    Abraham Arias

    2018-01-01

    Full Text Available β-Ga2O3 thin films were grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The films were grown using an elemental gallium source and oxygen supplied by an RF plasma source. Reflection high-energy electron diffraction (RHEED was used to monitor the surface quality in real time. Both in situ RHEED and ex situ X-ray diffraction confirmed the formation of single crystal β-phase films with excellent crystallinity on c-plane sapphire. Spectroscopic ellipsometry was used to determine the film thicknesses, giving values in the 11.6–18.8 nm range and the refractive index dispersion curves. UV-Vis transmittance measurements revealed that strong absorption of β-Ga2O3 starts at ∼270 nm. Top metal contacts were deposited by thermal evaporation for I-V characterization, which has been carried out in dark, as well as under visible and UV light illumination. The optical and electrical measurements showed that the grown thin films of β-Ga2O3 are excellent candidates for deep-ultraviolet detection and sensing.

  9. Ab initio molecular dynamics model for density, elastic properties and short range order of Co-Fe-Ta-B metallic glass thin films

    International Nuclear Information System (INIS)

    Hostert, C; Music, D; Schneider, J M; Bednarcik, J; Keckes, J; Kapaklis, V; Hjörvarsson, B

    2011-01-01

    Density, elastic modulus and the pair distribution function of Co-Fe-Ta-B metallic glasses were obtained by ab initio molecular dynamics simulations and measured for sputtered thin films using x-ray reflectivity, nanoindentation and x-ray diffraction using high energy photons. The computationally obtained density of 8.19 g cm -3 for Co 43 Fe 20 Ta 5.5 B 31.5 and 8.42 g cm -3 for Co 45.5 Fe 24 Ta 6 B 24.5 , as well as the Young’s moduli of 273 and 251 GPa, respectively, are consistent with our experiments and literature data. These data, together with the good agreement between the theoretical and the experimental pair distribution functions, indicate that the model established here is useful to describe the density, elasticity and short range order of Co-Fe-Ta-B metallic glass thin films. Irrespective of the investigated variation in chemical composition, (Co, Fe)-B cluster formation and Co-Fe interactions are identified by density-of-states analysis. Strong bonds within the structural units and between the metallic species may give rise to the comparatively large stiffness. (paper)

  10. Nanoscale Trapping and Squeeze-Out of Confined Alkane Monolayers.

    Science.gov (United States)

    Gosvami, N N; O'Shea, S J

    2015-12-01

    We present combined force curve and conduction atomic force microscopy (AFM) data for the linear alkanes CnH2n+2 (n = 10, 12, 14, 16) confined between a gold-coated AFM tip and a graphite surface. Solvation layering is observed in the force curves for all liquids, and conduction AFM is used to study in detail the removal of the confined (mono)layer closest to the graphite surface. The squeeze-out behavior of the monolayer can be very different depending upon the temperature. Below the monolayer melting transition temperatures the molecules are in an ordered state on the graphite surface, and fast and complete removal of the confined molecules is observed. However, above the melting transition temperature the molecules are in a disordered state, and even at large applied pressure a few liquid molecules are trapped within the tip-sample contact zone. These findings are similar to a previous study for branched alkanes [ Gosvami Phys. Rev. Lett. 2008, 100, 076101 ], but the observation for the linear alkane homologue series demonstrates clearly the dependence of the squeeze-out and trapping on the state of the confined material.

  11. Heparin molecularly imprinted polymer thin flm on gold electrode by plasma-induced graft polymerization for label-free biosensor.

    Science.gov (United States)

    Orihara, Kouhei; Hikichi, Atsushi; Arita, Tomohiko; Muguruma, Hitoshi; Yoshimi, Yasuo

    2018-03-20

    Heparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique. The procedure of PIP is as follows: (i) Hexamethyldisiloxane plasma-polymerized thin film (PPF) as a pre-coating scaffold of active species for PIP (post-polymerization) is deposited on an Au electrode. (ii) The PPF/Au electrode is soaked in an water solution containing heparin (template), (2-(methacryloxy)-ethyl)trimethylammonium chloride acrylamide (functional monomer), acrylamide, and N,N-methylenebisacrylamide (crosslinker). Double bonds of monomer and crosslinker attacked by residually active species in pre-coating PPF cause radical chain reaction. Consequently, a growing polymer network of 20 nm thickness of PIP-MIP thin film is formed and grafted on the PPF/Au surface. (iii) The PIP-MIP/PPF/Au is washed by sodium chloride solution so as to remove the template. Non-imprinted polymer (NIP) is carried out like the same procedure without a template. The AFM, XPS, and QCM measurements show that the PIP process facilitates macromolecularly surface imprinting of template heparin where the template is easily removed and is rapidly rebound to PIP-MIP without a diffusional barrier. The heparin-PIP-MIP specifically binds to heparin compared with heparin analog chondroitin sulfate C (selective factor: 4.0) and a detectable range of heparin in the presence of CS (0.1 wt%) was 0.001-0.1 wt%. The PIP-NIP does not show selectivity between them. The evaluated binding kinetics are association (k a  = 350 ± 100 M -1  s -1

  12. Ultra-selective defect-free interfacially polymerized molecular sieve thin-film composite membranes for H2 purification

    KAUST Repository

    Ali, Zain

    2017-10-10

    Purification is a major bottleneck towards generating low-cost commercial hydrogen. In this work, inexpensive high-performance H2 separating membranes were fabricated by modifying the commercially successful interfacial polymerization production method for reverse osmosis membranes. Defect-free thin-film composite membranes were formed demonstrating unprecedented mixed-gas H2/CO2 selectivity of ≈ 50 at 140 °C with H2 permeance of 350 GPU, surpassing the permeance/selectivity upper bound of all known polymer membranes by a wide margin. The combination of exceptional separation performance and low manufacturing cost makes them excellent candidates for cost-effective hydrogen purification from steam cracking and similar processes.

  13. Large modulation of carrier transport by grain-boundary molecular packing and microstructure in organic thin films

    KAUST Repository

    Rivnay, Jonathan

    2009-11-08

    Solution-processable organic semiconductors are central to developing viable printed electronics, and performance comparable to that of amorphous silicon has been reported for films grown from soluble semiconductors. However, the seemingly desirable formation of large crystalline domains introduces grain boundaries, resulting in substantial device-to-device performance variations. Indeed, for films where the grain-boundary structure is random, a few unfavourable grain boundaries may dominate device performance. Here we isolate the effects of molecular-level structure at grain boundaries by engineering the microstructure of the high-performance n-type perylenediimide semiconductor PDI8-CN 2 and analyse their consequences for charge transport. A combination of advanced X-ray scattering, first-principles computation and transistor characterization applied to PDI8-CN 2 films reveals that grain-boundary orientation modulates carrier mobility by approximately two orders of magnitude. For PDI8-CN 2 we show that the molecular packing motif (that is, herringbone versus slip-stacked) plays a decisive part in grain-boundary-induced transport anisotropy. The results of this study provide important guidelines for designing device-optimized molecular semiconductors. © 2009 Macmillan Publishers Limited. All rights reserved.

  14. Exploring the squeezed three-point galaxy correlation function with generalized halo occupation distribution models

    Science.gov (United States)

    Yuan, Sihan; Eisenstein, Daniel J.; Garrison, Lehman H.

    2018-04-01

    We present the GeneRalized ANd Differentiable Halo Occupation Distribution (GRAND-HOD) routine that generalizes the standard 5 parameter halo occupation distribution model (HOD) with various halo-scale physics and assembly bias. We describe the methodology of 4 different generalizations: satellite distribution generalization, velocity bias, closest approach distance generalization, and assembly bias. We showcase the signatures of these generalizations in the 2-point correlation function (2PCF) and the squeezed 3-point correlation function (squeezed 3PCF). We identify generalized HOD prescriptions that are nearly degenerate in the projected 2PCF and demonstrate that these degeneracies are broken in the redshift-space anisotropic 2PCF and the squeezed 3PCF. We also discuss the possibility of identifying degeneracies in the anisotropic 2PCF and further demonstrate the extra constraining power of the squeezed 3PCF on galaxy-halo connection models. We find that within our current HOD framework, the anisotropic 2PCF can predict the squeezed 3PCF better than its statistical error. This implies that a discordant squeezed 3PCF measurement could falsify the particular HOD model space. Alternatively, it is possible that further generalizations of the HOD model would open opportunities for the squeezed 3PCF to provide novel parameter measurements. The GRAND-HOD Python package is publicly available at https://github.com/SandyYuan/GRAND-HOD.

  15. Impact of quantum–classical correspondence on entanglement enhancement by single-mode squeezing

    International Nuclear Information System (INIS)

    Joseph, Sijo K.; Chew, Lock Yue; Sanjuán, Miguel A.F.

    2014-01-01

    Quantum entanglement between two field modes can be achieved through the collective squeezing of the two respective modes. If single-mode squeezing is performed prior to such a two-mode squeezing, an enhancement of entanglement production can happen. Interestingly, the occurrence of this enhancement can be implicitly linked to the local classical dynamical behavior via the paradigm of quantum–classical correspondence. In particular, the entanglement generated through quantum chaos is found to be hardly enhanced by prior squeezing, since it is bounded by the saturation value of the maximally entangled Schmidt state with fixed energy. These results illustrate that entanglement enhancement via initial squeezing can serve as a useful indicator of quantum chaotic behaviour. - Highlights: • Continuous-variable entanglement is explored in the Pullen–Edmonds Hamiltonian. • The local phase-space structure and the entanglement enhancement are related. • Entanglement enhancement via squeezing is smaller for the chaotic orbit. • Entanglement enhancement via squeezing is higher for the regular orbit. • The magnitude of the entanglement enhancement serves as a quantum-chaos indicator

  16. Resonance fluorescence spectra of three-level atoms in a squeezed vacuum

    International Nuclear Information System (INIS)

    Ferguson, M.R.; Ficek, Z.; Dalton, B.J.

    1996-01-01

    The fluorescence field from one of the two allowed transitions in a three-level atom can sense squeezed fluctuations of a vacuum field coupled to the other transition. We examine the fluorescence spectra of strongly driven three-level atoms in Λ, V, and cascade configurations in which one of the two one-photon transitions is coupled to a finite-bandwidth squeezed vacuum field, when the bandwidth is much smaller than the difference in the atomic transition frequencies, though much larger than atomic decay rates and Rabi frequencies of the driving fields. The driving fields are on one-photon resonance, and the squeezed vacuum field is generated by a degenerate parameter oscillator. Details are only given for the Λ configuration. The extension to the V and cascade configurations is straightforward. We find that in all configurations the fluorescence spectra of the transition not coupled to the squeezed vacuum field are composed of five lines, one central and two pairs of sidebands, with intensities and widths strongly influenced by the squeezed vacuum field. However, only the central component and the outer sidebands exhibit a dependence on the squeezing phase. We also examine the fluorescence spectrum for the cascade configuration with a squeezed vacuum field on resonance with the two-photon transition between the ground and the most excited states and now generated by a nondegenerate parametric oscillator. In this case, where the squeezed vacuum field can be made coupled to both transitions, all spectral lines depend on the squeezing phase. The spectral features are explained in terms of the dressed-atom model of the system. We show that the coherent mixing of the atomic states by the strong driving fields modifies transition rates between the dressed states, which results in the selective phase dependence of the spectral features. copyright 1996 The American Physical Society

  17. Squeeze casting of aluminum alloy A380: Microstructure and tensile behavior

    Directory of Open Access Journals (Sweden)

    Li Fang

    2015-09-01

    Full Text Available A380 alloy with a relatively thick cross-section of 25 mm was squeeze cast using a hydraulic press with an applied pressure of 90 MPa. Microstructure and tensile properties of the squeeze cast A380 were characterized and evaluated in comparison with the die cast counterpart. Results show that the squeeze cast A380 possesses a porosity level much lower than the die cast alloy, which is disclosed by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength (UTS: 215.9 MPa and elongation (Ef: 5.4%, for the squeeze cast samples over those of the conventional high-pressure die cast part (UTS: 173.7 MPa, Ef: 1.0%. The analysis of tensile behavior shows that the squeeze cast A380 exhibits a high tensile toughness (8.5 MJ·m-3 and resilience (179.3 kJ·m-3 compared with the die cast alloy (toughness: 1.4 MJ·m-3, resilience: 140.6 kJ·m-3, despite that, during the onset of plastic deformation, the strain-hardening rate of the die cast specimen is higher than that of the squeeze cast specimens. The microstructure analyzed by the scanning electron microscopy (SEM shows that both the squeeze and die cast specimens contain the primary α-Al, Al2Cu, Al5FeSi phase and the eutectic Si phase. But, the Al2Cu phase present in the squeeze cast alloy is relatively large in size and quantity. The SEM fractography evidently reveals the ductile fracture features of the squeeze cast A380 alloy.

  18. Interactions of fast molecular ions traversing thin foils. The contribution from field ionized Rydberg atoms in measurements on convoy electrons

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1983-01-01

    Experiments with fast (MeV) molecular-ion beams offer many attractive possibilities for studying atomic collisions in solids. Of particular value in such experiments is the possibility of determining the force fields (primarily in the induced electric field) that surround ionic fragments traversing a solid. One has the opportunity to evaluate these fields not just at the fragments themselves (as one would, for example, in stopping-power measurements with monatomic projectiles) but in the spatial regions extending out to several Angstroms from the fragment positions. In this paper we give a brief introduction to the subject and present some recent results

  19. Comparison of acetate tape impression with squeezing versus skin scraping for the diagnosis of canine demodicosis.

    Science.gov (United States)

    Pereira, A V; Pereira, S A; Gremião, I D F; Campos, M P; Ferreira, A M R

    2012-11-01

    This study compared the sensitivity of acetate tape impression and skin squeezing with that of deep skin scraping for the diagnosis of demodicosis in dogs. Demodex canis was detected in 100% of acetate tape impressions obtained after skin squeezing and in 90% of deep skin scrapings. There was a significant difference (P < 0.001) between the techniques in the total number of mites detected. Acetate tape impression with skin squeezing was found to be more sensitive than deep skin scraping and is an alternative diagnostic method for canine demodicosis. © 2012 The Authors. Australian Veterinary Journal © 2012 Australian Veterinary Association.

  20. Effects of Velocity-Slip and Viscosity Variation in Squeeze Film Lubrication of Two Circular Plates

    Directory of Open Access Journals (Sweden)

    R.R. Rao

    2013-03-01

    Full Text Available A generalized form of Reynolds equation for two symmetrical surfaces is taken by considering velocity-slip at the bearing surfaces. This equation is applied to study the effects of velocity-slip and viscosity variation for the lubrication of squeeze films between two circular plates. Expressions for the load capacity and squeezing time obtained are also studied theoretically for various parameters. The load capacity and squeezing time decreases due to slip. They increase due to the presence of high viscous layer near the surface and decrease due to low viscous layer.

  1. Symplectic Group Representation of the Two-Mode Squeezing Operator in the Coherent State Basis

    Science.gov (United States)

    Fan, Hong-Yi; Chen, Jun-Hua

    2003-11-01

    We find that the coherent state projection operator representation of the two-mode squeezing operator constitutes a loyal group representation of symplectic group, which is a remarkable property of the coherent state. As a consequence, the resultant effect of successively applying two-mode squeezing operators are equivalent to a single squeezing in the two-mode Fock space. Generalization of this property to the 2n-mode case is also discussed. The project supported by National Natural Science Foundation of China under Grant No. 10575057

  2. Transparency or spectral narrowing for two-mode squeezing and entanglement

    International Nuclear Information System (INIS)

    Hu Xiangming; Oh, C. H.

    2011-01-01

    We analyze the nonadiabatic effects on the propagation of a two-mode squeezed field inside a medium of three-level Λ atoms that display the dark resonance. We identify the different effects for the two-mode quantum properties: (i) unconditional transparency for the sum squeezing and (ii) induced transparency or spectral narrowing for the difference squeezing depending on the relative widths of the initial correlation spectrum to the transparency window. These effects combine to induce transparency or spectrum narrowing for the bipartite entanglement. The potential applications range from quantum information to laser spectroscopy and frequency standards.

  3. Novel polymers as scale inhibitors for squeeze treatments

    Energy Technology Data Exchange (ETDEWEB)

    Duccini, Y.

    1996-12-31

    Squeeze treatments are increasingly important to recover oil from offshore platforms. During production deposition occurs and scale inhibitors are widely used. Different chemicals are already used to inhibit several scaling components, including BaSO{sub 4} which appears to be the major problem in wells of the North Sea. Phosphonates, polyacrylates, phosphinocarboxylates and polyvinylsulfonates are the leading products. All of them do not fulfill end users requirements, especially for harsh conditions such as low pHs, high barium and extreme temperatures and pressures. The paper describes new inhibitors both for standard conditions and harsh conditions which are overcoming most of the present drawbacks. In both sets of conditions, the results on performances, stability and absorption-desorption properties are presented. 7 refs., 9 figs., 4 tabs.

  4. Discrete coherent and squeezed states of many-qudit systems

    International Nuclear Information System (INIS)

    Klimov, Andrei B.; Munoz, Carlos; Sanchez-Soto, Luis L.

    2009-01-01

    We consider the phase space for n identical qudits (each one of dimension d, with d a primer number) as a grid of d n xd n points and use the finite Galois field GF(d n ) to label the corresponding axes. The associated displacement operators permit to define s-parametrized quasidistributions on this grid, with properties analogous to their continuous counterparts. These displacements allow also for the construction of finite coherent states, once a fiducial state is fixed. We take this reference as one eigenstate of the discrete Fourier transform and study the factorization properties of the resulting coherent states. We extend these ideas to include discrete squeezed states, and show their intriguing relation with entangled states of different qudits.

  5. Investigation of Squeeze Film Damping and Associated Loads

    DEFF Research Database (Denmark)

    Johansen, Per; Bender, Niels Christian; Hansen, Anders Hedegaard

    2017-01-01

    -viscous case. In consequence, this enable insights concerning the influence of piezo-viscosity on this damping effect. These models are used to investigate the loads, which the approaching surfaces experiences. Based on Hertzian theory, comparisons of impact loads and the dynamic squeeze loading are performed......Digital hydraulics have attracted attention towards fast switching valves and the increased focus on reliable fluid power entail that the lifetime of such valves is of great concern. An inherent feature of most valves for digital hydraulics is that of a mechanical end stop. Consequently...... is reviewed with a focus on maximum surface stresses. Using the Barus relation for viscosity-pressure dependency and different film geometries, the classical lubrication theory is applied together with the equation of motion, to obtain the gap height motion equation, both for the iso-viscous and piezo...

  6. Two-mode Gaussian density matrices and squeezing of photons

    International Nuclear Information System (INIS)

    Tucci, R.R.

    1992-01-01

    In this paper, the authors generalize to 2-mode states the 1-mode state results obtained in a previous paper. The authors study 2-mode Gaussian density matrices. The authors find a linear transformation which maps the two annihilation operators, one for each mode, into two new annihilation operators that are uncorrelated and unsqueezed. This allows the authors to express the density matrix as a product of two 1-mode density matrices. The authors find general conditions under which 2-mode Gaussian density matrices become pure states. Possible pure states include the 2-mode squeezed pure states commonly mentioned in the literature, plus other pure states never mentioned before. The authors discuss the entropy and thermodynamic laws (Second Law, Fundamental Equation, and Gibbs-Duhem Equation) for the 2-mode states being considered

  7. Enhancing photon squeezing one leviton at a time

    Science.gov (United States)

    Ferraro, D.; Ronetti, F.; Rech, J.; Jonckheere, T.; Sassetti, M.; Martin, T.

    2018-04-01

    A mesoscopic device in the simple tunnel junction or quantum point contact geometry emits microwaves with remarkable quantum properties, when subjected to a sinusoidal drive in the GHz range. In particular, single and two-photon squeezing as well as entanglement in the frequency domain have been reported. By revising the photoassisted noise analysis developed in the framework of electron quantum optics, we present a detailed comparison between the cosine drive case and other experimentally relevant periodic voltages such as rectangular and Lorentzian pulses. We show that the latter drive is the best candidate in order to enhance quantum features and purity of the outgoing single and two-photon states, a noteworthy result in a quantum information perspective.

  8. Accompanying growth and room-temperature ferromagnetism of η-Mn3N2 thin films by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Yu, Fengmei; Liu, Yajing; Yang, Mei; Wu, Shuxiang; Zhou, Wenqi; Li, Shuwei

    2013-01-01

    η-phase manganese nitride films have been grown on LaAlO 3 (100) and LaSrAlO 4 (001) substrates by using plasma-assisted molecular beam epitaxy. On the basis of reflective high energy electron diffraction, X-ray diffraction, and X-ray photoemission spectroscopy, it is confirmed that two types of η-Mn 3 N 2 with different lattice constants coexist in the films due to the lattice mismatches between the Mn 3 N 2 films and the substrates. Magnetic properties of the films were characterized by a superconducting quantum interference device magnetometer at room temperature. The Mn 3 N 2 films on LaAlO 3 substrate were found to have room-temperature ferromagnetism. Two potential interaction mechanisms are proposed regarding the origin of the observed ferromagnetism. - Highlights: ► The films of two types of η-Mn 3 N 2 have been grown by molecular beam epitaxy. ► Mn 3 N 2 A and Mn 3 N 2 B coexisted in the films on LaAlO 3 and LaSrAlO 4 . ► The room-temperature ferromagnetism of the Mn 3 N 2 films on LaAlO 3 was obtained

  9. Applications of quantum electro-optic control and squeezed light

    International Nuclear Information System (INIS)

    Lam, P.K.

    2000-01-01

    Full text: The control theory of electronic feedback or feedforward is a topic well understood by many scientists and engineers. With many of the modern equipment relying on automation and robotics, an understanding of this classical control theory is a common requisite for many technologists. In the field of optics, electronic control theory is also commonly used in many situations. From the temperature controlling of laser systems, the auto-alignment of optical elements, to the locking of optical resonators, all make use of electronic control theory in their operations. In this talk, we present the use the control theory in the context of quantum optics. In much the same as its classical counterpart, the 'quantum electro-optic' control loop consists simply of an optical beam splitter, a detector and an electro-optic modulator. This simple system, however, can offer many interesting applications when used in combination with nonclassical states of light. One well-known example of non-classical light is that of the squeezed state of light. A light beam is referred to as being amplitude 'squeezed' when its amplitude has less noise when compared to that of a coherent light state. In fact, the field fluctuation of such light states in some sense lower that the field fluctuation of the photonic vacuum state. Yet another interesting non-classical light state is the so-called 'Einstein-Podolsky-Rosen' entangled pair. This consists of two beams of light, each of which has properties that are highly dependent on each other. Using both the quantum electro-optic control loops and these light states, we demonstrate schemes which allow us to perform noiseless optical amplification, quantum non-demolition measurement and quantum teleportation. These schemes may be important building blocks to the realisation of future quantum communications and quantum information networks

  10. Optical and electrical properties of semiconducting BaSi2 thin films on Si substrates grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Morita, K.; Inomata, Y.; Suemasu, T.

    2006-01-01

    The electrical properties and optical absorption (OA) spectra of undoped BaSi 2 films grown by molecular beam epitaxy were investigated The electron density and mobility of BaSi 2 grown epitaxially on Si(111) were 5 x 10 15 cm -3 and 820 cm 2 /V.s at room temperature, respectively. The conduction-band discontinuity at the BaSi 2 /Si heterojunction was estimated to be 0.7 eV from the current-voltage characteristics of n-BaSi 2 /n-Si isotype diodes. OA spectra were measured on polycrystalline BaSi 2 films grown on transparent fused silica substrates with predeposited polycrystalline Si layer. The indirect absorption edge was derived to be 1.3 eV, and the optical absorption coefficient reached 10 5 cm -1 at 1.5 eV

  11. Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

    KAUST Repository

    Alcheikh, Nouha

    2016-05-06

    This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped-clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. © 2016 IOP Publishing Ltd.

  12. Molecular dynamics study on evaporation and condensation characteristics of thin film liquid Argon on nanostructured surface in nano-scale confinement

    Science.gov (United States)

    Hasan, Mohammad Nasim; Rabbi, Kazi Fazle; Sabah, Arefiny; Ahmed, Jannat; Kuri, Subrata Kumar; Rakibuzzaman, S. M.

    2017-06-01

    Investigation of Molecular level phase change phenomena are becoming important in heat and mass transfer research at a very high rate, driven both by the need to understand certain fundamental phenomena as well as by a plethora of new and forthcoming applications in the areas of micro- and nanotechnologies. Molecular dynamics simulation has been carried out to go through the evaporation and condensation characteristics of thin liquid argon film in Nano-scale confinement. In the present study, a cuboid system is modeled for understanding the Nano-scale physics of simultaneous evaporation and condensation. The cuboid system consists of hot and cold parallel platinum plates at the bottom and top ends. The fluid comprised of liquid argon film at the bottom plate and vapor argon in between liquid argon and upper plate of the domain. Three different simulation domains have been created here: (i) Both platinum plates are considered flat, (ii) Upper plate consisting of transverse slots of low height and (iii) Upper plate consisting of transverse slots of bigger height. Considering hydrophilic nature of top and bottom plates, two different high temperatures of the hot wall was set and an observation was made on normal and explosive vaporizations and their impacts on thermal transport. For all the structures, equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. Then the lower wall is set to two different temperatures like 110 K and 250 K for all three models to perform non-equilibrium molecular dynamics (NEMD). For vaporization, higher temperature of the hot wall led to faster transport of the liquid argon as a cluster moving from hot wall to cold wall. But excessive temperature causes explosive boiling which seems not good for heat transportation because of less phase change. In case of condensation, an observation was made which indicates that the nanostructured transverse slots facilitate condensation. Two factors affect the rate of

  13. Effects of thoracic squeezing on airway secretion removal in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Farkhondeh Yousefnia-Darzi

    2016-01-01

    Conclusions: According to the study findings, endotracheal suction with thoracic squeezing on expiration helps airway secretion discharge more than suction alone in patients on mechanical ventilators and can be used as an effective method.

  14. Energy eigenvalues and squeezing properties of general systems of coupled quantum anharmonic oscillators

    International Nuclear Information System (INIS)

    Chung, N. N.; Chew, L. Y.

    2007-01-01

    We have generalized the two-step approach to the solution of systems of N coupled quantum anharmonic oscillators. By using the squeezed vacuum state of each individual oscillator, we construct the tensor product state, and obtain the optimal squeezed vacuum product state through energy minimization. We then employ this optimal state and its associated bosonic operators to define a basis set to construct the Heisenberg matrix. The diagonalization of the matrix enables us to obtain the energy eigenvalues of the coupled oscillators. In particular, we have applied our formalism to determine the eigenenergies of systems of two coupled quantum anharmonic oscillators perturbed by a general polynomial potential, as well as three and four coupled systems. Furthermore, by performing a first-order perturbation analysis about the optimal squeezed vacuum product state, we have also examined into the squeezing properties of two coupled oscillator systems

  15. The squeezing properties in the Jaynes-Cummings model with arbitrary intensity-dependent coupling

    International Nuclear Information System (INIS)

    Rhui-Hua, X.; Dun-Huan, L.; Gong-Ou, X.

    1996-01-01

    It is studied the squeezing properties of the atom and the radiation field in arbitrary intensity-dependent-coupling Jaynes-Cummings model when it is restricted to the following initial condition: the atom in its coherent state and the field in the vacuum state. The influence of virtual-photon processes on the atomic squeezing predicted by the Jaynes-Cummings model (JCM) has been examined. The relationship between the field and atomic squeezing in the resonant multi-photon JCM has been discussed. The symmetry between the field and atomic squeezing (SFAS) has been exposed in the resonant vacuum one-photon JCM, and the influence of non-resonant interaction and virtual-photon processes on the SFAS has also been discussed

  16. Squeezing of a nanomechanical resonator by quantum nondemolition measurement and feedback

    Science.gov (United States)

    Ruskov, Rusko; Schwab, Keith; Korotkov, Alexander N.

    2005-06-01

    We analyze squeezing of the nanoresonator state produced by periodic measurement of position by a quantum point contact or a single-electron transistor. The mechanism of squeezing is the stroboscopic quantum nondemolition measurement generalized to the case of continuous measurement by a weakly coupled detector. The magnitude of squeezing is calculated for the harmonic and stroboscopic modulations of measurement, taking into account detector efficiency and nanoresonator quality factor. We also analyze the operation of the quantum feedback, which prevents fluctuations of the wave packet center due to measurement back-action. Verification of the squeezed state can be performed in almost the same way as its preparation; a similar procedure can also be used for the force detection with sensitivity beyond the standard quantum limit.

  17. Temperature and Pressure Evolution during Al Alloy Solidification at Different Squeeze Pressures

    International Nuclear Information System (INIS)

    Li, Junwen; Zhao, Haidong; Chen, Zhenming

    2015-01-01

    Squeeze casting is an advanced and near net-shape casting process, in which external high pressure is applied to solidifying castings. The castings are characterized with fine grains and good mechanical properties. In this study, a series of experiments were carried out to measure the temperature and pressure histories in cavity of Al-Si-Mg direct squeeze castings with different applied solidification pressures of 0.1, 50, 75, and 100 MPa. The evolution of the measured temperatures and pressures was compared and discussed. The effect of pressure change on formation of shrinkage defects was analyzed. Further the friction between the castings and dies during solidification was calculated. It is shown that the applied squeeze pressure has significant influence on the friction at die and casting interfaces, which affects the pressure evolution and transmission. The results could provide some benchmark data for future thermal-mechanics coupled modeling of squeeze castings. (paper)

  18. Investigation on the Yarn Squeezing Effect of Three Dimensional Full Five Directional Braided Composites

    Science.gov (United States)

    Hu, Long; Tao, Guoquan; Liu, Zhenguo; Wang, Yibo; Ya, Jixuan

    2018-04-01

    The influence of yarn squeezing effect on the geometric morphology and mechanical property of the three dimensional full five directional (3DF5D) braided composites is explored. Spatial path and cross-section shape of the yarns in the braided structure are characterized based on the micro computed tomography (micro CT) scanning images. The yarn distortion due to the squeezing effect is discussed and mathematical morphology of the yarn geometry is established. A new repeated unit cell (RUC) model of 3DF5D braided composites considering yarn squeezing effect is developed. Based on this model, mechanical properties of 3DF5D braided composites are analyzed. Good agreement is obtained between the predicted and experiment results. Moreover, the stress distribution of the new RUC model are compared with original RUC model, showing that the squeezing effect significantly increases the stress concentration level of the axial yarns.

  19. Control of segregation in squeeze cast Al-4.5Cu binary alloy

    Energy Technology Data Exchange (ETDEWEB)

    Durrant, G. [Oxford Univ. (United Kingdom). Dept. of Materials; Gallerneault, M. [Alcan International Ltd., Kingston, ON (Canada); Cantor, B. [Oxford Univ. (United Kingdom). Dept. of Materials

    1997-10-01

    The high pressure applied in squeeze casting allows Al alloys of wrought composition to be cast to near net-shape, although their long freezing range leads to the segregation of alloying elements. In this paper we present results on the squeeze casting and gravity casting of a model Al-4.5 wt%Cu alloy. Squeeze cast Al-4.5Cu has a normal segregation pattern with eutectic macrosegregates towards the centre of the billet, whereas gravity cast material has a typical inverse segregation pattern. Normal segregation in squeeze cast Al-4.5Cu is due to large temperature gradients during solidification. Segregation can be minimized by releasing the applied pressure during solidification to allow backflow of the interdendritic fluid, or by the addition of grain refiner to remove the large columnar dendritic growth structure. (orig.)

  20. Optimization of Squeeze Parameters and Modification of AlSi7Mg Alloy

    Directory of Open Access Journals (Sweden)

    Zyska A.

    2013-06-01

    Full Text Available The paper present the examination results concerning mechanical properties of castings made of AlSi7MG alloy in correlation both with the most significant squeeze casting parameters and with the modification treatment. Experiments were planned and held according to the 23 factorial design. The regression equations describing the influence of the squeeze pressure, the mould temperature, and the quantity of strontium modifier on the strength and elongation of the examined alloy were obtained. It was found that the main factor controlling the strength increase is the squeeze pressure, while the plasticity (A5 of the alloy is affected most advantageously by modification. The application of modification treatment in squeeze casting technology enables for production of the slab-type castings made of AlSi7Mg alloy exhibiting strength at the level of 230 MPa and elongation exceeding 14%.

  1. Non-zero temperature two-mode squeezing for time-dependent two-level systems

    International Nuclear Information System (INIS)

    Aliaga, J.; Gruver, J.L.; Proto, A.N.; Cerdeira, H.A.

    1994-01-01

    A Maximum Entropy Principle density matrix method, valid for systems with temperature different from zero, is presented making it possible two-mode squeezed states in two-level systems with relevant operators and Hamiltonian connected with O(3,2). A method which allows one to relate the appearance of squeezing to the relevant operators, included in order to define the density matrix of the system is given. (author). 14 refs, 1 fig

  2. Bright squeezed vacuum in a nonlinear interferometer: frequency/temporal Schmidt-mode description

    OpenAIRE

    Sharapova, P. R.; Tikhonova, O. V.; Lemieux, S.; Boyd, R. W.; Chekhova, M. V.

    2018-01-01

    Control over the spectral properties of the bright squeezed vacuum (BSV), a highly multimode non-classical macroscopic state of light that can be generated through high-gain parametric down conversion, is crucial for many applications. In particular, in several recent experiments BSV is generated in a strongly pumped SU(1,1) interferometer to achieve phase supersensitivity, perform broadband homodyne detection, or tailor the frequency spectrum of squeezed light. In this work, we present an an...

  3. Free-Space Squeezing Assists Perfectly Matched Layers in Simulations on a Tight Domain

    DEFF Research Database (Denmark)

    Shyroki, Dzmitry; Ivinskaya, Aliaksandra; Lavrinenko, Andrei

    2010-01-01

    outside the object, as in simulations of eigenmodes or scattering at a wavelength comparable to or larger than the object itself. Here, we show how, in addition to applying the perfectly matched layers (PMLs), outer free space can be squeezed to avoid cutting the evanescent field tails by the PMLs...... or computational domain borders. Adding the squeeze-transform layers to the standard PMLs requires no changes to the finite-difference algorithms....

  4. Effects of hydrophilic solvent and oxidation resistance post surface treatment on molecular structure and forward osmosis performance of polyamide thin-film composite (TFC) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Qibo; Xu, Yangyu [School of Environment, Tsinghua University, Beijing 100084 (China); Shen, Jianquan [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Haijun, E-mail: yanghj@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhou, Lu, E-mail: zhoulu@tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China)

    2015-11-30

    Graphical abstract: - Highlights: • NMP promotes swelling of polyamide, which enhances the TFC FO membrane water flux. • Electron-withdrawing carboxyl groups reduce the activity of polyamide molecules. • TMC and oxalic acid can improve the oxidation resistance properties of the FO membrane. • Oxalic acid and EDC improve the FO membrane separation performance significantly. - Abstract: In this article, novel hydrophilic solvents and antioxidants were used to post-treat aromatic polyamide thin-film composite (TFC) hollow fiber forward osmosis (FO) membranes. The effects of trimesoyl chloride (TMC) and oxalic acid on the structure of polyamide skin layer were investigated using ATR-FTIR and XPS analyses. Pure water flux and rejection of salts were detected using 2 M NaCl solution as draw solutions in FO processes. The results demonstrated that hydrophilic solvent N-methyl pyrrolidone (NMP) enhanced the water flux and kept a high salt retention of the TFC FO membrane. TMC and oxalic acid were both found to improve the oxidation resistance properties of the skin layer of TFC membrane because the electron-withdrawing carboxyl groups reduced the activity of polyamide molecular. The effects of the oxalic acid and carbodiimide on the molecular structures and the FO water flux of the polyamide TFC membranes were more marked than those of TMC. The novel TFC FO membrane treated by oxalic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) exhibited a high level of water flux (20.33 L m{sup −2} h{sup −1}), and the rates of salt rejection and salt reverse rejection were higher by 50% and 83%, respectively.

  5. Section thickness-dependent tensile properties of squeeze cast magnesium alloy AM60

    Directory of Open Access Journals (Sweden)

    Xuezhi Zhang

    2012-05-01

    Full Text Available The development of alternative casting processes is essential for the high demand of light weight magnesium components to be used in the automotive industry, which often contain different section thicknesses. Squeeze casting with its inherent advantages has been approved for the capability of minimizing the gas porosity in magnesium alloys. For advanced engineering design of light magnesium automotive applications, it is critical to understand the effect of section thickness on mechanical properties of squeeze cast magnesium alloys. In this study, magnesium alloy AM60 with different section thicknesses of 6, 10 and 20 mm squeeze cast under an applied pressure of 30 MPa was investigated. The prepared squeeze cast AM60 specimens were tensile tested at room termperature. The results indicate that the mechanical properties including yield strength (YS, ultimate tensile strength (UTS and elongation (A decrease with an increase in section thickness of squeeze cast AM60. The microstructure analysis shows that the improvement in the tensile behavior of squeeze cast AM60 is primarily attributed to the low-gas porosity level and fine grain strucuture which result from the variation of cooling rate of different section thickness. The numerical simulation (Magmasoft? was employed to determine the solidification rates of each step, and the simulated results show that the solidification rate of the alloy decreases with an increase in the section thickness. The computed solidification rates support the experimental observation on grain structural development.

  6. Study on fluidity of squeeze cast AZ91D magnesium alloy with different wall thicknesses

    Directory of Open Access Journals (Sweden)

    Chen Yun

    2014-03-01

    Full Text Available Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 mm, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 °C and 750 °C is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick (3 and 4 mm section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.

  7. Improved spin squeezing of an atomic ensemble through internal state control

    Science.gov (United States)

    Hemmer, Daniel; Montano, Enrique; Deutsch, Ivan; Jessen, Poul

    2016-05-01

    Squeezing of collective atomic spins is typically generated by quantum backaction from a QND measurement of the relevant spin component. In this scenario the degree of squeezing is determined by the measurement resolution relative to the quantum projection noise (QPN) of a spin coherent state (SCS). Greater squeezing can be achieved through optimization of the 3D geometry of probe and atom cloud, or by placing the atoms in an optical cavity. We explore here a complementary strategy that relies on quantum control of the large internal spin available in alkali atoms such as Cs. Using a combination of rf and uw magnetic fields, we coherently map the internal spins in our ensemble from the SCS (| f = 4, m = 4>) to a ``cat'' state which is an equal superposition of | f = 4, m = 4>and | f = 4, m = -4>. This increases QPN by a factor of 2 f = 8 relative to the SCS, and therefore the amount of backaction and spin-spin entanglement produced by our QND measurement. In a final step, squeezing generated in the cat state basis can be mapped back to the SCS basis, where it corresponds to increased squeezing of the physical spin. Our experiments suggest that up to 8dB of metrologically useful squeezing can be generated in this way, compared to ~ 3 dB in an otherwise identical experiment starting from a SCS.

  8. Is the price squeeze doctrine still viable in fully-regulated energy markets?

    International Nuclear Information System (INIS)

    Spiwak, L.J.

    1993-01-01

    Simply stated, a price squeeze occurs when a firm with monopoly power on the primary, or wholesale, level engages in a prolonged price increase that drives competitors out of the secondary, or retail level, and thereby extends its monopoly power to the secondary market. A price squeeze will not be found, however, for any short-term exercise in market power. Rather, because anticompetitive effects of a price squeeze are indirect, the price squeeze must last long enough and be severe enough to produce effects on actual or potential competition in the secondary market. In regulated electric industries, a price squeeze claim usually arises from the complex relationship between the supplier, the wholesale customer, the retail customer, and the federal and state regulators. The supplier sells electric power to both wholesale and retail customers. Wholesale transactions are regulated by federal regulators, and retail transactions are regulated at the state level. The wholesale customers in turn sell power to their retail customers. Over the last several years, there have been substantial developments in the application of the price squeeze doctrine to fully-regulated electric utilities. This article will examine the current developments in this area, and attempt to highlight the burdens potential litigants, both plaintiffs and defendants, must overcome to succeed

  9. Output field-quadrature measurements and squeezing in ultrastrong cavity-QED

    Science.gov (United States)

    Stassi, Roberto; Savasta, Salvatore; Garziano, Luigi; Spagnolo, Bernardo; Nori, Franco

    2016-12-01

    We study the squeezing of output quadratures of an electro-magnetic field escaping from a resonator coupled to a general quantum system with arbitrary interaction strengths. The generalized theoretical analysis of output squeezing proposed here is valid for all the interaction regimes of cavity-quantum electrodynamics: from the weak to the strong, ultrastrong, and deep coupling regimes. For coupling rates comparable or larger then the cavity resonance frequency, the standard input-output theory for optical cavities fails to calculate the variance of output field-quadratures and predicts a non-negligible amount of output squeezing, even if the system is in its ground state. Here we show that, for arbitrary interaction strength and for general cavity-embedded quantum systems, no squeezing can be found in the output-field quadratures if the system is in its ground state. We also apply the proposed theoretical approach to study the output squeezing produced by: (i) an artificial two-level atom embedded in a coherently-excited cavity; and (ii) a cascade-type three-level system interacting with a cavity field mode. In the latter case the output squeezing arises from the virtual photons of the atom-cavity dressed states. This work extends the possibility of predicting and analyzing the results of continuous-variable optical quantum-state tomography when optical resonators interact very strongly with other quantum systems.

  10. Fidelity of Quantum Teleportation for Single-Mode Squeezed State Light

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-Xiang; XIE Chang-De; PENG Kun-Chi

    2005-01-01

    @@ The fidelity of quantum teleportation of a single-mode squeezed state of light is calculated based on the general theory of quantum-mechanical measurement in the Schrodinger picture. It is shown that the criterion for the nonclassical state teleportation is different from that for coherent state. F = 1/2 is no longer the rigorous boundary between classical and quantum teleportation for a squeezed state of light. When the quantum entanglement of an Einstein-Podolsky-Rosen (EPR) beam used for teleportation and the parameters of the system are given,the fidelity depends on the squeezing of the input squeezed state. The higher the squeezing is, the smaller the fidelity is, and the lower the classical limitation of fidelity is. The dependence of the optimum gain for teleporting a squeezed vacuum state upon the EPR entanglement is also calculated. The results obtained provide important references for designing experimental systems of teleporting a non-classical state and judging the quality of the teleported quantum state.

  11. Collapse–revival of squeezing of two atoms in dissipative cavities

    International Nuclear Information System (INIS)

    Zou Hong-Mei; Fang Mao-Fa

    2016-01-01

    Based on the time-convolutionless master-equation approach, we investigate the squeezing dynamics of two atoms in dissipative cavities. We find that the atomic squeezing is related to initial atomic states, atom–cavity couplings, non-Markovian effects and resonant frequencies of an atom and its cavity. The results show that a collapse–revival phenomenon will occur in the atomic squeezing and this process is accompanied by the buildup and decay of entanglement between two atoms. Enhancing the atom–cavity coupling can increase the frequency of the collapse–revival of the atomic squeezing. The stronger the non-Markovian effect is, the more obvious the collapse–revival phenomenon is. In particular, if the atom–cavity coupling or the non-Markovian effect is very strong, the atomic squeezing will tend to a stably periodic oscillation in a long time. The oscillatory frequency of the atomic squeezing is dependent on the resonant frequency of the atom and its cavity. (paper)

  12. Combined computational-experimental approach to predict blood-brain barrier (BBB) permeation based on "green" salting-out thin layer chromatography supported by simple molecular descriptors.

    Science.gov (United States)

    Ciura, Krzesimir; Belka, Mariusz; Kawczak, Piotr; Bączek, Tomasz; Markuszewski, Michał J; Nowakowska, Joanna

    2017-09-05

    The objective of this paper is to build QSRR/QSAR model for predicting the blood-brain barrier (BBB) permeability. The obtained models are based on salting-out thin layer chromatography (SOTLC) constants and calculated molecular descriptors. Among chromatographic methods SOTLC was chosen, since the mobile phases are free of organic solvent. As consequences, there are less toxic, and have lower environmental impact compared to classical reserved phases liquid chromatography (RPLC). During the study three stationary phase silica gel, cellulose plates and neutral aluminum oxide were examined. The model set of solutes presents a wide range of log BB values, containing compounds which cross the BBB readily and molecules poorly distributed to the brain including drugs acting on the nervous system as well as peripheral acting drugs. Additionally, the comparison of three regression models: multiple linear regression (MLR), partial least-squares (PLS) and orthogonal partial least squares (OPLS) were performed. The designed QSRR/QSAR models could be useful to predict BBB of systematically synthesized newly compounds in the drug development pipeline and are attractive alternatives of time-consuming and demanding directed methods for log BB measurement. The study also shown that among several regression techniques, significant differences can be obtained in models performance, measured by R 2 and Q 2 , hence it is strongly suggested to evaluate all available options as MLR, PLS and OPLS. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Selective determination of semi-volatile thiophene compounds in water by molecularly imprinted polymer thin films with direct headspace gas chromatography sulfur chemiluminescence detection.

    Science.gov (United States)

    Hijazi, Hassan Y; Bottaro, Christina S

    2018-02-26

    Water-compatible molecularly imprinted polymer (MIP) thin films are coupled with headspace gas chromatography sulfur chemiluminescence detection (HS-GC-SCD) to create a new approach for the determination of trace concentrations of thiophene compounds in water samples. Thiophene compounds are persistent, typically petrogenic, organic pollutants of concern due to their potential for biomagnification and bioaccumulation, mutagenicity, and carcinogenicity in terrestrial and aquatic fauna. Identification and quantitation in water, particularly following oil spills, is a priority. Following adsorption of the thiophenes to the MIPs, the MIP-bound analytes are analyzed directly by HS-GC-SCD, with minimal sample manipulation and virtually no organic solvent. Calibration curves of spiked seawater were linear from 5 μg L -1 to 100 μg L -1 and limits of detection (LOD) were in the range of 0.24-0.82 μg L -1 . Low matrix effects were observed in the analysis of thiophene compounds in seawater making the method suitable for use in fresh and saline waters without modification. Acceptable reproducibility was obtained for analysis of thiophene compounds from spiked seawater samples at RSDs ≤7.0% (n = 3).

  14. Theoretical study of the transmission of low-energy (0-10 eV) electrons through thin-film organic molecular solids: benzene

    International Nuclear Information System (INIS)

    Goulet, T.; Jay-Gerin, J.-P.

    1986-01-01

    A theoretical study of the transmission of low-energy (0 to 10 eV) electrons incident from vacuum through thin-film organic molecular solids deposited on a cold metal substrate is presented and developed for the specific case of solid benzene. In essence, using a semiclassical description of electron transport in solids with an energy-independent scattering mean free path and assuming an isotropic electron scattering, the behavior of a penetrating electron in the film is simulated when a large number of scattering events are present. The good agreement between the calculated electron transmission spectra and those obtained experimentally indicates that our study provides a realistic description of the electron transport in the film, and accounts for the influence of the various electron-molecule scattering processes upon the energy dependence of the transmitted current. In particular, we show that the excitonic subionization energy losses are at the origin of the main structures of the observed electron transmission spectra. It is also shown that our study can successfully be used to estimate the probabilities of the various electron scattering processes which occur in the film, as well as the electron mean free path (l). For solid benzene, l is about 8 A in the considered electron energy range. (author)

  15. Epitaxial growth and magnetic properties of Fe4-xMnxN thin films grown on MgO(0 0 1) substrates by molecular beam epitaxy

    Science.gov (United States)

    Anzai, Akihito; Takata, Fumiya; Gushi, Toshiki; Toko, Kaoru; Suemasu, Takashi

    2018-05-01

    Epitaxial Fe4-xMnxN (x = 0, 1, 2, 3, and 4) thin films were successfully grown on MgO(0 0 1) single-crystal substrates by molecular beam epitaxy, and their crystalline qualities and magnetic properties were investigated. It was found that the lattice constants of Fe4-xMnxN obtained from X-ray diffraction measurement increased with the Mn content. The ratio of the perpendicular lattice constant c to the in-plane lattice constant a of Fe4-xMnxN was found to be about 0.99 at x ⩾ 2. The magnetic properties evaluated using a vibrating sample magnetometer at room temperature revealed that all of the Fe4-xMnxN films exhibited ferromagnetic behavior regardless of the value of x. In addition, the saturation magnetization decreased non-linearly as the Mn content increased. Finally, FeMn3N and Mn4N exhibited perpendicular anisotropy and their uniaxial magnetic anisotropy energies were 2.2 × 105 and 7.5 × 105 erg/cm3, respectively.

  16. Characterization of structural defects in SnSe2 thin films grown by molecular beam epitaxy on GaAs (111)B substrates

    Science.gov (United States)

    Tracy, Brian D.; Li, Xiang; Liu, Xinyu; Furdyna, Jacek; Dobrowolska, Margaret; Smith, David J.

    2016-11-01

    Tin selenide thin films have been grown by molecular beam epitaxy on GaAs (111)B substrates at a growth temperature of 150 °C, and a microstructural study has been carried out, primarily using the technique of transmission electron microscopy. The Se:Sn flux ratio during growth was systematically varied and found to have a strong impact on the resultant crystal structure and quality. Low flux ratios (Se:Sn=3:1) led to defective films consisting primarily of SnSe, whereas high flux ratios (Se:Sn>10:1) gave higher quality, single-phase SnSe2. The structure of the monoselenide films was found to be consistent with the Space Group Pnma with the epitaxial growth relationship of [011]SnSe// [ 1 1 bar 0 ] GaAs, while the diselenide films were consistent with the Space Group P 3 bar m1 , and had the epitaxial growth relationship [ 2 1 bar 1 bar 0 ]SnSe2// [ 1 1 bar 0 ] GaAs.

  17. Morphological and microstructural stability of N-polar InAlN thin films grown on free-standing GaN substrates by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Hardy, Matthew T.; Storm, David F.; Downey, Brian P.; Katzer, D. Scott; Meyer, David J.; McConkie, Thomas O.; Smith, David J.; Nepal, Neeraj

    2016-01-01

    The sensitivity of the surface morphology and microstructure of N-polar-oriented InAlN to variations in composition, temperature, and layer thickness for thin films grown by plasma-assisted molecular beam epitaxy (PAMBE) has been investigated. Lateral compositional inhomogeneity is present in N-rich InAlN films grown at low temperature, and phase segregation is exacerbated with increasing InN fraction. A smooth, step-flow surface morphology and elimination of compositional inhomogeneity can be achieved at a growth temperature 50 °C above the onset of In evaporation (650 °C). A GaN/AlN/GaN/200-nm InAlN heterostructure had a sheet charge density of 1.7 × 10 13  cm −2 and no degradation in mobility (1760 cm 2 /V s) relative to 15-nm-thick InAlN layers. Demonstration of thick-barrier high-electron-mobility transistors with good direct-current characteristics shows that device quality, thick InAlN layers can be successfully grown by PAMBE

  18. Morphological and microstructural stability of N-polar InAlN thin films grown on free-standing GaN substrates by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Matthew T., E-mail: matthew.hardy.ctr@nrl.navy.mil; Storm, David F.; Downey, Brian P.; Katzer, D. Scott; Meyer, David J. [Electronics Science and Technology Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington DC 20375 (United States); McConkie, Thomas O.; Smith, David J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Nepal, Neeraj [Sotera Defense Solutions, 2200 Defense Hwy Suite 405, Crofton, Maryland 21114 (United States)

    2016-03-15

    The sensitivity of the surface morphology and microstructure of N-polar-oriented InAlN to variations in composition, temperature, and layer thickness for thin films grown by plasma-assisted molecular beam epitaxy (PAMBE) has been investigated. Lateral compositional inhomogeneity is present in N-rich InAlN films grown at low temperature, and phase segregation is exacerbated with increasing InN fraction. A smooth, step-flow surface morphology and elimination of compositional inhomogeneity can be achieved at a growth temperature 50 °C above the onset of In evaporation (650 °C). A GaN/AlN/GaN/200-nm InAlN heterostructure had a sheet charge density of 1.7 × 10{sup 13 }cm{sup −2} and no degradation in mobility (1760 cm{sup 2}/V s) relative to 15-nm-thick InAlN layers. Demonstration of thick-barrier high-electron-mobility transistors with good direct-current characteristics shows that device quality, thick InAlN layers can be successfully grown by PAMBE.

  19. Structural properties of Bi{sub 2−x}Mn{sub x}Se{sub 3} thin films grown via molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Babakiray, Sercan; Johnson, Trent A.; Borisov, Pavel; Holcomb, Mikel B.; Lederman, David, E-mail: david.lederman@mail.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Marcus, Matthew A. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tarafder, Kartick [Department of Physics, BITS-Pilani Hyderabad Campus, Secunderabad, Andhra Pradesh 500078 (India)

    2015-07-28

    The effects of Mn doping on the structural properties of the topological insulator Bi{sub 2}Se{sub 3} in thin film form were studied in samples grown via molecular beam epitaxy. Extended x-ray absorption fine structure measurements, supported by density functional theory calculations, indicate that preferential incorporation occurs substitutionally in Bi sites across the entire film volume. This finding is consistent with x-ray diffraction measurements which show that the out of plane lattice constant expands while the in plane lattice constant contracts as the Mn concentration is increased. X-ray photoelectron spectroscopy indicates that the Mn valency is 2+ and that the Mn bonding is similar to that in MnSe. The expansion along the out of plane direction is most likely due to weakening of the Van der Waals interactions between adjacent Se planes. Transport measurements are consistent with this Mn{sup 2+} substitution of Bi sites if additional structural defects induced by this substitution are taken into account.

  20. Epitaxial properties of ZnO thin films on SrTiO3 substrates grown by laser molecular beam epitaxy

    International Nuclear Information System (INIS)

    Wei, X. H.; Li, Y. R.; Zhu, J.; Huang, W.; Zhang, Y.; Luo, W. B.; Ji, H.

    2007-01-01

    Epitaxial ZnO thin films with different orientations have been grown by laser molecular beam epitaxy on (001)- (011)-, and (111)-orientated SrTiO 3 single-crystal substrates. The growth behavior was in situ monitored by reflection high-energy electron diffraction, and the epitaxial orientation relations were reconfirmed by ex situ x-ray diffraction measurements. In the case of ZnO on SrTiO 3 (001), four orthogonal domains coexisted in the ZnO epilayer, i.e., ZnO(110) parallel SrTiO 3 (001) and ZnO[-111] parallel SrTiO 3 . For (011)- and (111)-orientated substrates, single-domain epitaxy with c axial orientation was observed, in which the in-plane relationship was ZnO[110] parallel SrTiO 3 [110] irrespective of the substrate orientations. Additionally, the crystalline quality of ZnO on SrTiO 3 (111) was better than that of ZnO on SrTiO 3 (011) because of the same symmetry between the (111) substrates and (001) films. The obtained results can be attributed to the difference of the in-plane crystallographic symmetry. Furthermore, those alignments can be explained by the interface stress between the substrates and the films

  1. Internal Spin Control, Squeezing and Decoherence in Ensembles of Alkali Atomic Spins

    Science.gov (United States)

    Norris, Leigh Morgan

    Large atomic ensembles interacting with light are one of the most promising platforms for quantum information processing. In the past decade, novel applications for these systems have emerged in quantum communication, quantum computing, and metrology. Essential to all of these applications is the controllability of the atomic ensemble, which is facilitated by a strong coupling between the atoms and light. Non-classical spin squeezed states are a crucial step in attaining greater ensemble control. The degree of entanglement present in these states, furthermore, serves as a benchmark for the strength of the atom-light interaction. Outside the broader context of quantum information processing with atomic ensembles, spin squeezed states have applications in metrology, where their quantum correlations can be harnessed to improve the precision of magnetometers and atomic clocks. This dissertation focuses upon the production of spin squeezed states in large ensembles of cold trapped alkali atoms interacting with optical fields. While most treatments of spin squeezing consider only the case in which the ensemble is composed of two level systems or qubits, we utilize the entire ground manifold of an alkali atom with hyperfine spin f greater than or equal to 1/2, a qudit. Spin squeezing requires non-classical correlations between the constituent atomic spins, which are generated through the atoms' collective coupling to the light. Either through measurement or multiple interactions with the atoms, the light mediates an entangling interaction that produces quantum correlations. Because the spin squeezing treated in this dissertation ultimately originates from the coupling between the light and atoms, conventional approaches of improving this squeezing have focused on increasing the optical density of the ensemble. The greater number of internal degrees of freedom and the controllability of the spin-f ground hyperfine manifold enable novel methods of enhancing squeezing. In

  2. Applying squeezing technique to clay-rocks: lessons learned from ten years experiments at Mont Terri

    International Nuclear Information System (INIS)

    Fernandez, A. M.; Melon, A.; Sanchez-Ledesma, D.M.; Tournassat, C.; Gaucher, E.; Astudillo, J.; Vinsot, A.

    2012-01-01

    Document available in extended abstract form only. Argillaceous formations of low permeability are considered in several countries as potential host rocks for the disposal of high level radioactive wastes (HLRW). In order to determine their suitability for waste disposal, evaluations of the hydro-geochemistry and transport mechanisms from such geologic formations to the biosphere must be undertaken. The migration of radionuclides through the geosphere will occur predominantly in the aqueous phase, and hence the pore water chemistry plays an important role in determining ion diffusion characteristics in argillaceous formations. Consequently, a great effort has been made to characterise the pore water chemistry in clay-rocks formations. In the last 10 years various techniques were developed for determining pore water composition of clay-rocks including both direct and indirect methods: 1) In situ pore water sampling (water and gas) from sealed boreholes (Pearson et al., 2003; Vinsot et al. 2008); 2) Laboratory pore water sampling from unaltered core samples by the squeezing technique at high pressures (Fernandez et al., 2009); and 3) Characterization of the water chemistry by geochemical modelling (Gaucher et al. 2009). Pore water chemistry in clay-rocks and extraction techniques were documented and reviewed in different studies (Sacchi et al., 2001). Recovering pristine pore water from low permeable and low water content systems is very difficult and sometimes impossible. Besides, uncertainties are associated to each method used for the pore water characterization. In this paper, a review about the high pressure squeezing technique applied to indurate clay-rocks was performed. For this purpose, the experimental work on Opalinus Clay at the Mont Terri Research Laboratory during the last ten years was evaluated. A complete discussion was made about different issues such as: a) why is necessary to obtain the pore water by squeezing in the context of radioactive waste

  3. Generalized squeezing rotating-wave approximation to the isotropic and anisotropic Rabi model in the ultrastrong-coupling regime

    OpenAIRE

    Zhang, Yu-Yu

    2016-01-01

    Generalized squeezing rotating-wave approximation (GSRWA) is proposed by employing both the displacement and the squeezing transformations. A solvable Hamiltonian is reformulated in the same form as the ordinary RWA ones. For a qubit coupled to oscillators experiment, a well-defined Schr\\"{o}dinger-cat-like entangled state is given by the displaced-squeezed oscillator state instead of the original displaced state. For the isotropic Rabi case, the mean photon number and the ground-state energy...

  4. Analytical solutions by squeezing to the anisotropic Rabi model in the nonperturbative deep-strong coupling regime

    OpenAIRE

    Zhang, Yu-Yu; Chen, Xiang-You

    2017-01-01

    A novel, unexplored nonperturbative deep-strong coupling (npDSC) achieved in superconducting circuits has been studied in the anisotropic Rabi model by the generalized squeezing rotating-wave approximation (GSRWA). Energy levels are evaluated analytically from the reformulated Hamiltonian and agree well with numerical ones under a wide range of coupling strength. Such improvement ascribes to deformation effects in the displaced-squeezed state presented by the squeezed momentum variance, which...

  5. A Method for Seawater Desalination via Squeezing Ionic Hydrogels.

    Science.gov (United States)

    Yu, Chi; Wang, Yanhong; Lang, Xuemei; Fan, Shuanshi

    2016-12-06

    In this study, mechanical force applied to squeeze poly(sodium acrylate-co-2-hydroxyethyl methacrylate) hydrogels that contained seawater in order to obtain fresh water. By incorporating ionic monomer sodium acrylate (SA) into hydrogels, the salt rejection was significantly enhanced from 27.62% to 64.57% (feed concentration 35.00g/L NaCl solution). As SA's concentration continuously increased, salt rejection declined due to the change in hydrogel's matrix structure. Therefore, water recovery raised as the current swelling degree increased. We also measured pore size distribution by applying mercury intrusion porosimetry on each hydrogel sample in the interest of finding out whether the sample SA5/HEMA15 owned multi pore structure, since the result could be good for the desalination performance. After 4 times reused, the hydrogel remained good desalination performance. Although compared to reverse osmosis (RO) and multistage flash distillation (MSF) & multiple effect distillation (MED) the salt rejection of this hydrogel (roughly 64%) seemed low, the hydrogels can be used for forward osmosis and reverse osmosis, as pretreatment of seawater to reduce the energy consumption for the downstream.

  6. Squeeze flow between a sphere and a textured wall

    Energy Technology Data Exchange (ETDEWEB)

    Chastel, T.; Mongruel, A., E-mail: anne.mongruel@upmc.fr [Physique et Mécanique des Milieux Hétérogènes, UMR 7636 CNRS–ESPCI, Université Pierre et Marie Curie–Université Paris-Diderot, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)

    2016-02-15

    The motion of a millimetric sphere, translating in a viscous fluid towards a wettable textured wall, is investigated experimentally. The textures consist of square arrays of cylindrical or square micro-pillars, the height, width, and spacing of which are varied, keeping the periodicity small compared to the sphere radius. An interferometric device is used to measure the sphere vertical displacement, for distances between the sphere and the base of the pillars smaller than 0.1 sphere radius, and with a resolution of 200 nm. At a given distance from the top of the pillars, the sphere velocity is found to be significantly larger than the corresponding velocity for a smooth solid wall. A squeeze flow model of two adjacent fluid layers is developed in the lubrication approximation, one fluid layer having an effective viscosity that reflects the viscous dissipation through the array of pillars. The pressure field in the gap between the sphere and the textured surface is then used to obtain the drag force on the sphere and hence its velocity. Adjustment of the model to the velocity measurements yields the effective viscosity for a given texture. Finally, a correlation between the effective viscosity and the geometry of the pillar array is proposed.

  7. Atomic squeezed states on an atom-chip

    International Nuclear Information System (INIS)

    Maussang, Kenneth

    2010-01-01

    In this thesis, we describe the construction of an experiment, allowing to produce 87 Rb Bose-Einstein condensates on an atom chip, and then split them in a double well potential. An accurate imaging system has been developed, in order to be able to measure the absolute value of the populations of the double well within a very low noise level, almost limited by the optical shot noise. We measure atom number statistics after splitting, and directly observe number squeezed states, down to -4.9 dB at low temperatures, compared to a classical gas, of independent particles. The dependence in temperature of fluctuations has been also studied. For a thermal gas, Poissonian fluctuations are given by the probability distribution of the macroscopic configurations with a given atom number difference. In the degenerate regime, the entropy effect which favors small number differences vanishes, leading to super-Poissonian fluctuations, to more than +3.8 dB close to transition temperature. At low temperatures, the interaction energy cost associated with number fluctuations exceeds the available thermal energy, leading to sub-Poissonian fluctuations. Those two behaviours have been theoretically explained, both with a simple analytical model and a numerical one. We also measured the evolution of the relative phase between the two clouds, and its collapse due to interactions, allowing us to claim that this splitter is a coherent one. (author)

  8. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian; Shao Bin; Zou Jian

    2009-01-01

    In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.

  9. Phase control of squeezed state in double electromagnetically induced transparency system with a loop-transition structure

    Science.gov (United States)

    Li, Yuan; Zhou, Yusheng; Wang, Yong; Ling, Qiang; Chen, Bing; Dou, Yan; Zhang, Wei; Gao, Weiqing; Guo, Zhiqiang; Zhang, Junxiang

    2018-03-01

    We theoretically study the squeezed probe light passing through a double electromagnetically induced transparency (DEIT) system, in which a microwave field and two coupling lights drive a loop transition. It is shown that the output squeezing can be maintained in both two transparency windows of DEIT, and it can also be manipulated by the relative phase of the three driving fields. The influence of the intensity of applied fields and the optical depth of atoms on the squeezing is also investigated. This study offers possibilities to manipulate the squeezing propagation in atomic media by the phase of electromagnetic fields.

  10. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    International Nuclear Information System (INIS)

    Jian, Zhang; Bin, Shao; Jian, Zou

    2009-01-01

    In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

  11. Squeezed light for the interferometric detection of high-frequency gravitational waves

    Science.gov (United States)

    Schnabel, R.; Harms, J.; Strain, K. A.; Danzmann, K.

    2004-03-01

    The quantum noise of the light field is a fundamental noise source in interferometric gravitational-wave detectors. Injected squeezed light is capable of reducing the quantum noise contribution to the detector noise floor to values that surpass the so-called standard quantum limit (SQL). In particular, squeezed light is useful for the detection of gravitational waves at high frequencies where interferometers are typically shot-noise limited, although the SQL might not be beaten in this case. We theoretically analyse the quantum noise of the signal-recycled laser interferometric gravitational-wave detector GEO 600 with additional input and output optics, namely frequency-dependent squeezing of the vacuum state of light entering the dark port and frequency-dependent homodyne detection. We focus on the frequency range between 1 kHz and 10 kHz, where, although signal recycled, the detector is still shot-noise limited. It is found that the GEO 600 detector with present design parameters will benefit from frequency-dependent squeezed light. Assuming a squeezing strength of -6 dB in quantum noise variance, the interferometer will become thermal noise limited up to 4 kHz without further reduction of bandwidth. At higher frequencies the linear noise spectral density of GEO 600 will still be dominated by shot noise and improved by a factor of 106dB/20dB ap 2 according to the squeezing strength assumed. The interferometer might reach a strain sensitivity of 6 × 10-23 above 1 kHz (tunable) with a bandwidth of around 350 Hz. We propose a scheme to implement the desired frequency-dependent squeezing by introducing an additional optical component into GEO 600's signal-recycling cavity.

  12. Squeezed light for the interferometric detection of high-frequency gravitational waves

    International Nuclear Information System (INIS)

    Schnabel, R; Harms, J; Strain, K A; Danzmann, K

    2004-01-01

    The quantum noise of the light field is a fundamental noise source in interferometric gravitational-wave detectors. Injected squeezed light is capable of reducing the quantum noise contribution to the detector noise floor to values that surpass the so-called standard quantum limit (SQL). In particular, squeezed light is useful for the detection of gravitational waves at high frequencies where interferometers are typically shot-noise limited, although the SQL might not be beaten in this case. We theoretically analyse the quantum noise of the signal-recycled laser interferometric gravitational-wave detector GEO 600 with additional input and output optics, namely frequency-dependent squeezing of the vacuum state of light entering the dark port and frequency-dependent homodyne detection. We focus on the frequency range between 1 kHz and 10 kHz, where, although signal recycled, the detector is still shot-noise limited. It is found that the GEO 600 detector with present design parameters will benefit from frequency-dependent squeezed light. Assuming a squeezing strength of -6 dB in quantum noise variance, the interferometer will become thermal noise limited up to 4 kHz without further reduction of bandwidth. At higher frequencies the linear noise spectral density of GEO 600 will still be dominated by shot noise and improved by a factor of 10 6dB/20dB ∼ 2 according to the squeezing strength assumed. The interferometer might reach a strain sensitivity of 6 x 10 -23 above 1 kHz (tunable) with a bandwidth of around 350 Hz. We propose a scheme to implement the desired frequency-dependent squeezing by introducing an additional optical component into GEO 600's signal-recycling cavity

  13. Slantingly cross loading sample system enables simultaneous performance of separation and mixture to detect molecular interactions on thin-layer chromatography.

    Science.gov (United States)

    Shimizu-Yumoto, Hiroko; Hayashi, Nobuyuki; Ichimura, Kazuo; Nakayama, Masayoshi

    2012-07-06

    Anthocyanins are major flower pigments that can be affected by copigments, colorless compounds that can modify anthocyanin coloration to more intense and bluer. Thin-layer chromatography (TLC) is an available technique to separate and analyze anthocyanins and copigments. To easily and comprehensively detect copigments, we added function of mixture of compounds to TLC; by slantingly cross loading samples on TLC, compounds are symmetrically developed at various angle lines from the upper origin to individual R(f) values and cross each other in an orderly fashion, where mixture is simultaneously performed with separation. Occurrence of copigments can be detected as a coloration change on the developed line of anthocyanin. Pink sweet pea (Lathyrus odoratus L.) petals were analyzed by the cross-TLC and a more intense spot and a paler spot on the anthocyanin line were detected. As each spot overlapped with an ultraviolet absorbance line, each of these ultraviolet absorption compounds was purified and identified as kaempferol 3-rhamnoside and 2-cyanoethyl-isoxazolin-5-one, respectively. Whereas kaempferol 3-rhamnoside is a flavonoid and had a general copigment effect of more intense and bluer coloration change, 2-cyanoethyl-isoxazolin-5-one is a compound whose structure is outside of conventional categories of copigments and had a novel effect to change anthocyanin coloration paler while maintaining color tone. We determined that the search for copigments should be carried out without pre-existing prediction of structures and effects. We have shown that slantingly cross loading samples system on plate-type chromatography is an effective technique for such comprehensive analysis of molecular interaction. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  14. Determination of Sudan I in paprika powder by molecularly imprinted polymers-thin layer chromatography-surface enhanced Raman spectroscopic biosensor.

    Science.gov (United States)

    Gao, Fang; Hu, Yaxi; Chen, Da; Li-Chan, Eunice C Y; Grant, Edward; Lu, Xiaonan

    2015-10-01

    Sudan I is a carcinogenic and mutagenic azo-compound that has been utilized as a common adulterant in spice and spice blends to impart a desirable red color to foods. A novel biosensor combining molecularly imprinted polymers (MIPs), thin layer chromatography (TLC) and surface enhanced Raman spectroscopy (SERS) could determine Sudan I levels in paprika powder to 1 ppm (or 2 ng/spot). Sudan I spiked paprika extracts (spiking levels: 0, 1, 5, 10, 40, 70 and 100 ppm) were prepared. Sudan I imprinted polymers were synthesized by employing the interaction between Sudan I (template) and methacrylic acid (functional monomer), followed by washing to remove Sudan I leaving the Sudan I-binding sites exposed. MIPs were used as a stationary phase for TLC and could selectively retain Sudan I at the original spot with little interference. A gold colloid SERS substrate could enhance Raman intensity for Sudan I in this MIP-TLC system. Principal component analysis plot and partial least squares regression (R(2)=0.978) models were constructed and a linear regression model (R(2)=0.983) correlated spiking levels (5, 10, 40, 70 and 100 ppm) with the peak intensities (721 cm(-1)) of Sudan I SERS spectra. Both separation (30-40s) and detection (1s or 0.1s) were extremely fast by using both commercial bench-top and custom made portable Raman spectrometers. This biosensor can be applied as a rapid, low-cost and reliable tool for screening Sudan I adulteration in foods. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Towards developing an efficient sensitive element for trinitrotoluene detection: TiO{sub 2} thin films functionalized with molecularly imprinted copolymer films

    Energy Technology Data Exchange (ETDEWEB)

    Lazau, Carmen [National Institute for Research and Development in Electrochemistry and Condensed Matter, Condensed Matter Department, 1 P. Andronescu Street, 300224 Timisoara (Romania); Iordache, Tanta-Verona [National Research and Development Institute for Chemistry and Petrochemistry INCDCP-ICECHIM, Advanced Polymer Materials and Polymer Recycling, 202 Splaiul Independentei, 060021 Bucharest (Romania); Florea, Ana-Mihaela [National Research and Development Institute for Chemistry and Petrochemistry INCDCP-ICECHIM, Advanced Polymer Materials and Polymer Recycling, 202 Splaiul Independentei, 060021 Bucharest (Romania); University Politehnica of Bucharest, The Faculty of Applied Chemistry and Materials Science, Bioresources and Polymer Science Department, 1-7 Polizu, 011061 Bucharest (Romania); Orha, Corina [National Institute for Research and Development in Electrochemistry and Condensed Matter, Condensed Matter Department, 1 P. Andronescu Street, 300224 Timisoara (Romania); Bandas, Cornelia, E-mail: cornelia.bandas@gmail.com [National Institute for Research and Development in Electrochemistry and Condensed Matter, Condensed Matter Department, 1 P. Andronescu Street, 300224 Timisoara (Romania); Radu, Anita-Laura; Sarbu, Andrei [National Research and Development Institute for Chemistry and Petrochemistry INCDCP-ICECHIM, Advanced Polymer Materials and Polymer Recycling, 202 Splaiul Independentei, 060021 Bucharest (Romania); Rotariu, Traian [Technical Military Academy, Chemistry Department, Bucharest (Romania)

    2016-10-30

    Highlights: • A new concept for creating reusable and more sensitive sensors for trinitrotoluene. • Titanium oxide thin films as transducers deposited by a new hydrothermal process. • Trinitrotoluene-molecularly imprinted receptors obtained by a two-step procedure. - Abstract: In this study, TiO{sub 2} films were successfully grown in-situ onto a FTO substrate by a hydrothermal method, using TiCl{sub 4} as Ti precursor, and further on functionalized with a 2,4,6-trinitrotoluene-molecularly imprinted polymer (TNT-MIP) film as a preliminary step in developing a trinitrotoluene (TNT) reusable sensor to overcome the international security issues. For investigating the TiO{sub 2} film thickness, crystalline structure and morphology, the films were autoclaved at 200 °C at different times. The X-ray diffraction showed that TiO{sub 2} films possessed a rutile structure, with no cracks visible by atomic force microscopy (AFM), and the films morphology observed by scanning electron microscopy (SEM) was highly dependent upon the hydrothermal treatment time. Yet, the TiO{sub 2} films with a more porous surface were more suitable for TNT-MIP film deposit. Rheology of precursor polymer film solutions, based on poly (acrylonitrile-co-acrylic acid), poly (acrylonitrile-co-methacrylic acid) or poly (acrylonitrile- co-itaconic acid), and the structure and adherence of TNT-MIP films were investigated in order to establish the correct recipe of the MIP. The removal yield of TNT from the imprinted films, the thickness, the porosity and the compatibility with the inorganic TiO{sub 2} film were adequate for the poly (acrylonitrile-co-acrylic acid) system with an acrylonitrile: acrylic acid practical ratio of 86.1:13.9 (wt./wt.). Farmore, AFM morphology corroborated with SEM results highlighted the effect of TNT imprinting in the copolymer matrix as the surface of the imprinted layer was quite different from that of the non-imprinted layer.

  16. Preparation and optical and electrical evaluation of bulk SiO2 sonogel hybrid composites and vacuum thermal evaporated thin films prepared from molecular materials derived from (Fe, Co) metallic phthalocyanines and 1,8 dihydroxiantraquinone compounds

    International Nuclear Information System (INIS)

    Sanchez Vergara, Maria Elena; Morales-Saavedra, Omar G.; Ontiveros-Barrera, Fernando G.; Torres-Zuniga, Vicente; Ortega-Martinez, Roberto; Ortiz Rebollo, Armando

    2009-01-01

    Semiconducting molecular material of PcFe(CN)L1 and PcCo(CN)L1 (L1 = 1,8 dihydroxianthraquinone), PcFe(CN)L2 and PcCo(CN)L2 (L2 = double potassium salt of 1,8 dihydroxianthraquinone) have been successfully used to prepare thin film and bulk sol-gel hybrid optical materials. These samples were developed according to the vacuum thermal evaporation technique and the catalyst-free sonogel route, respectively. Thin films samples were deposited on Corning glass substrates and crystalline silicon wafers and were characterized by infrared (FTIR), Raman and ultraviolet-visible (UV-vis) spectroscopies. IR-spectroscopy and Raman studies unambiguously confirmed that the molecular material thin films exhibit the same intra-molecular bonds, which suggests that the thermal evaporation process does not alter these bonds significantly. These results show that it is possible to deposit molecular materials of PcFe(CN)L2 and PcCo(CN)L2 on Corning glass substrates and silicon wafers. From the UV-vis studies the optical band gap (E g ) was evaluated. The effect of temperature on conductivity was also evaluated in these samples. Finally, the studied molecular systems dissolved at different concentrations in tetrahydrofuran (THF) were successfully embedded into a highly pure SiO 2 sonogel network generated via sonochemical reactions to form several solid state, optically active sol-gel hybrid glasses. By this method, homogeneous and stable hybrid monoliths suitable for optical characterization can be produced. The linear optical properties of these amorphous bulk structures were determined by the Brewster angle method and by absorption-, Raman- and photoluminescent (PL)-spectroscopies, respectively

  17. Preparation and optical and electrical evaluation of bulk SiO{sub 2} sonogel hybrid composites and vacuum thermal evaporated thin films prepared from molecular materials derived from (Fe, Co) metallic phthalocyanines and 1,8 dihydroxiantraquinone compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Vergara, Maria Elena [Coordinacion de Ingenieria Mecatronica, Facultad de Ingenieria, Universidad Anahuac Mexico Norte. Avenida Universidad Anahuac 46, Col. Lomas Anahuac, 52786 Huixquilucan, Estado de Mexico (Mexico); Morales-Saavedra, Omar G. [Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, CCADET-UNAM, A.P. 70-186, Coyoacan, 04510 Mexico, D.F. (Mexico)], E-mail: omar.morales@ccadet.unam.mx; Ontiveros-Barrera, Fernando G.; Torres-Zuniga, Vicente; Ortega-Martinez, Roberto [Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, CCADET-UNAM, A.P. 70-186, Coyoacan, 04510 Mexico, D.F. (Mexico); Ortiz Rebollo, Armando [Universidad Nacional Autonoma de Mexico, Instituto de Investigaciones en Materiales, IIM-UNAM, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico)

    2009-02-25

    Semiconducting molecular material of PcFe(CN)L1 and PcCo(CN)L1 (L1 = 1,8 dihydroxianthraquinone), PcFe(CN)L2 and PcCo(CN)L2 (L2 = double potassium salt of 1,8 dihydroxianthraquinone) have been successfully used to prepare thin film and bulk sol-gel hybrid optical materials. These samples were developed according to the vacuum thermal evaporation technique and the catalyst-free sonogel route, respectively. Thin films samples were deposited on Corning glass substrates and crystalline silicon wafers and were characterized by infrared (FTIR), Raman and ultraviolet-visible (UV-vis) spectroscopies. IR-spectroscopy and Raman studies unambiguously confirmed that the molecular material thin films exhibit the same intra-molecular bonds, which suggests that the thermal evaporation process does not alter these bonds significantly. These results show that it is possible to deposit molecular materials of PcFe(CN)L2 and PcCo(CN)L2 on Corning glass substrates and silicon wafers. From the UV-vis studies the optical band gap (E{sub g}) was evaluated. The effect of temperature on conductivity was also evaluated in these samples. Finally, the studied molecular systems dissolved at different concentrations in tetrahydrofuran (THF) were successfully embedded into a highly pure SiO{sub 2} sonogel network generated via sonochemical reactions to form several solid state, optically active sol-gel hybrid glasses. By this method, homogeneous and stable hybrid monoliths suitable for optical characterization can be produced. The linear optical properties of these amorphous bulk structures were determined by the Brewster angle method and by absorption-, Raman- and photoluminescent (PL)-spectroscopies, respectively.

  18. Structure of multiphoton quantum optics. II. Bipartite systems, physical processes, and heterodyne squeezed states

    Science.gov (United States)

    dell'Anno, Fabio; de Siena, Silvio; Illuminati, Fabrizio

    2004-03-01

    Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper [F. Dell’Anno, S. De Siena, and F. Illuminati, Phys. Rev. A 69, 033812 (2004)], we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of Hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing nondegenerate and degenerate multiphoton processes. We determine the coherent states associated with the canonical transformations, which generalize the nondegenerate two-photon squeezed states. Such heterodyne multiphoton squeezed states are defined as the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non-Gaussian, highly nonclassical, entangled states. For a quadratic nonlinearity the heterodyne multiphoton squeezed states define two-mode cubic phase states. The statistical properties of these states can be widely adjusted by tuning the heterodyne mixing angles, the phases of the nonlinear couplings, as well as the strength of the nonlinearity. For quadratic nonlinearity, we study the higher-order contributions to the susceptibility in nonlinear media and we suggest possible experimental realizations of multiphoton conversion processes generating the cubic-phase heterodyne squeezed states.

  19. Quadrature squeezing of a mechanical resonator generated by the electromechanical coupling with two coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yan [Department of Physics, Huazhong Normal University, Wuhan (China); School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Zhu, Jia-pei [Department of Physics, Honghe University, Mengzi (China); Zhao, Shao-ming; Li, Gao-xiang [Department of Physics, Huazhong Normal University, Wuhan (China)

    2015-01-01

    The quadrature squeezing of a mechanical resonator (MR) coupled with two quantum dots (QDs) through the electromechanical coupling, where the QDs are driven by a strong and two weak laser fields is investigated. By tuning the gate voltage, the electron can be trapped in a quantum pure state. Under certain conditions, the discrepancies between the transition frequency and that of two weak fields are compensated by the phonons induced by the electromechanical coupling of the MR with QDs. In this case, some dissipative processes occur resonantly. The phonons created and (or) annihilated in these dissipative processes are correlated thus leading to the quadrature squeezing of the MR. A squeezed vacuum reservoir for the MR is built up. By tuning the gate voltage to control the energy structure of the QDs, the present squeezing scheme has strong resistance against the dephasing processes of the QDs in low temperature limit. The role of the temperature of the phonon reservoir is to damage squeezing of the MR. (copyright 2014 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Structure of multiphoton quantum optics. II. Bipartite systems, physical processes, and heterodyne squeezed states

    International Nuclear Information System (INIS)

    Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2004-01-01

    Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper [F. Dell'Anno, S. De Siena, and F. Illuminati, Phys. Rev. A 69, 033812 (2004)], we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of Hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing nondegenerate and degenerate multiphoton processes. We determine the coherent states associated with the canonical transformations, which generalize the nondegenerate two-photon squeezed states. Such heterodyne multiphoton squeezed states are defined as the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non-Gaussian, highly nonclassical, entangled states. For a quadratic nonlinearity the heterodyne multiphoton squeezed states define two-mode cubic phase states. The statistical properties of these states can be widely adjusted by tuning the heterodyne mixing angles, the phases of the nonlinear couplings, as well as the strength of the nonlinearity. For quadratic nonlinearity, we study the higher-order contributions to the susceptibility in nonlinear media and we suggest possible experimental realizations of multiphoton conversion processes generating the cubic-phase heterodyne squeezed states

  1. The EUVE Mission at UCB: Squeezing More From Less

    Science.gov (United States)

    Stroozas, B. A.; Cullison, J. L.; McDonald, K. E.; Nevitt, R.; Malina, R. F.

    2000-05-01

    With 8 years on orbit, and over three years in an outsourced mode at U.C. Berkeley (UCB), NASA's Extreme Ultraviolet Explorer (EUVE) continues to be a highly mature and productive scientific mission. The EUVE satellite is extremely stable and exhibits little degradation in its original scientific capabilities, and science data return continues to be at the >99% level. The Project's very small, dedicated, innovative, and relatively cheap ( \\$1 million/year) support team at UCB continues to validate the success of NASA's outsourcing "experiment" while providing a very high science-per-dollar return on NASA's investment with no significant additional risk to the flight systems. The EUVE mission still has much more to offer in terms of important and exciting scientific discoveries as well as mission operations innovations. To highlight this belief the EUVE team at UCB continues to find creative ways to do more with less -- to squeeze the maximum out of available funds -- in NASA's "cheaper, better, faster" environment. This paper provides an overview of the EUVE mission's past, current, and potential future efforts toward automating and integrating its multi-functional data processing systems in proposal management, observation planning, mission operations and engineering, and the processing, archival, and delivery of raw telemetry and science data products. The paper will also discuss the creative allocation of the Project's few remaining personnel resources who support both core mission functions and new innovations, while at the same time minimizing overall risk and stretching the available budget. This work is funded through NASA/UCB Cooperative Agreement NCC5-138.

  2. Study of Nonlinear MHD Tribological Squeeze Film at Generalized Magnetic Reynolds Numbers Using DTM.

    Science.gov (United States)

    Rashidi, Mohammad Mehdi; Freidoonimehr, Navid; Momoniat, Ebrahim; Rostami, Behnam

    2015-01-01

    In the current article, a combination of the differential transform method (DTM) and Padé approximation method are implemented to solve a system of nonlinear differential equations modelling the flow of a Newtonian magnetic lubricant squeeze film with magnetic induction effects incorporated. Solutions for the transformed radial and tangential momentum as well as solutions for the radial and tangential induced magnetic field conservation equations are determined. The DTM-Padé combined method is observed to demonstrate excellent convergence, stability and versatility in simulating the magnetic squeeze film problem. The effects of involved parameters, i.e. squeeze Reynolds number (N1), dimensionless axial magnetic force strength parameter (N2), dimensionless tangential magnetic force strength parameter (N3), and magnetic Reynolds number (Rem) are illustrated graphically and discussed in detail. Applications of the study include automotive magneto-rheological shock absorbers, novel aircraft landing gear systems and biological prosthetics.

  3. Study of Nonlinear MHD Tribological Squeeze Film at Generalized Magnetic Reynolds Numbers Using DTM.

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Rashidi

    Full Text Available In the current article, a combination of the differential transform method (DTM and Padé approximation method are implemented to solve a system of nonlinear differential equations modelling the flow of a Newtonian magnetic lubricant squeeze film with magnetic induction effects incorporated. Solutions for the transformed radial and tangential momentum as well as solutions for the radial and tangential induced magnetic field conservation equations are determined. The DTM-Padé combined method is observed to demonstrate excellent convergence, stability and versatility in simulating the magnetic squeeze film problem. The effects of involved parameters, i.e. squeeze Reynolds number (N1, dimensionless axial magnetic force strength parameter (N2, dimensionless tangential magnetic force strength parameter (N3, and magnetic Reynolds number (Rem are illustrated graphically and discussed in detail. Applications of the study include automotive magneto-rheological shock absorbers, novel aircraft landing gear systems and biological prosthetics.

  4. Evolution of the squeezing-enhanced vacuum state in the amplitude dissipative channel

    Science.gov (United States)

    Ren, Gang; Du, Jian-ming; Zhang, Wen-hai

    2018-05-01

    We study the evolution of the squeezing-enhanced vacuum state (SEVS) in the amplitude dissipative channel by using the two-mode entangled state in the Fock space and Kraus operator. The explicit formulation of the output state is also given. It is found that the output state does not exhibit sub-Poissonian behavior for the nonnegative value of the Mandel's Q-parameters in a wide range of values of squeezing parameter and dissipation factor. It is interesting to see that second-order correlation function is independent of the dissipation factor. However, the photon-number distribution of the output quantum state shows remarkable oscillations with respect to the dissipation factor. The shape of Wigner function and the degree of squeezing show that the initial SEVS is dissipated by the amplitude dissipative channel.

  5. Squeeze behavior of magnetorheological fluids under constant volume and uniform magnetic field

    International Nuclear Information System (INIS)

    Guo, Chaoyang; Gong, Xinglong; Xuan, Shouhu; Yan, Qifan; Ruan, Xiaohui

    2013-01-01

    In this work the experimental investigation of magnetorheological fluids in squeeze mode has been carried out under constant volume with a self-developed device. The magnetorheological fluids were forced to move in all directions in a horizontal plane as the two flat surfaces came together. A pair of Helmholtz coils was used to generate a uniform magnetic field in the compression gap. The normal forces within the gap were systematically studied for different magnetic field, squeeze velocity, particle concentration, viscosity of carrier fluid and initial gap distance. Two regions of behavior were obtained from the normal force versus gap distance curve: elastic deformation and plastic flow. A power law fitting was appropriate for the relation between the normal force and the gap in the plastic flow. The index of the power law was smaller than that predicted by the continuum theory, possibly due to the squeeze strengthening effect and the sealing effect. (paper)

  6. Double stratification effects in chemically reactive squeezed Sutterby fluid flow with thermal radiation and mixed convection

    Science.gov (United States)

    Ahmad, S.; Farooq, M.; Javed, M.; Anjum, Aisha

    2018-03-01

    A current analysis is carried out to study theoretically the mixed convection characteristics in squeezing flow of Sutterby fluid in squeezed channel. The constitutive equation of Sutterby model is utilized to characterize the rheology of squeezing phenomenon. Flow characteristics are explored with dual stratification. In flowing fluid which contains heat and mass transport, the first order chemical reaction and radiative heat flux affect the transport phenomenon. The systems of non-linear governing equations have been modulating which then solved by mean of convergent approach (Homotopy Analysis Method). The graphs are reported and illustrated for emerging parameters. Through graphical explanations, drag force, rate of heat and mass transport are conversed for different pertinent parameters. It is found that heat and mass transport rate decays with dominant double stratified parameters and chemical reaction parameter. The present two-dimensional examination is applicable in some of the engineering processes and industrial fluid mechanics.

  7. Squeezed bispectrum in the δ N formalism: local observer effect in field space

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Yuichiro [Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Vennin, Vincent, E-mail: yuichiro.tada@ipmu.jp, E-mail: vincent.vennin@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

    2017-02-01

    The prospects of future galaxy surveys for non-Gaussianity measurements call for the development of robust techniques for computing the bispectrum of primordial cosmological perturbations. In this paper, we propose a novel approach to the calculation of the squeezed bispectrum in multiple-field inflation. With use of the δ N formalism, our framework sheds new light on the recently pointed out difference between the squeezed bispectrum for global observers and that for local observers, while allowing one to calculate both. For local observers in particular, the squeezed bispectrum is found to vanish in single-field inflation. Furthermore, our framework allows one to go beyond the near-equilateral ('small hierarchy') limit, and to automatically include intrinsic non-Gaussianities that do not need to be calculated separately. The explicit computational programme of our method is given and illustrated with a few examples.

  8. Low-noise, transformer-coupled resonant photodetector for squeezed state generation.

    Science.gov (United States)

    Chen, Chaoyong; Shi, Shaoping; Zheng, Yaohui

    2017-10-01

    In an actual setup of squeezed state generation, the stability of a squeezing factor is mainly limited by the performance of the servo-control system, which is mainly influenced by the shot noise and gain of a photodetector. We present a unique transformer-coupled LC resonant amplifier as a photodetector circuit to reduce the electronic noise and increase the gain of the photodetector. As a result, we obtain a low-noise, high gain photodetector with the gain of more than 1.8×10 5 V/A, and the input current noise of less than 4.7 pA/Hz. By adjusting the parameters of the transformer, the quality factor Q of the resonant circuit is close to 100 in the frequency range of more than 100 MHz, which meets the requirement for weak power detection in the application of squeezed state generation.

  9. The Effect of Spin Squeezing on the Entanglement Entropy of Kicked Tops

    Directory of Open Access Journals (Sweden)

    Ernest Teng Siang Ong

    2016-04-01

    Full Text Available In this paper, we investigate the effects of spin squeezing on two-coupled quantum kicked tops, which have been previously shown to exhibit a quantum signature of chaos in terms of entanglement dynamics. Our results show that initial spin squeezing can lead to an enhancement in both the entanglement rate and the asymptotic entanglement for kicked tops when the initial state resides in the regular islands within a mixed classical phase space. On the other hand, we found a reduction in these two quantities if we were to choose the initial state deep inside the chaotic sea. More importantly, we have uncovered that an application of periodic spin squeezing can yield the maximum attainable entanglement entropy, albeit this is achieved at a reduced entanglement rate.

  10. Effect of oscillation mode on the free-molecule squeeze-film air damping

    KAUST Repository

    Gang Hong,

    2010-01-01

    A 3D Monte Carlo (MC) simulation approach is developed and employed to study the effect of the oscillation mode on the squeeze-film air damping in the free-molecule regime. By tracking individual gas molecule\\'s motion and its interaction with the resonator, the MC approach is by far the most accurate modeling approach for the modeling of squeeze-film damping in the free-molecule regime. The accuracy of this approach is demonstrated on several cases in which either analytical solutions or experimental measurements are available. It has been found that unlike the case when resonators oscillate in an unbounded domain, squeeze film damping is very sensitive to the mode shape, which implies that some of the existing modeling approaches based on rigid-resonator assumption may not be accurate when applied to model resonators oscillating at their deformed shape. ©2010 IEEE.

  11. On the evolution of InAs thin films grown by molecular beam epitaxy on the GaAs(001) surface

    International Nuclear Information System (INIS)

    Grabowski, Jan

    2010-01-01

    Semiconductor nanostructures are currently of high interest for a wide variety of electronic and optoelectronic applications. A large number of devices, in particular for the optical data transmission in the long-wavelength range, essential in modern communication, are based on InAs/GaAs quantum dot (QD) structures. Though the properties of the InAs/GaAs QDs have been extensively studied, only little is known about the formation and structure of the wetting layer (WL) yet. In the present work, the pathway of the InAs WL evolution is studied in detail. For this purpose, InAs thin films in the range of one monolayer (ML) are deposited on the GaAs(001) surface by molecular beam epitaxy (MBE) and studied by reflection high energy electron diffraction (RHEED) and in particular by scanning tunneling microscopy (STM). The InAs thin films are grown in both typical growth regimes, on the GaAs-c(4 x 4) and the GaAs-β2(2 x 4) reconstructed surface, in a variety of thicknesses starting from submonolayers with 0.09 ML of InAs up to 1.65 ML of InAs exceeding the critical thickness for QD growth. In principle, three growth stages are found. At low InAs coverages, the indium adsorbs in agglomerations of typically eight In atoms at energetically preferable surface sites. In the STM images, the signatures of these In agglomerations appear with a clear bright contrast. A structural model for the initial formation of these signatures is presented, and its electronic and strain related properties are discussed. At an InAs coverage of about 0.67ML the initial surface transforms into a (4 x 3) reconstructed In 2/3 Ga 1/3 As ML and the detailed structure and strain properties of this surface are unraveled. On top of the InGaAs ML further deposited InAs forms a second layer, characterized by a typical zig-zag alignment of (2 x 4) reconstructed unit cells, with an alternating α2/α2-m configuration. In contrast to the previous surface reconstructions, where structural strain is

  12. On the evolution of InAs thin films grown by molecular beam epitaxy on the GaAs(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, Jan

    2010-12-14

    Semiconductor nanostructures are currently of high interest for a wide variety of electronic and optoelectronic applications. A large number of devices, in particular for the optical data transmission in the long-wavelength range, essential in modern communication, are based on InAs/GaAs quantum dot (QD) structures. Though the properties of the InAs/GaAs QDs have been extensively studied, only little is known about the formation and structure of the wetting layer (WL) yet. In the present work, the pathway of the InAs WL evolution is studied in detail. For this purpose, InAs thin films in the range of one monolayer (ML) are deposited on the GaAs(001) surface by molecular beam epitaxy (MBE) and studied by reflection high energy electron diffraction (RHEED) and in particular by scanning tunneling microscopy (STM). The InAs thin films are grown in both typical growth regimes, on the GaAs-c(4 x 4) and the GaAs-{beta}2(2 x 4) reconstructed surface, in a variety of thicknesses starting from submonolayers with 0.09 ML of InAs up to 1.65 ML of InAs exceeding the critical thickness for QD growth. In principle, three growth stages are found. At low InAs coverages, the indium adsorbs in agglomerations of typically eight In atoms at energetically preferable surface sites. In the STM images, the signatures of these In agglomerations appear with a clear bright contrast. A structural model for the initial formation of these signatures is presented, and its electronic and strain related properties are discussed. At an InAs coverage of about 0.67ML the initial surface transforms into a (4 x 3) reconstructed In{sub 2/3}Ga{sub 1/3}As ML and the detailed structure and strain properties of this surface are unraveled. On top of the InGaAs ML further deposited InAs forms a second layer, characterized by a typical zig-zag alignment of (2 x 4) reconstructed unit cells, with an alternating {alpha}2/{alpha}2-m configuration. In contrast to the previous surface reconstructions, where

  13. Buffer-layer enhanced crystal growth of BaB6 (1 0 0) thin films on MgO (1 0 0) substrates by laser molecular beam epitaxy

    International Nuclear Information System (INIS)

    Kato, Yushi; Yamauchi, Ryosuke; Arai, Hideki; Tan, Geng; Tsuchimine, Nobuo; Kobayashi, Susumu; Saeki, Kazuhiko; Takezawa, Nobutaka; Mitsuhashi, Masahiko; Kaneko, Satoru; Yoshimoto, Mamoru

    2012-01-01

    Crystalline BaB 6 (1 0 0) thin films can be fabricated on MgO (1 0 0) substrates by inserting a 2-3 nm-thick epitaxial SrB 6 (1 0 0) buffer layer by pulsed laser deposition (PLD) in ultra-high vacuum (i.e., laser molecular beam epitaxy). Reflection high-energy electron diffraction and X-ray diffraction measurements indicated the heteroepitaxial structure of BaB 6 (1 0 0)/SrB 6 (1 0 0)/MgO (1 0 0) with the single domain of the epitaxial relationship. Conversely, BaB 6 thin films without the buffer layer were not epitaxial instead they developed as polycrystalline films with a random in-plane configuration and some impurity phases. As a result, the buffer layer is considered to greatly affect the initial growth of epitaxial BaB 6 thin films; therefore, in this study, buffering effects have been discussed. From the conventional four-probe measurement, it was observed that BaB 6 epitaxial thin films exhibit n-type semiconducting behavior with a resistivity of 2.90 × 10 -1 Ω cm at room temperature.

  14. Entanglement between atomic thermal states and coherent or squeezed photons in a damping cavity

    Science.gov (United States)

    Yadollahi, F.; Safaiee, R.; Golshan, M. M.

    2018-02-01

    In the present study, the standard Jaynes-Cummings model, in a lossy cavity, is employed to characterize the entanglement between atoms and photons when the former is initially in a thermal state (mixed ensemble) while the latter is described by either coherent or squeezed distributions. The whole system is thus assumed to be in equilibrium with a heat reservoir at a finite temperature T, and the measure of negativity is used to determine the time evolution of atom-photon entanglement. To this end, the master equation for the density matrix, in the secular approximation, is solved and a partial transposition of the result is made. The degree of atom-photon entanglement is then numerically computed, through the negativity, as a function of time and temperature. To justify the behavior of atom-photon entanglement, moreover, we employ the so obtained total density matrix to compute and analyze the time evolution of the initial photonic coherent or squeezed probability distributions and the squeezing parameters. On more practical points, our results demonstrate that as the initial photon mean number increases, the atom-photon entanglement decays at a faster pace for the coherent distribution compared to the squeezed one. Moreover, it is shown that the degree of atom-photon entanglement is much higher and more stable for the squeezed distribution than that for the coherent one. Consequently, we conclude that the time intervals during which the atom-photon entanglement is distillable is longer for the squeezed distribution. It is also illustrated that as the temperature increases the rate of approaching separability is faster for the coherent initial distribution. The novel point of the present report is the calculation of dynamical density matrix (containing all physical information) for the combined system of atom-photon in a lossy cavity, as well as the corresponding negativity, at a finite temperature.

  15. Entropy squeezing of the field interacting with a nearly degenerate V-type three-level atom

    Institute of Scientific and Technical Information of China (English)

    Zhou Qing-Chun; Zhu Shi-Ning

    2005-01-01

    The position- and momentum-entopic squeezing properties of the optical field in the system of a nearly degenerate three-level atom interacting with a single-mode field are investigated. Calculation results indicate that when the field is initially in the vacuum state, it may lead to squeezing of the position entropy or the momentum entropy of the field if the atom is prepared properly. The effects of initial atomic state and the splitting of the excited levels of the atom on field entropies are discussed in this case. When the initial field is in a coherent state, we find that position-entropy squeezing of the field is present even if the atom is prepared in the ground state. By comparing the variance squeezing and entropy squeezing of the field we confirm that entropy is more sensitive than variance in measuring quantum fluctuations.

  16. Generalized squeezing rotating-wave approximation to the isotropic and anisotropic Rabi model in the ultrastrong-coupling regime

    Science.gov (United States)

    Zhang, Yu-Yu

    2016-12-01

    Generalized squeezing rotating-wave approximation (GSRWA) is proposed by employing both the displacement and the squeezing transformations. A solvable Hamiltonian is reformulated in the same form as the ordinary RWA ones. For a qubit coupled to oscillators experiment, a well-defined Schrödinger-cat-like entangled state is given by the displaced-squeezed oscillator state instead of the original displaced state. For the isotropic Rabi case, the mean photon number and the ground-state energy are expressed analytically with additional squeezing terms, exhibiting a substantial improvement of the GSRWA. And the ground-state energy in the anisotropic Rabi model confirms the effectiveness of the GSRWA. Due to the squeezing effect, the GSRWA improves the previous methods only with the displacement transformation in a wide range of coupling strengths even for large atom frequency.

  17. The precision and torque production of common hip adductor squeeze tests used in elite football

    DEFF Research Database (Denmark)

    Light, N; Thorborg, K

    2016-01-01

    OBJECTIVES: Decreased hip adductor strength is a known risk factor for groin injury in footballers, with clinicians testing adductor strength in various positions and using different protocols. Understanding how reliable and how much torque different adductor squeeze tests produce will facilitate...... choosing the most appropriate method for future testing. In this study, the reliability and torque production of three common adductor squeeze tests were investigated. DESIGN: Test-retest reliability and cross-sectional comparison. METHODS: Twenty elite level footballers (16-33 years) without previous...

  18. SQUEEZING EFFECT OF RAIL LOADED BY SEMI-SLEEPERS HAVING L-SHAPED CROSS-SECTION

    Directory of Open Access Journals (Sweden)

    V. N. Sukhodoev

    2015-01-01

    Full Text Available The paper considers a problem on introduction of a conception and regularities of “squeezing effect of a rail loaded non centrally by semi-sleepers having L-shaped cross-section” exemplified by belt-type tramway. Its advantages are ensured by doubled non centrally loaded foundations these are semi-sleepers. Semi-sleeper of L-shape cross-section is a lever of L-shape form, transforming a vertical load into horizontal ones and foundation squeezing. Properties of two semi-sleepers being doubled, orientated to each other and non centrally loaded have been used in order to create a positive effect. A horizontal force creates squeezing and it is revealed as a component of a vertical load during displacements which functionally depend on foundation squeezing. These dependences demonstrate that strength and deformation properties of earth foundation of vertical direction are used for creation of horizontal properties of sleeper vertical shoulder.The paper studies mechanics pertaining to a squeezing effect of a rail loaded by semi-sleepers having L-shaped cross-section. It has been established that the rail squeezing effect results from squeezing process executed in two mutually perpendicular directions (reduction of cross-sectional area by load of a rail wheel with spacers if they are set inside of a sleeper-mechanism on an elastic foundation.Methodology for calculation of parameters on the rail reduction effect is considered as a tool for handling of applied problems on belt-type tramways. Results of the proposed rail reduction effect in problem statement for elastic conditions, with unchanged cross-sectional dimension of a rail line and introduction of correction ratio coefficients due to new initial load data have recommended for practical application as reliable values.The paper has revealed a proportional dependence of the rail reduction effect according to strength on the resultant value of reaction pressure, eccentricity difference of the

  19. Quantum noise on a point charge from electromagnetic squeezed vacuum fluctuations

    International Nuclear Information System (INIS)

    Wu, Tai-Hung; Hsiang, Jen-Tsung; Lee, Da-Shin

    2010-01-01

    The effect of quantum noises on a point charge from electromagnetic squeezed vacuum fluctuations is studied. Here a novel reduction phenomenon in velocity dispersion is found in the situation when the particle barely moves. It shows that the velocity dispersion of the charge can be reduced below the value solely given by the normal vacuum states of the electromagnetic fields by using an appropriate choice of the squeeze parameters. This may be viewed as a transient phenomenon. Optimally utilizing this reduction scheme for gravitational wave detection is possible, but challenging.

  20. Quantum noise on a point charge from electromagnetic squeezed vacuum fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tai-Hung; Hsiang, Jen-Tsung; Lee, Da-Shin [National Dong-Hwa University, Hua-lien, Taiwan (China)

    2010-09-15

    The effect of quantum noises on a point charge from electromagnetic squeezed vacuum fluctuations is studied. Here a novel reduction phenomenon in velocity dispersion is found in the situation when the particle barely moves. It shows that the velocity dispersion of the charge can be reduced below the value solely given by the normal vacuum states of the electromagnetic fields by using an appropriate choice of the squeeze parameters. This may be viewed as a transient phenomenon. Optimally utilizing this reduction scheme for gravitational wave detection is possible, but challenging.

  1. Displaced squeezed number states: Position space representation, inner product, and some applications

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Jørgensen, Thomas Godsk; Dahl, Jens Peder

    1996-01-01

    For some applications the overall phase of a quantum state is crucial. For the so-called displaced squeezed number state (DSN), which is a generalization of the well-known squeezed coherent state, we obtain the position space representation with the correct overall phase, from the dynamics...... in a harmonic potential. The importance of the overall phase is demonstrated in the context of characteristic or moment generating functions. For two special cases the characteristic function is shown to be computable from the inner product of two different DSNs....

  2. Elastomer damper performance - A comparison with a squeeze film for a supercritical power transmission shaft

    Science.gov (United States)

    Zorzi, E. S.; Burgess, G.; Cunningham, R.

    1980-01-01

    This paper describes the design and testing of an elastomer damper on a super-critical power transmission shaft. The elastomers were designed to provide acceptable operation through the fourth bending mode and to control synchronous as well as nonsynchronous vibration throughout the operating range. The design of the elastomer was such that it could be incorporated into the system as a replacement for a squeeze-film damper without a reassembly, which could have altered the imbalance of the shaft. This provided a direct comparison of the elastomer and squeeze-film dampers without having to assess the effect of shaft imbalance changes.

  3. Coastal and Estuarine Mangrove Squeeze in the Mekong and Saigon Delta

    Science.gov (United States)

    Stive, M.

    2016-02-01

    Both in the Mekong and Saigon deltas coastal squeeze is a frequent and pregnant problem, which leads to amazingly alarmous coastal and estuarine erosion rates. From the landside the squeeze is due to encroaching dike relocations and agri- and aquacultures, from the sea side it is due to decreasing sediment sources and relative sea level rise. These multiple pressures at some locations, certainly away from the sediment sources (like Ca Mau) leads to unprecedentent erosion rates. Managed retreat may be a longer term solution, but this will require a new way of thinking. Sandy and silt nourishment strategies may be an innovative alternative, but will require underbuilding scientific and practical research.

  4. Searching for squeezed particle-antiparticle correlations in high-energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Padula, Sandra S.; Socolowski, O. Jr.

    2010-01-01

    Squeezed correlations of particle-antiparticle pairs were predicted to exist if the hadron masses were modified in the hot and dense medium formed in high-energy heavy-ion collisions. Although well-established theoretically, they have not yet been observed experimentally. We suggest here a clear method to search for such a signal by analyzing the squeezed correlation functions in terms of measurable quantities. We illustrate this suggestion for simulated φφ pairs at the Relativistic Heavy Ion Collider (RHIC) energies.

  5. Effect of magnon-phonon interactions on magnon squeezed states in ferromagnets

    Science.gov (United States)

    Mikhail, I. F. I.; Ismail, I. M. M.; Ameen, M.

    2018-02-01

    The squeezed states of dressed magnons in ferromagnets have been investigated. No effective Debye cutoff frequency has been assumed unlike what has been done hitherto. Instead, the results have been expressed throughout in terms of the reduced temperature. The effect of dressed magnon-phonon interactions on the formulation of these states has been studied. It has been shown that the magnon-phonon interactions play a significant role in determining the squeeze factor and the variation of the dressed magnon effective mass with temperature.

  6. Superposition of number and squeezed states of the quantized light field

    International Nuclear Information System (INIS)

    De Brito, A.L.; Marques, G.A.; Baseia, B.; Dias, H.

    1998-01-01

    A recent paper in the literature (Mod. Phys. Lett. B, 9 (1995) 1673) introduced the Intermediate Number Squeezed State (INSS) of the quantized radiation field interpolating between the number state (n) and the squeezed-coherent state (z, α), exhibiting various nonclassical properties. Here, it's introduced an alternative state, interpolating between those limiting states and show that nonclassical effects in this new intermediate state can be greater than those exhibited by the INSS, depending on the values of the interpolating parameters. Although constituting an application of a general approach (Nuovo Cimento D, 18 (1996) 425), it concludes another case in the literature (Phys. Scr., 55 (1997) 179) as a particularisation of this

  7. Squeezed-light generation in a nonlinear planar waveguide with a periodic corrugation

    International Nuclear Information System (INIS)

    Perina, Jan Jr.; Haderka, Ondrej; Sibilia, Concita; Bertolotti, Mario; Scalora, Michael

    2007-01-01

    Two-mode nonlinear interaction (second-harmonic and second-subharmonic generation) in a planar waveguide with a small periodic corrugation at the surface is studied. Scattering of the interacting fields on the corrugation leads to constructive interference that enhances the nonlinear process provided that all the interactions are phase matched. Conditions for the overall phase matching are found. Compared with a perfectly quasi-phase-matched waveguide, better values of squeezing as well as higher intensities are reached under these conditions. Procedure for finding optimum values of parameters for squeezed-light generation is described

  8. Managing the spatial properties and photon correlations in squeezed non-classical twisted light

    Science.gov (United States)

    Zakharov, R. V.; Tikhonova, O. V.

    2018-05-01

    Spatial photon correlations and mode content of the squeezed vacuum light generated in a system of two separated nonlinear crystals is investigated. The contribution of both the polar and azimuthal modes with non-zero orbital angular momentum is analyzed. The control and engineering of the spatial properties and degree of entanglement of the non-classical squeezed light by changing the distance between crystals and pump parameters is demonstrated. Methods for amplification of certain spatial modes and managing the output mode content and intensity profile of quantum twisted light are suggested.

  9. Influence of the bismuth deficit on the structural and electric properties of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} thin films synthesized by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Alami, H.El.; Rannou, I.; Deville Cavellin, C

    2004-07-15

    BiSrCaCuO thin films were grown on (1 0 0) SrTiO3 substrates by molecular beam epitaxy (MBE) with variation of the Bi deposition time. A new 2x212 family with x varied between 1 and 0 was grown. The X-ray study, the Rutherford back scattering (RBS), reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM) were used to characterize the films. It was shown that the growth method used leads to intergrowth nanostructures. The transport measurements of BiSrCaCuO thin films were performed. The results analysed using the theory of percolation show a 2D character of conductivity in the films studied.

  10. High-quality AlGaN/GaN grown on sapphire by gas-source molecular beam epitaxy using a thin low-temperature AlN layer

    Energy Technology Data Exchange (ETDEWEB)

    Jurkovic, M.J.; Li, L.K.; Turk, B.; Wang, W.I.; Syed, S.; Simonian, D.; Stormer, H.L.

    2000-07-01

    Growth of high-quality AlGaN/GaN heterostructures on sapphire by ammonia gas-source molecular beam epitaxy is reported. Incorporation of a thin AlN layer grown at low temperature within the GaN buffer is shown to result in enhanced electrical and structural characteristics for subsequently grown heterostructures. AlGaN/GaN structures exhibiting reduced background doping and enhanced Hall mobilities (2100, 10310 and 12200 cm{sup 2}/Vs with carrier sheet densities of 6.1 x 10{sup 12} cm{sup {minus}2}, and 5.8 x 10{sup 12} cm{sup {minus}2} at 300 K, 77 K, and 0.3 K, respectively) correlate with dislocation filtering in the thin AlN layer. Magnetotransport measurements at 0.3 K reveal well-resolved Shubnikov-de Haas oscillations starting at 3 T.

  11. Using squeeze-film effect to reduce surface friction in electrostatic actuators

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Yamamoto, Akio; Zhang, Zhe

    2015-01-01

    This paper presents a method of reducing load friction in two degrees-of-freedom (2-DOF) transparent electrostatic induction actuator by using vibration-induced squeeze film effect. An experimental set-up was built to prove the concept. An overall 70% reduction in required driving voltage...

  12. A macromodel for squeeze-film air damping in the free-molecule regime

    KAUST Repository

    Hong, Gang; Ye, Wenjing

    2010-01-01

    A three-dimensional Monte Carlo(MC) simulation approach is developed for the accurate prediction of the squeeze-film air damping on microresonators in the free-molecule gas regime. Based on the MC simulations and the analytical traveling

  13. Squeezing resulting from a fourth-order interaction in a degenerate parametric amplifier with absorption losses

    Science.gov (United States)

    Garca Fernández, P.; Colet, P.; Toral, R.; San Miguel, M.; Bermejo, F. J.

    1991-05-01

    The squeezing properties of a model of a degenerate parametric amplifier with absorption losses and an added fourth-order nonlinearity have been analyzed. The approach used consists of obtaining the Langevin equation for the optical field from the Heisenberg equation provided that a linearization procedure is valid. The steady states of the deterministic equations have been obtained and their local stability has been analyzed. The stationary covariance matrix has been calculated below and above threshold. Below threshold, a squeezed vacuum state is obtained and the nonlinear effects in the fluctuations have been taken into account by a Gaussian decoupling. In the case above threshold, a phase-squeezed coherent state is obtained and numerical simulations allowed to compute the time interval, depending on the loss parameter, on which the system jumps from one stable state to the other. Finally, the variances numerically determined have been compared with those obtained from the linearized theory and the limits of validity of the linear theory have been analyzed. It has become clear that the nonlinear contribution may perhaps be profitably used for the construction of above-threshold squeezing devices.

  14. On the quantum information entropies and squeezing associated with the eigenstates of the isotonic oscillator

    International Nuclear Information System (INIS)

    Ghasemi, A; Hooshmandasl, M R; Tavassoly, M K

    2011-01-01

    In this paper we calculate the position and momentum space information entropies for the quantum states associated with a particular physical system, i.e. the isotonic oscillator Hamiltonian. We present our results for its ground states, as well as for its excited states. We observe that the lower bound of the sum of the position and momentum entropies expressed by the Beckner, Bialynicki-Birula and Mycielski (BBM) inequality is satisfied. Moreover, there exist eigenstates that exhibit squeezing in the position information entropy. In fact, entropy squeezing, which occurs in position, will be compensated for by an increase in momentum entropy, such that the BBM inequality is guaranteed. To complete our study we investigate the amplitude squeezing in x and p-quadratures corresponding to the eigenstates of the isotonic oscillator and show that amplitude squeezing, again in x, will be revealed as expected, while the Heisenberg uncertainty relationship is also satisfied. Finally, our numerical calculations of the entropy densities will be presented graphically.

  15. Ultrafast optical generation of squeezed magnon states and long lifetime coherent LO phonons

    Science.gov (United States)

    Zhao, Jimin

    2005-12-01

    Ultrafast optical pulses have been used to generate, probe, and control low-energy elementary excitations in crystals. In particular, we report the first experimental demonstration of the generation of quantum squeezed states of magnons (collective spin-wave excitations) in a magnetic material, and new progress in experimental investigation of anharmonic interactions in a semiconductor. The mechanism for the magnon squeezing is two-magnon impulsive stimulated Raman scattering (ISRS). Femtosecond laser pulses have been used to coherently correlate degenerate counter-propagating magnons in the antiferromagnetic insulator MnF2. In the squeezed state, fluctuations of the magnetization of a crystallographic unit cell vary periodically in time and are reduced below that of the ground-state quantum noise. Similar experiments were also performed in another antiferromagnetic insulator, FeF2, for which the squeezing effect is one order of magnitude larger. We have also investigated the anharmonic interaction of the low-frequency E2 phonon in ZnO through ISRS. Temperature dependence of the linewidth and frequency indicates that the two-phonon up-conversion process is the dominant decay channel and isotopic disorder may be the main limit on the lifetime at low temperature. We have observed the longest lifetime of an optical phonon mode in a solid (211 ps at 5 K). And we have found that pump-probe experiments, compared with spontaneous Raman spectroscopy, have extremely high accuracy in determining the frequency of a low-lying excitation.

  16. 18 CFR 2.17 - Price discrimination and anticompetitive effect (price squeeze issue).

    Science.gov (United States)

    2010-04-01

    ... INTERPRETATIONS Statements of General Policy and Interpretations Under the Federal Power Act § 2.17 Price... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Price discrimination and anticompetitive effect (price squeeze issue). 2.17 Section 2.17 Conservation of Power and Water...

  17. Spin Squeezing and Entanglement with Room Temperature Atoms for Quantum Sensing and Communication

    DEFF Research Database (Denmark)

    Shen, Heng

    magnetometer at room temperature is reported. Furthermore, using spin-squeezing of atomic ensemble, the sensitivity of magnetometer is improved. Deterministic continuous variable teleportation between two distant atomic ensembles is demonstrated. The fidelity of teleportating dynamically changing sequence...... of spin states surpasses a classical benchmark, demonstrating the true quantum teleportation....

  18. Double stratification effects in chemically reactive squeezed Sutterby fluid flow with thermal radiation and mixed convection

    Directory of Open Access Journals (Sweden)

    S. Ahmad

    2018-03-01

    Full Text Available A current analysis is carried out to study theoretically the mixed convection characteristics in squeezing flow of Sutterby fluid in squeezed channel. The constitutive equation of Sutterby model is utilized to characterize the rheology of squeezing phenomenon. Flow characteristics are explored with dual stratification. In flowing fluid which contains heat and mass transport, the first order chemical reaction and radiative heat flux affect the transport phenomenon. The systems of non-linear governing equations have been modulating which then solved by mean of convergent approach (Homotopy Analysis Method. The graphs are reported and illustrated for emerging parameters. Through graphical explanations, drag force, rate of heat and mass transport are conversed for different pertinent parameters. It is found that heat and mass transport rate decays with dominant double stratified parameters and chemical reaction parameter. The present two-dimensional examination is applicable in some of the engineering processes and industrial fluid mechanics. Keywords: Squeezing flow, Sutterby fluid model, Mixed convection, Double stratification, Thermal radiation, Chemical reaction

  19. Combined Ramp and Squeeze to 6.5 TeV in the LHC

    CERN Document Server

    Solfaroli Camillocci, Matteo; Tomás, Rogelio; Wenninger, Jorg

    2016-01-01

    The cycle of the LHC is composed of an energy ramp followed by a betatron squeeze, needed to reduce the beta- star value in the interaction points. Since Run 1, studies have been carried out to investigate the feasibility of combining the two operations, thus considerably reducing the duration of the operational cycle. In Run 2, the LHC is operating at the energy of 6.5 TeV that requires a much longer cycle than that of Run 1. Therefore, the performance gains from a Combined Ramp and Squeeze (CRS) is more interesting. Merging the energy ramp and the betatron squeeze could result in a gain of several minutes for each LHC cycle. With increasing maturity of LHC operation, it is now possible to envisage more complex beam manipulations; this paper describes the first machine experiment with beam, aiming at validating the combination of ramp and squeeze, which was performed in 2015, during a machine development phase. The operation experience with the LHC run at 2.51 TeV, when CRS down to 4 meters was deployed and ...

  20. Squeezing and entanglement in doubly resonant, type II, second-harmonic generation

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Buchhave, Preben

    2003-01-01

    We investigate, theoretically, the generation of bright and vacuum-squeezed light as well as entanglement in intracavity, type II, phase-matched second-harmonic generation. The cavity in which the crystal is embedded is resonant at the fundamental frequency but not at the second-harmonic frequenc...

  1. Semiclassical approach to squeezing-like transformations in quantum systems with higher symmetries

    International Nuclear Information System (INIS)

    Klimov, Andrei B; Dinani, Hossein Tavakoli; De Guise, Hubert

    2013-01-01

    We provide a coarse but intuitive classification of squeezing in quantum systems with SU(n) symmetries. This classification is based on the non-equivalent paths (classical trajectories) in the corresponding phase-space. The example of SU(3) is studied in details. (paper)

  2. A magneto-rheological fluid mount featuring squeeze mode: analysis and testing

    International Nuclear Information System (INIS)

    Chen, Peng; Bai, Xian-Xu; Qian, Li-Jun; Choi, Seung-Bok

    2016-01-01

    This paper presents a mathematical model for a new semi-active vehicle engine mount utilizing magneto-rheological (MR) fluids in squeeze mode (MR mount in short) and validates the model by comparing analysis results with experimental tests. The proposed MR mount is mainly comprised of a frame for installation, a main rubber, a squeeze plate and a bobbin for coil winding. When the magnetic fields on, MR effect occurs in the upper gap between the squeeze plate and the bobbin, and the dynamic stiffness can be controlled by tuning the applied currents. Employing Bingham model and flow properties between parallel plates of MR fluids, a mathematical model for the squeeze type of MR mount is formulated with consideration of the fluid inertia, MR effect and hysteresis property. The field-dependent dynamic stiffness of the MR mount is then analyzed using the established mathematical model. Subsequently, in order to validate the mathematical model, an appropriate size of MR mount is fabricated and tested. The field-dependent force and dynamic stiffness of the proposed MR mount are evaluated and compared between the model and experimental tests in both time and frequency domains to verify the model efficiency. In addition, it is shown that both the damping property and the stiffness property of the proposed MR mount can be simultaneously controlled. (paper)

  3. Spin squeezing and Schrödinger cat generation in atomic samples with Rydberg blockade

    DEFF Research Database (Denmark)

    Opatrný, Tomáš; Mølmer, Klaus

    2012-01-01

    A scheme is proposed to prepare squeezed states and Schrödinger-cat-like states of the collective spin degrees of freedom associated with a pair of ground states in an atomic ensemble. The scheme uses an effective Jaynes-Cummings interaction which can be provided by excitation of the atoms...

  4. Exploring Imperfect Squeezing Flow Measurements in a Teflon Geometry for Semisolid Foods

    NARCIS (Netherlands)

    Terpstra, M.E.J.; Janssen, A.M.; Linden, van der E.

    2007-01-01

    The method of imperfect lubricated squeezing flow in a Teflon¿ geometry has been explored for the characterization of elongational behavior of custard and mayonnaise. Two Newtonian products, one of low (0.07 Pas) and one of high (18 Pas) shear viscosity, were used as references. Measurements of

  5. Modelling of magnetorheological squeeze film dampers for vibration suppression of rigid rotors

    Czech Academy of Sciences Publication Activity Database

    Zapoměl, Jaroslav; Ferfecki, Petr; Kozánek, Jan

    2017-01-01

    Roč. 127, Jul SI (2017), s. 191-197 ISSN 0020-7403 R&D Projects: GA ČR GA15-06621S Institutional support: RVO:61388998 Keywords : squeeze film damper * magnetorheological fluid * bilinear material * rigid rotor * frequency response Subject RIV: JR - Other Machinery OBOR OECD: Mechanical engineering Impact factor: 2.884, year: 2016

  6. Squeeze flow of Bingham plastic with stick-slip at the wall

    Science.gov (United States)

    Muravleva, Larisa

    2018-03-01

    We solve numerically the axisymmetric squeeze flow of a viscoplastic Bingham medium with slip yield boundary condition at the wall. Using the original Bingham model we compute the shape of the yield surface, the velocity, and stress fields employing the augmented Lagrangian methods. We confirm numerically the recently obtained asymptotic solution.

  7. Effect of oscillation mode on the free-molecule squeeze-film air damping

    KAUST Repository

    Gang Hong,; Wenjing Ye,

    2010-01-01

    A 3D Monte Carlo (MC) simulation approach is developed and employed to study the effect of the oscillation mode on the squeeze-film air damping in the free-molecule regime. By tracking individual gas molecule's motion and its interaction

  8. Some optical and electron microscope comparative studies of excimer laser-assisted and nonassisted molecular-beam epitaxically grown thin GaAs films on Si

    Science.gov (United States)

    Lao, Pudong; Tang, Wade C.; Rajkumar, K. C.; Guha, S.; Madhukar, A.; Liu, J. K.; Grunthaner, F. J.

    1990-01-01

    The quality of GaAs thin films grown via MBE under pulsed excimer laser irradiation on Si substrates is examined in both laser-irradiated and nonirradiated areas using Raman scattering, Rayleigh scattering, and by photoluminescence (PL), as a function of temperature, and by TEM. The temperature dependence of the PL and Raman peak positions indicates the presence of compressive stress in the thin GaAs films in both laser-irradiated and nonirradiated areas. This indicates incomplete homogeneous strain relaxation by dislocations at the growth temperature. The residual compressive strain at the growth temperature is large enough such that even with the introduction of tensile strain arising from the difference in thermal expansion coefficients of GaAs and Si, a compressive strain is still present at room temperature for these thin GaAs/Si films.

  9. Enhanced detection of a low-frequency signal by using broad squeezed light and a bichromatic local oscillator

    Science.gov (United States)

    Li, Wei; Jin, Yuanbin; Yu, Xudong; Zhang, Jing

    2017-08-01

    We experimentally study a protocol of using the broadband high-frequency squeezed vacuum to detect the low-frequency signal. In this scheme, the lower sideband field of the squeezed light carries the low-frequency modulation signal, and the two strong coherent light fields are applied as the bichromatic local oscillator in the homodyne detection to measure the quantum entanglement of the upper and lower sideband for the broadband squeezed light. The power of one of the local oscillators for detecting the upper sideband can be adjusted to optimize the conditional variance in the low-frequency regime by subtracting the photocurrent of the upper sideband field of the squeezed light from that of the lower sideband field. By means of the quantum correlation of the upper and lower sideband for the broadband squeezed light, the low-frequency signal beyond the standard quantum limit is measured. This scheme is appropriate for enhancing the sensitivity of the low-frequency signal by the aid of the broad squeezed light, such as gravitational waves detection, and does not need to directly produce the low-frequency squeezing in an optical parametric process.

  10. Using galaxy pairs to investigate the three-point correlation function in the squeezed limit

    Science.gov (United States)

    Yuan, Sihan; Eisenstein, Daniel J.; Garrison, Lehman H.

    2017-11-01

    We investigate the three-point correlation function (3PCF) in the squeezed limit by considering galaxy pairs as discrete objects and cross-correlating them with the galaxy field. We develop an efficient algorithm using fast Fourier transforms to compute such cross-correlations and their associated pair-galaxy bias bp, g and the squeezed 3PCF coefficient Qeff. We implement our method using N-body cosmological simulations and a fiducial halo occupation distribution (HOD) and present the results in both the real space and redshift space. In real space, we observe a peak in bp, g and Qeff at pair separation of ∼2 Mpc, attributed to the fact that galaxy pairs at 2 Mpc separation trace the most massive dark matter haloes. We also see strong anisotropy in the bp, g and Qeff signals that track the large-scale filamentary structure. In redshift space, both the 2 Mpc peak and the anisotropy are significantly smeared out along the line of sight due to finger-of-God effect. In both the real space and redshift space, the squeezed 3PCF shows a factor of 2 variation, contradicting the hierarchical ansatz, but offering rich information on the galaxy-halo connection. Thus, we explore the possibility of using the squeezed 3PCF to constrain the HOD. When we compare two simple HOD models that are closely matched in their projected two-point correlation function (2PCF), we do not yet see a strong variation in the 3PCF that is clearly disentangled from variations in the projected 2PCF. Nevertheless, we propose that more complicated HOD models, e.g. those incorporating assembly bias, can break degeneracies in the 2PCF and show a distinguishable squeezed 3PCF signal.

  11. Absorption spectrum of a two-level atom in a bad cavity with injected squeezed vacuum

    Science.gov (United States)

    Zhou, Peng; Swain, S.

    1996-02-01

    We study the absorption spectrum of a coherently driven two-level atom interacting with a resonant cavity mode which is coupled to a broadband squeezed vacuum through its input-output mirror in the bad cavity limit. We study the modification of the two-photon correlation strength of the injected squeezed vacuum inside the cavity, and show that the equations describing probe absorption in the cavity environment are formally identical to these in free space, but with modified parameters describing the squeezed vacuum. The two photon correlations induced by the squeezed vacuum are always weaker than in free space. We pay particular attention to the spectral behaviour at line centre in the region of intermediate trength driving intensities, where anomalous spectral features such as hole-burning and dispersive profiles are displayed. These unusual spectral features are very sensitive to the squeezing phase and the Rabi frequency of the driving field. We also derive the threshold value of the Rabi frequency which gives rise to the transparency of the probe beam at the driving frequency. When the Rabi frequency is less than the threshold value, the probe beam is absorbed, whilst the probe beam is amplified (without population inversion under certain conditions) when the Rabi frequency is larger than this threshold. The anomalous spectral features all take place in the vicinity of the critical point dividing the different dynamical regimes, probe absorption and amplification, of the atomic radiation. The physical origin of the strong amplification without population inversion, and the feasibility of observing it, are discussed.

  12. Modelling and multi objective optimization of LM13 aluminium alloy squeeze cast process parameters using taguchi and genetic algorithm

    Directory of Open Access Journals (Sweden)

    S. Vellingiri

    2018-01-01

    Full Text Available This present investigation deals with squeeze casting process in order to produce a component with good mechanical properties such as micro-hardness(VH, tensile strength(Rm, and density(ρ on LM13 by varying squeeze pressure(P, molten temperature(Tm and die temperature(Td. Taguchi experimental design L9 orthogonal array was used to determine the signal to noise ratio. The results specified that the squeeze pressure and die preheat temperature are the most influencing parameters for mechanical properties improvement. Genetic algorithm (GA has been applied to optimize the casting parameters that simultaneously maximize the responses.

  13. Analytical solutions by squeezing to the anisotropic Rabi model in the nonperturbative deep-strong-coupling regime

    Science.gov (United States)

    Zhang, Yu-Yu; Chen, Xiang-You

    2017-12-01

    An unexplored nonperturbative deep strong coupling (npDSC) achieved in superconducting circuits has been studied in the anisotropic Rabi model by the generalized squeezing rotating-wave approximation. Energy levels are evaluated analytically from the reformulated Hamiltonian and agree well with numerical ones in a wide range of coupling strength. Such improvement ascribes to deformation effects in the displaced-squeezed state presented by the squeezed momentum variance, which are omitted in previous displaced states. The atom population dynamics confirms the validity of our approach for the npDSC strength. Our approach offers the possibility to explore interesting phenomena analytically in the npDSC regime in qubit-oscillator experiments.

  14. Combined Effect of Piezoviscous Dependency and Non-Newtonian Couple Stress on Squeeze-Film Porous Annular Plate

    Science.gov (United States)

    Vasanth, K. R.; Hanumagowda, B. N.; Santhosh Kumar, J.

    2018-04-01

    Squeeze film investigations focus upon film pressure, load bearing quantity and the minimum thickness of film. The combined effect of pressure viscous dependent and non- Newtonian couple stress in porous annular plate is studied. The modified equations of one dimensional pressure, load bearing quantity, non dimensional squeeze time are obtained. The conclusions obtained in the study are found to be in very good agreement compared to the previous results which are published. The load carrying capacity is increased due to the variation in the pressure dependent viscosity and also due to the couple stress effect. Finally this results in change in the squeeze film timings.

  15. Optimization of squeeze casting parameters for non symmetrical AC2A aluminium alloy castings through Taguchi method

    International Nuclear Information System (INIS)

    Senthil, P.; Amirthagadeswaran, K. S.

    2012-01-01

    This paper reports a research in which an attempt was made to prepare AC2A aluminium alloy castings of a non symmetrical component through squeeze casting process. The primary objective was to investigate the influence of process parameters on mechanical properties of the castings. Experiments were conducted based on orthogonal array suggested in Taguchi's offline quality control concept. The experimental results showed that squeeze pressure, die preheating temperature and compression holding time were the parameters making significant improvement in mechanical properties. The optimal squeeze casting condition was found and mathematical models were also developed for the process

  16. Thin films of molecular materials synthesized from C{sub 32}H{sub 20}N{sub 10}M (M Co, Pb, Fe): Film formation, electrical and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico); Sanchez Vergara, M.E., E-mail: elena.sanchez@anahuac.mx [Coordinacion de Ingenieria Mecatronica, Facultad de Ingenieria, Universidad Anahuac del Norte, Avenida Lomas Anahuac 46, Colonia Lomas Anahuac, 52786, Huixquilucan, Estado de Mexico (Mexico); Garcia Montalvo, V. [Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Ortiz, A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico); Alvarez, J.R. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Ciudad de Mexico, Calle del Puente 222, Colonia Ejidos de Huipulco, 14380 Mexico, D.F. (Mexico)

    2010-03-15

    In this work, the synthesis of molecular materials formed from metallic phthalocyanines and 1,4-phenylenediamine is reported. The powder and thin film ({approx}80-115 nm thickness) samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The morphology of the deposited films was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and their optical and electrical properties were studied as well. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200-1200 nm. The absorption spectra recorded in the UV-vis region for the deposited samples showed two bands, namely the Q and Soret bands. The optical activation energy was calculated and found to be 3.41 eV for the material with cobalt, 3.34 eV for the material including lead and 3.5 eV for the material with iron. The effect of temperature on conductivity was measured for the thin films and the corresponding conduction processes are discussed in this work.

  17. thin films

    Indian Academy of Sciences (India)

    microscopy (SEM) studies, respectively. The Fourier transform ... Thin films; chemical synthesis; hydrous tin oxide; FTIR; electrical properties. 1. Introduction ... dehydrogenation of organic compounds (Hattori et al 1987). .... SEM images of (a) bare stainless steel and (b) SnO2:H2O thin film on stainless steel substrate at a ...

  18. A Monte Carlo Simulation approach for the modeling of free-molecule squeeze-film damping of flexible microresonators

    KAUST Repository

    Leung, Roger

    2010-03-31

    Squeeze-film damping on microresonators is a significant damping source even when the surrounding gas is highly rarefied. This article presents a general modeling approach based on Monte Carlo (MC) simulations for the prediction of squeeze-film damping on resonators in the freemolecule regime. The generality of the approach is demonstrated in its capability of simulating resonators of any shape and with any accommodation coefficient. The approach is validated using both the analytical results of the free-space damping and the experimental data of the squeeze-film damping on a clamped-clamped plate resonator oscillating at its first flexure mode. The effect of oscillation modes on the quality factor of the resonator has also been studied and semi-analytical approximate models for the squeeze-film damping with diffuse collisions have been developed.

  19. Quantum properties of a superposition of squeezed displaced two-mode vacuum and single-photon states

    International Nuclear Information System (INIS)

    El-Orany, Faisal A A; Obada, A-S F; M Asker, Zafer; Perina, J

    2009-01-01

    In this paper, we study some quantum properties of a superposition of displaced squeezed two-mode vacuum and single-photon states, such as the second-order correlation function, the Cauchy-Schwarz inequality, quadrature squeezing, quasiprobability distribution functions and purity. These type of states include two mechanisms, namely interference in phase space and entanglement. We show that these states can exhibit sub-Poissonian statistics, squeezing and deviate from the classical Cauchy-Schwarz inequality. Moreover, the amount of entanglement in the system can be increased by increasing the squeezing mechanism. In the framework of the quasiprobability distribution functions, we show that the single-mode state can tend to the thermal state based on the correlation mechanism. A generation scheme for such states is given.

  20. Control of the inversionless gain and refractive index in a V-type atom via squeezed vacuum and quantum interference

    International Nuclear Information System (INIS)

    Anton, M.A.; Calderon, Oscar G.; Carreno, F.

    2004-01-01

    In this paper we analyze the steady-state populations and gain lineshape of a V-type three-level atom with a closely spaced excited doublet. The atom is driven by a strong coherent field, a weak probe, and a single broadband squeezed vacuum. We focus our attention in the interplay between the quantum interference and the squeezed field on the probe gain. It is shown that the relative phases between the two coherent fields and the squeezed field play an important role in the optical properties of the atom. Specifically, we find that the probe can experience gain without population inversion for proper values of the parameters characterizing the squeezed field and in the absence of incoherent pumping. The system can be tailored to exhibit multiple dispersion regimes accompanied by negligible gain or absorption over a large bandwidth, a desirable feature for obtaining propagation of pulses with negligible distortion

  1. Dye sensitized solar cell applications of CdTiO{sub 3}–TiO{sub 2} composite thin films deposited from single molecular complex

    Energy Technology Data Exchange (ETDEWEB)

    Ehsan, Muhammad Ali [Nanotechnology and Catalysis Centre (NANOCAT), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Khaledi, Hamid [Department of Chemistry, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Pandikumar, Alagarsamy; Huang, Nay Ming [Department of Physics, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Arifin, Zainudin [Department of Chemistry, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Department of Chemistry, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2015-10-15

    A heterobimetallic complex [Cd{sub 2}Ti{sub 4}(μ-O){sub 6}(TFA){sub 8}(THF){sub 6}]·1.5THF (1) (TFA=trifluoroacetato, THF=tetrahydrofuran) comprising of Cd:Ti (1:2) ratio was synthesized by a chemical reaction of cadmium (II) acetate with titanium (IV) isopropoxide and triflouroacetic acid in THF. The stoichiometry of (1) was recognized by single crystal X-ray diffraction, spectroscopic and elemental analyses. Thermal studies revealed that (1) neatly decomposes at 450 °C to furnish 1:1 ratio of cadmium titanate:titania composite oxides material. The thin films of CdTiO{sub 3}–TiO{sub 2} composite oxides were deposited at 550 °C on fluorine doped tin oxide coated conducting glass substrate in air ambient. The micro-structure, crystallinity, phase identification and chemical composition of microspherical architectured CdTiO{sub 3}–TiO{sub 2} composite thin film have been determined by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analysis. The scope of composite thin film having band gap of 3.1 eV was explored as photoanode for dye-sensitized solar cell application. - Graphical abstarct: Microspherical designed CdTiO{sub 3}–TiO{sub 2} composite oxides photoanode film has been fabricated from single source precursor [Cd{sub 2}Ti{sub 4}(μ-O){sub 6}(TFA){sub 8}(THF){sub 6}]·1.5THF via aerosol assisted chemical vapor deposition technique for dye sensitized solar cell application. - Highlights: • Synthesis and characterization of a heterobimetallic Cd–Ti complex. • Fabrication of CdTiO{sub 3}–TiO{sub 2} thin film photoelectrode. • Application as dye sensitized photoanode for solar application.

  2. Single and two-mode mechanical squeezing of an optically levitated nanodiamond via dressed-state coherence

    International Nuclear Information System (INIS)

    Ge, Wenchao; Bhattacharya, M

    2016-01-01

    Nonclassical states of macroscopic objects are promising for ultrasensitive metrology as well as testing quantum mechanics. In this work, we investigate dissipative mechanical quantum state engineering in an optically levitated nanodiamond. First, we study single-mode mechanical squeezed states by magnetically coupling the mechanical motion to a dressed three-level system provided by a nitrogen-vacancy center in the nanoparticle. Quantum coherence between the dressed levels is created via microwave fields to induce a two-phonon transition, which results in mechanical squeezing. Remarkably, we find that in ultrahigh vacuum quantum squeezing is achievable at room temperature with feedback cooling. For moderate vacuum, quantum squeezing is possible with cryogenic temperature. Second, we present a setup for two mechanical modes coupled to the dressed three levels, which results in two-mode squeezing analogous to the mechanism of the single-mode case. In contrast to previous works, our study provides a deterministic method for engineering macroscopic squeezed states without the requirement for a cavity. (paper)

  3. Single and two-mode mechanical squeezing of an optically levitated nanodiamond via dressed-state coherence

    Science.gov (United States)

    Ge, Wenchao; Bhattacharya, M.

    2016-10-01

    Nonclassical states of macroscopic objects are promising for ultrasensitive metrology as well as testing quantum mechanics. In this work, we investigate dissipative mechanical quantum state engineering in an optically levitated nanodiamond. First, we study single-mode mechanical squeezed states by magnetically coupling the mechanical motion to a dressed three-level system provided by a nitrogen-vacancy center in the nanoparticle. Quantum coherence between the dressed levels is created via microwave fields to induce a two-phonon transition, which results in mechanical squeezing. Remarkably, we find that in ultrahigh vacuum quantum squeezing is achievable at room temperature with feedback cooling. For moderate vacuum, quantum squeezing is possible with cryogenic temperature. Second, we present a setup for two mechanical modes coupled to the dressed three levels, which results in two-mode squeezing analogous to the mechanism of the single-mode case. In contrast to previous works, our study provides a deterministic method for engineering macroscopic squeezed states without the requirement for a cavity.

  4. Fractals as macroscopic manifestation of squeezed coherent states and brain dynamics

    International Nuclear Information System (INIS)

    Vitiello, Giuseppe

    2012-01-01

    Recent results on the relation between self-similarity and squeezed coherent states are presented. I consider fractals which are generated iteratively according to a prescribed recipe, the so-called deterministic fractals. Fractal properties are incorporated in the framework of the theory of the entire analytical functions and deformed coherent states. Conversely, fractal properties of squeezed coherent states are recognized. This sheds some light on the understanding of the dynamical origin of fractals and their global nature emerging from local deformation processes. The self-similarity in brain background activity suggested by laboratory observations of power-law distributions of power spectral densities of electrocorticograms is also discussed and accounted in the frame of the dissipative many-body model of brain.

  5. O(N) symmetries, sum rules for generalized Hermite polynomials and squeezed states

    International Nuclear Information System (INIS)

    Daboul, Jamil; Mizrahi, Salomon S

    2005-01-01

    Quantum optics has been dealing with coherent states, squeezed states and many other non-classical states. The associated mathematical framework makes use of special functions as Hermite polynomials, Laguerre polynomials and others. In this connection we here present some formal results that follow directly from the group O(N) of complex transformations. Motivated by the squeezed states structure, we introduce the generalized Hermite polynomials (GHP), which include as particular cases, the Hermite polynomials as well as the heat polynomials. Using generalized raising operators, we derive new sum rules for the GHP, which are covariant under O(N) transformations. The GHP and the associated sum rules become useful for evaluating Wigner functions in a straightforward manner. As a byproduct, we use one of these sum rules, on the operator level, to obtain raising and lowering operators for the Laguerre polynomials and show that they generate an sl(2, R) ≅ su(1, 1) algebra

  6. Decoherence and Fidelity in Teleportation of Coherent Photon-Added Two-Mode Squeezed Thermal States

    Science.gov (United States)

    Li, Heng-Mei; Yuan, Hong-Chun; Wan, Zhi-Long; Wang, Zhen

    2018-04-01

    We theoretically introduce a kind of non-Gaussian entangled resources, i.e., coherent photon-added two-mode squeezed thermal states (CPA-TMSTS), by successively performing coherent photon addition operation to the two-mode squeezed thermal states. The normalization factor related to bivariate Hermite polynomials is obtained. Based upon it, the nonclassicality and decoherence process are analyzed by virtue of the Wigner function. It is shown that the coherent photon addition operation is an effective way in generating partial negative values of Wigner function, which clearly manifests the nonclassicality and non-Gaussianity of the target states. Additionally, the fidelity in teleporting coherent states using CPA-TMSTS as entangled resource is quantified both analytically and numerically. It is found that the CPA-TMSTS is an entangled resource of high-efficiency and high-fidelity in quantum teleportation.

  7. Back-action evasion and squeezing of a mechanical resonator using a cavity detector

    Energy Technology Data Exchange (ETDEWEB)

    Clerk, A A [Department of Physics, McGill University, Montreal, Quebec, H3A 2T8 (Canada); Marquardt, F [Department of Physics, Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitaet Muenchen, Theresienstrasse 37, 80333 Munich (Germany); Jacobs, K [Department of Physics, University of Massachussets at Boston, Boston, MA 02125 (United States)], E-mail: aashish.clerk@mcgill.ca, E-mail: florian.marquardt@physik.uni-muenchen.de, E-mail: kjacobs@cs.umb.edu

    2008-09-15

    We study the quantum measurement of a cantilever using a parametrically coupled electromagnetic cavity which is driven at the two sidebands corresponding to the mechanical motion. This scheme, originally due to Braginsky et al (Braginsky V, Vorontsov Y I and Thorne K P 1980 Science 209 547), allows a back-action free measurement of one quadrature of the cantilever's motion, and hence the possibility of generating a squeezed state. We present a complete quantum theory of this system, and derive simple conditions on when the quantum limit on the added noise can be surpassed. We also study the conditional dynamics of the measurement, and discuss how such a scheme (when coupled with feedback) can be used to generate and detect squeezed states of the oscillator. Our results are relevant to experiments in optomechanics, and to experiments in quantum electromechanics employing stripline resonators coupled to mechanical resonators.

  8. Plasmonic Moon: a Fano-like approach for squeezing the magnetic field in the infrared

    KAUST Repository

    Panaro, Simone

    2015-08-11

    Outstanding results have been achieved in the localization of optical electric fields via ultrasmall plasmonic cavities, paving the way to the subdiffractive confinement of local electromagnetic fields. However, due to the intrinsic constraints related to conventional architectures, no comparable squeezing factors have been managed yet for the magnetic counterpart of radiation, practically hindering the detection and manipulation of magneto-optical effects at the nanoscale. Here, we observe a strong magnetic field nanofocusing in the infrared, promoted by the induction of a coil-type Fano resonance. By triggering the coil current via a quadrupole-like plasmonic mode, we straightforwardly boost the enhancement of the infrared magnetic field and perform its efficient squeezing in localized nanovolumes.

  9. Quantum key distribution with a single photon from a squeezed coherent state

    International Nuclear Information System (INIS)

    Matsuoka, Masahiro; Hirano, Takuya

    2003-01-01

    Squeezing of the coherent state by optical parametric amplifier is shown to efficiently produce single-photon states with reduced multiphoton probabilities compared with the weak coherent light. It can be a better source for a longer-distance quantum key distribution and also for other quantum optical experiments. The necessary condition for a secure quantum key distribution given by Brassard et al. is analyzed as functions of the coherent-state amplitude and squeeze parameter. Similarly, the rate of the gained secure bits G after error correction and privacy amplification given by Luetkenhaus is calculated. Compared with the weak coherent light, it is found that G is about ten times larger and its high level continues on about two times longer distance. By improvement of the detector efficiency it is shown that the distance extends further. Measurement of the intensity correlation function and the relation to photon antibunching are discussed for the experimental verification of the single-photon generation

  10. Quantum cooling and squeezing of a levitating nanosphere via time-continuous measurements

    Science.gov (United States)

    Genoni, Marco G.; Zhang, Jinglei; Millen, James; Barker, Peter F.; Serafini, Alessio

    2015-07-01

    With the purpose of controlling the steady state of a dielectric nanosphere levitated within an optical cavity, we study its conditional dynamics under simultaneous sideband cooling and additional time-continuous measurement of either the output cavity mode or the nanosphere’s position. We find that the average phonon number, purity and quantum squeezing of the steady-states can all be made more non-classical through the addition of time-continuous measurement. We predict that the continuous monitoring of the system, together with Markovian feedback, allows one to stabilize the dynamics for any value of the laser frequency driving the cavity. By considering state of the art values of the experimental parameters, we prove that one can in principle obtain a non-classical (squeezed) steady-state with an average phonon number {n}{ph}≈ 0.5.

  11. Entanglement concentration and purification of two-mode squeezed microwave photons in circuit QED

    Science.gov (United States)

    Zhang, Hao; Alsaedi, Ahmed; Hayat, Tasawar; Deng, Fu-Guo

    2018-04-01

    We present a theoretical proposal for a physical implementation of entanglement concentration and purification protocols for two-mode squeezed microwave photons in circuit quantum electrodynamics (QED). First, we give the description of the cross-Kerr effect induced between two resonators in circuit QED. Then we use the cross-Kerr media to design the effective quantum nondemolition (QND) measurement on microwave-photon number. By using the QND measurement, the parties in quantum communication can accomplish the entanglement concentration and purification of nonlocal two-mode squeezed microwave photons. We discuss the feasibility of our schemes by giving the detailed parameters which can be realized with current experimental technology. Our work can improve some practical applications in continuous-variable microwave-based quantum information processing.

  12. Relieving the Time Squeeze? Effects of a White-Collar Workplace Change on Parents.

    Science.gov (United States)

    Hill, Rachelle; Tranby, Eric; Kelly, Erin; Moen, Phyllis

    2013-08-01

    Employed parents perceive a time squeeze even as trends from the 1960s show they are spending more time with their children. Work conditions (e.g., hours and schedule control) would seem to affect both parents' time with children and perceived time squeeze, but most studies rely on cross-sectional data that do not establish causality. The authors examined the effects of the introduction of a workplace flexibility initiative (Results Only Work Environment [ROWE]) on changes in mothers' and fathers' perceptions of the adequacy of their time with children and actual time spent with children ( N = 225). Baseline data show the importance of work conditions for parents' sense of perceived time adequacy. Panel data show that mothers (but not fathers) in ROWE report increased schedule control and improved time adequacy, but no change in actual time spent with children, except that ROWE increases evening meals with children for mothers sharing few meals at baseline.

  13. Squeezed Dirac and Topological Magnons in a Bosonic Honeycomb Optical Lattice.

    Science.gov (United States)

    Owerre, Solomon; Nsofini, Joachim

    2017-09-20

    Quantum information storage using charge-neutral quasiparticles are expected to play a crucial role in the future of quantum computers. In this regard, magnons or collective spin-wave excitations in solid-state materials are promising candidates in the future of quantum computing. Here, we study the quantum squeezing of Dirac and topological magnons in a bosonic honeycomb optical lattice with spin-orbit interaction by utilizing the mapping to quantum spin-$1/2$ XYZ Heisenberg model on the honeycomb lattice with discrete Z$_2$ symmetry and a Dzyaloshinskii-Moriya interaction. We show that the squeezed magnons can be controlled by the Z$_2$ anisotropy and demonstrate how the noise in the system is periodically modified in the ferromagnetic and antiferromagnetic phases of the model. Our results also apply to solid-state honeycomb (anti)ferromagnetic insulators. . © 2017 IOP Publishing Ltd.

  14. Cooling and squeezing the fluctuations of a nanomechanical beam by indirect quantum feedback control

    International Nuclear Information System (INIS)

    Zhang Jing; Liu Yuxi; Nori, Franco

    2009-01-01

    We study cooling and squeezing the fluctuations of a nanomechanical beam using quantum feedback control. In our model, the nanomechanical beam is coupled to a transmission line resonator via a superconducting quantum interference device. The leakage of the electromagnetic field from the transmission line resonator is measured using homodyne detection. This measured signal is then used to design a quantum feedback control signal to drive the electromagnetic field in the transmission line resonator. Although the control is imposed on the transmission line resonator, this quantum feedback control signal indirectly affects the thermal motion of the nanomechanical beam via the inductive beam-resonator coupling, making it possible to cool and squeeze the fluctuations of the beam, allowing it to approach the standard quantum limit.

  15. Polarization Behavior of Squeeze Cast Al2O3 Fiber Reinforced Aluminum Matrix Composites

    International Nuclear Information System (INIS)

    Ham, S. H.; Kang, Y. C.; Cho, K. M.; Park, I. M.

    1992-01-01

    Electrochemical polarization behavior of squeeze cast Al 2 O 3 short fiber reinforced Al alloy matrix composites was investigated for the basic understanding of the corrosion properties of the composites. The composites were fabricated with variations of fiber volume fraction and matrix alloys. It was found that the reinforced composites are more susceptible to corrosion attack than the unreinforced matrix alloys in general. Corrosion resistance shows decreasing tendency with increasing Al 2 O 3 fiber volume fraction in AC8A matrix. Effect of the matrix alloys revealed that the AC8A Al matrix composite is less susceptible to corrosion attack than the 2024 and 7075 Al matrix composites. Effect of plastic deformation on electrochemical polarization behavior of the squeeze cast Al/Al 2 O 3 composites was examined after extrusion of AC8A-10v/o Al 2 O 3 . Result shows that corrosion resistance is deteriorated after plastic deformation

  16. Mechanism and application of a newly developed pressure casting process: horizontal squeeze casting

    Directory of Open Access Journals (Sweden)

    Li Peijie

    2014-07-01

    Full Text Available Compared to traditional high-pressure die casting (HPDC, horizontal squeeze casting (HSC is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity filling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. Furthermore, numerical simulation is used to analyze the three fundamental characteristics of HSC: slow cavity filling, squeeze feeding and slow sleeve filling. From this, a selection principle is given based on the three related critical casting parameters: cavity filling velocity, gate size and sleeve filling velocity. Finally, two specific applications of HSC are introduced, and the future direction of HSC development is discussed.

  17. Squeezed Dirac and topological magnons in a bosonic honeycomb optical lattice

    Science.gov (United States)

    Owerre, S. A.; Nsofini, J.

    2017-11-01

    Quantum information storage using charge-neutral quasiparticles is expected to play a crucial role in the future of quantum computers. In this regard, magnons or collective spin-wave excitations in solid-state materials are promising candidates in the future of quantum computing. Here, we study the quantum squeezing of Dirac and topological magnons in a bosonic honeycomb optical lattice with spin-orbit interaction by utilizing the mapping to quantum spin-1/2 XYZ Heisenberg model on the honeycomb lattice with discrete Z2 symmetry and a Dzyaloshinskii-Moriya interaction. We show that the squeezed magnons can be controlled by the Z2 anisotropy and demonstrate how the noise in the system is periodically modified in the ferromagnetic and antiferromagnetic phases of the model. Our results also apply to solid-state honeycomb (anti)ferromagnetic insulators.

  18. Quantum mechanical noise in coherent-state and squeezed-state Michelson interferometers

    International Nuclear Information System (INIS)

    Assaf, Ohad; Ben-Aryeh, Yacob

    2002-01-01

    In the present study we extend and generalize previous results for coherent-state and squeezed-state Michelson interferometer quantum mechanical uncertainties (or fluctuations), which are commonly referred to as 'quantum noise'. The calculation of photon counting (PC) fluctuations in the squeezed-state interferometer is extended to fourth-order correlation functions used as the measured signal. We also generalize a 'unified model' for treating both PC and radiation pressure fluctuations in the coherent-state interferometer, by using mathematical methods which apply to Kerr-type interactions. The results are more general than those reported previously in two ways. First, we obtain exact expressions, which lead to previous results under certain approximations. Second, we deal with cases in which the responses of the two mirrors to radiation pressure are not equal

  19. Modeling of magnetorheological fluid in quasi-static squeeze flow mode

    Science.gov (United States)

    Horak, Wojciech

    2018-06-01

    This work presents a new nonlinear model to describe MR fluid behavior in the squeeze flow mode. The basis for deriving the model were the principles of continuum mechanics and the theory of tensor transformation. The analyzed case concerned quasi-static squeeze with a constant area, between two parallel plates with non-slip boundary conditions. The developed model takes into account the rheological properties or MR fluids as a viscoplastic material for which yield stress increases due to compression. The model also takes into account the formation of normal force in the MR fluid as a result of the magnetic field impact. Moreover, a new parameter has been introduced which characterizes the behavior of MR fluid subjected to compression. The proposed model has been experimentally validated and the obtained results suggest that the assumptions made in the model development are reasonable, as good model compatibility with the experiments was obtained.

  20. Water-based squeezing flow in the presence of carbon nanotubes between two parallel disks

    Directory of Open Access Journals (Sweden)

    Haq Rizwan Ul

    2016-01-01

    Full Text Available Present study is dedicated to investigate the water functionalized carbon nanotubes squeezing flow between two parallel discs. Moreover, we have considered magnetohydrodynamics effects normal to the disks. In addition we have considered two kind of carbon nanotubes named: single wall carbon nanotubes (SWCNT and multiple wall carbon nanotubes (MWCNT with in the base fluid. Under this squeezing flow mechanism model has been constructed in the form of partial differential equation. Transformed ordinary differential equations are solved numerically with the help of Runge-Kutta-Fehlberg method. Results for velocity and temperature are constructed against all the emerging parameters. Comparison among the SWCNT and MWCNT are drawn for skin friction coefficient and local Nusselt number. Conclusion remarks are drawn under the observation of whole analysis.