Formation of positron-atom bound states in collisions between Rydberg Ps and neutral atoms
Swann, A R; Deller, A; Gribakin, G F
2016-01-01
Predicted twenty years ago, positron binding to neutral atoms has not yet been observed experimentally. A new scheme is proposed to detect positron-atom bound states by colliding Rydberg positronium (Ps) with neutral atoms. Estimates of the charge-transfer-reaction cross section are obtained using the first Born approximation for a selection of neutral atom targets and a wide range of incident Ps energies and principal quantum numbers. We also estimate the corresponding Ps ionization cross section. The accuracy of the calculations is tested by comparison with earlier predictions for Ps charge transfer in collisions with hydrogen and antihydrogen. We describe an existing Rydberg Ps beam suitable for producing positron-atom bound states and estimate signal rates based on the calculated cross sections and realistic experimental parameters. We conclude that the proposed methodology is capable of producing such states and of testing theoretical predictions of their binding energies.
A tabulation of the bound-state energies of atomic hydrogen
Horbatsch, M
2016-01-01
We present tables for the bound-state energies for atomic hydrogen. The tabulated energies include the hyperfine structure, and thus this work extends the work of Rev. Mod. Phys. {\\bf 84}, 1527 (2012), which excludes hyperfine structure. The tabulation includes corrections of the hyperfine structure due to the anomalous moment of the electron, due to the finite mass of the proton, and due to off-diagonal matrix elements of the hyperfine Hamiltonian. These corrections are treated incorrectly in most other works. Simple formulas valid for all quantum numbers are presented for the hyperfine corrections. The tabulated energies have uncertainties of less than 1 kHz for all states. This accuracy is possible because of the recent precision measurement [Nature, {\\bf 466}, 213 (2010); Science, {\\bf 339}, 417] of the proton radius. The effect of this new radius on the energy levels is also tabulated, and the energies are compared to precision measurements of atomic hydrogen energy intervals.
Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States
Directory of Open Access Journals (Sweden)
Hadizadeh M.R.
2010-04-01
Full Text Available The ﬁrst step toward the application of an eﬀective non partial wave (PW numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momentum vectors, i.e. as a function of the magnitude of initial and ﬁnal momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully oﬀ-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole.
Sulfur Atom in its Bound State Is a Unique Element Involved in Physiological Functions in Mammals
Directory of Open Access Journals (Sweden)
Shin Koike
2016-12-01
Full Text Available It was in the 1950s that the term polysulfide or persulfide was introduced in biological studies. The unfamiliar term “sulfane sulfur” sometimes appeared in papers published in the 1970s, and was defined in the review article by Westley in 1983. In the article, sulfane sulfur is described as sulfur atoms that are covalently bound only with sulfur atoms, and as this explanation was somewhat difficult to comprehend, it was not generally accepted. Thus, in the early 1990s, we redefined these sulfur species as “bound sulfur”, which easily converts to hydrogen sulfide on reduction with a thiol reducing agent. In other words, bound sulfur refers to a sulfur atom that exists in a zero to divalent form (0 to −2. The first part of this review focuses on the fluorescent derivatization HPLC method—which we developed for measurement of bound sulfur—and explains the distribution of bound sulfur and the hydrogen sulfide-producing ability of various tissues, as clarified by this method. Next, we discuss diverse physiological functions and involvement of polysulfide, a typical type of bound sulfur, in the redox regulation system. Additionally, we also address its possible physiological role in the central nervous system, based on its action of scavenging reactive carbonyl compounds.
Inversion symmetry breaking of atomic bound states in strong and short laser fields
Stooß, Veit; Ott, Christian; Blättermann, Alexander; Ding, Thomas; Pfeifer, Thomas
2015-01-01
In any atomic species, the spherically symmetric potential originating from the charged nucleus results in fundamental symmetry properties governing the structure of atomic states and transition rules between them. If atoms are exposed to external electric fields, these properties are modified giving rise to energy shifts such as the AC Stark-effect in varying fields and, contrary to this in a constant (DC) electric field for high enough field strengths, the breaking of the atomic symmetry which causes fundamental changes in the atom's properties. This has already been observed for atomic Rydberg states with high principal quantum numbers. Here, we report on the observation of symmetry breaking effects in Helium atoms for states with principal quantum number n=2 utilizing strong visible laser fields. These findings were enabled by temporally resolving the dynamics better than the sub-optical cycle of the applied laser field, utilizing the method of attosecond transient absorption spectroscopy (ATAS). We ident...
Hoyer, Paul
2017-05-01
Bound state poles in the S-matrix of perturbative QED are generated by the divergence of the expansion in α . The perturbative corrections are necessarily singular when expanding around free, {O}( α ^0 ) in and out states that have no overlap with finite-sized atomic wave functions. Nevertheless, measurables such as binding energies do have well-behaved expansions in powers of α (and log α ). It is desirable to formulate the concept of "lowest order" for gauge theory bound states such that higher order corrections vanish in the α → 0 limit. This may allow to determine a lowest order term for QCD hadrons which incorporates essential features such as confinement and chiral symmetry breaking, and thus can serve as the starting point of a useful perturbative expansion. I discuss a "Born" (no loop, lowest order in \\hbar ) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. Gauss' law determines a distinct field A^0({\\varvec{x}}) for each instantaneous position of the charges. A Poincaré covariant boundary condition for the gluon field leads to a confining potential for q\\bar{q} and qqq states. In frames where the bound state is in motion the classical gauge field is obtained by a Lorentz boost of the rest frame field.
Bound states and the Bekenstein bound
Energy Technology Data Exchange (ETDEWEB)
Bousso, Raphael
2003-10-16
We explore the validity of the generalized Bekenstein bound, S<= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width alpha. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.
Energy Technology Data Exchange (ETDEWEB)
Maccari, Attilio
2003-03-01
The asymptotic perturbation (AP) method is applied to the study of the nonlinear Klein-Gordon equation in 3+1 dimensions with harmonic potential and external periodic excitation supposed to be in primary resonance with the frequency of a generic mode. The AP method uses two different procedures for the solutions: introducing an asymptotic temporal rescaling and balancing of the harmonic terms with a simple iteration. Standard quantum mechanics can be used to derive the lowest order approximate solution and amplitude and phase modulation equations are obtained. External force-response and frequency-response curves are found and the existence of dromions trapped in bound states is demonstrated.
Yamazaki, T
2000-01-01
A new type of nuclear spectroscopy to study hadron-nucleus bound states is described. The first successful experiment was to search for deeply bound pi sup - states in heavy nuclei using the sup 2 sup 0 sup 8 Pb(d, sup 3 He) reaction at GSI, in which a narrow peak arising from the 2p pi sup - orbital coupled with the neutron-hole states was observed at 135 MeV excitation energy. An improved experiment has just been carried out to separately identify the 1s and 2p pi sup - states. These experiments provide important information on the local potential strength, from which the effective mass of pi sup - is deduced to be 20 MeV. This method will be extended to search for eta and omega bound states as well as for K sup - bound states. The advantage of the bound-state spectroscopy versus invariant mass spectroscopy is emphasized.
Bound anionic states of adenine
Energy Technology Data Exchange (ETDEWEB)
Haranczyk, Maciej; Gutowski, Maciej S; Li, Xiang; Bowen, Kit H
2007-03-20
Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases, are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the new-found anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The discovery of these valence anionic states of adenine was facilitated by the development of: (i) a new experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (ii) a new combinatorial/ quantum chemical approach for identification of the most stable tautomers of organic molecules. The computational portion of this work was supported by the: (i) Polish State Committee for Scientific Research (KBN) Grants: DS/8000-4-0140-7 (M.G.) and N204 127 31/2963 (M.H.), (ii) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.), and (iii) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic
Spectral singularities and zero energy bound states
Energy Technology Data Exchange (ETDEWEB)
Heiss, W.D. [National Institute for Theoretical Physics, Stellenbosch Institute for Advanced Study, and Institute of Theoretical Physics, University of Stellenbosch, 7602 Matieland (South Africa); Nazmitdinov, R.G. [Department de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)
2011-08-15
Single particle scattering around zero energy is re-analysed in view of recent experiments with ultra-cold atoms, nano-structures and nuclei far from the stability valley. For non-zero orbital angular momentum the low energy scattering cross section exhibits dramatic changes depending on the occurrence of either a near resonance or a bound state or the situation in between, that is a bound state at zero energy. Such state is singular in that it has an infinite scattering length, behaves for the eigenvalues but not for the eigenfunctions as an exceptional point and has no pole in the scattering function. These results should be observable whenever the interaction or scattering length can be controlled. (authors)
Wronskian method for bound states
Energy Technology Data Exchange (ETDEWEB)
Fernandez, Francisco M, E-mail: fernande@quimica.unlp.edu.ar [INIFTA (UNLP, CONICET), Division Quimica Teorica, Boulevard 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)
2011-05-15
We propose a simple and straightforward method based on Wronskians for the calculation of bound-state energies and wavefunctions of one-dimensional quantum-mechanical problems. We explicitly discuss the asymptotic behaviour of the wavefunction and show that the allowed energies make the divergent part vanish. As illustrative examples we consider an exactly solvable model, the Gaussian potential well, and a two-well potential proposed earlier for the interpretation of the infrared spectrum of ammonia.
In-medium K̄ interactions and bound states
Directory of Open Access Journals (Sweden)
Gal Avraham
2014-01-01
Full Text Available Correct treatment of subthreshold K̄ N dynamics is mandatory in K− -atom and K̄ -nuclear bound-state calculations, as demonstrated by using in-medium chirally-based models of K̄ N interactions. Recent studies of kaonic atom data reveal appreciable multi-nucleon contributions. K̄ -nuclear widths larger than 50 MeV are anticipated.
Atomic Stretch: Optimally bounded real-time stretching and beyond
DEFF Research Database (Denmark)
Jensen, Rasmus Ramsbøl; Nielsen, Jannik Boll
2016-01-01
Atomic Stretch is a plugin for your preferred Adobe video editing tool, allowing real-time smooth and optimally bounded retarget-ting from and to any aspect ratio. The plugin allows preserving of high interest pixels through a protected region, attention redirection through color-modification, co......Atomic Stretch is a plugin for your preferred Adobe video editing tool, allowing real-time smooth and optimally bounded retarget-ting from and to any aspect ratio. The plugin allows preserving of high interest pixels through a protected region, attention redirection through color...
Instanton bound states in ABJM theory
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2013-06-15
The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.
Bounds on collapse models from cold-atom experiments
Bilardello, Marco; Donadi, Sandro; Vinante, Andrea; Bassi, Angelo
2016-11-01
The spontaneous localization mechanism of collapse models induces a Brownian motion in all physical systems. This effect is very weak, but experimental progress in creating ultracold atomic systems can be used to detect it. In this paper, we considered a recent experiment (Kovachy et al., 2015), where an atomic ensemble was cooled down to picokelvins. Any Brownian motion induces an extra increase of the position variance of the gas. We study this effect by solving the dynamical equations for the Continuous Spontaneous Localizations (CSL) model, as well as for its non-Markovian and dissipative extensions. The resulting bounds, with a 95 % of confidence level, are beaten only by measurements of spontaneous X-ray emission and by experiments with cantilever (in the latter case, only for rC ≥ 10-7 m, where rC is one of the two collapse parameters of the CSL model). We show that, contrary to the bounds given by X-ray measurements, non-Markovian effects do not change the bounds, for any reasonable choice of a frequency cutoff in the spectrum of the collapse noise. Therefore the bounds here considered are more robust. We also show that dissipative effects are unimportant for a large spectrum of temperatures of the noise, while for low temperatures the excluded region in the parameter space is the more reduced, the lower the temperature.
Energy Technology Data Exchange (ETDEWEB)
Fechner, Peer Cornelis
2015-07-21
The central topic of this thesis is the experimental observation and the theoretical modeling of non-adiabatic three-body dissociation of H{sub 3} and D{sub 3} neutral triatomic hydrogen molecules. Our goal is to lend a meaning to the observed momentum vector correlation (MVC) of the three emerging ground state hydrogen atoms, for example H{sub 3}→H(1s)+H(1s)+H(1s), in terms of symmetries of the nuclear molecular wave function and of the non-adiabatic coupling which initiates this decay. In many experiments carried out over the years, a wealth of state specific MVCs was collected by different research groups. The MVCs are imaged in form of so-called Dalitz plots which show a rich structure of maxima and nodal lines, depending on the initial state of the triatomic hydrogen neutral. Theory was slow to catch up with experiment and only by this year, 2015, a general agreement was accomplished. Nevertheless, these models lack of an easy understanding of the underlying physics as many numerical calculations are involved. The theoretical model presented in this thesis follows a different approach which is more guided by the imaging character of our experiments. We concentrate on a rather qualitative treatment by limiting ourselves to the essential ingredients only. This proceeding contributes to giving a physical interpretation of the structures in the Dalitz plots in the following form: Three-particle coincident imaging offers a direct view of the emerging spatial continuum wave function of a predissociating triatomic molecule as it evolves from molecular spatial dimensions into the realm of independent free particles. This latter result is discussed in the context of the so-called Imaging Theorem, the second main part of this work. A third major part of this thesis pertains to obtaining molecular momentum wave functions in separated degrees-of-freedom via Fourier transformation. Even for triatomic hydrogen - the most simple polyatomic molecule - this is a challenging
Measurement of the Magnetic Moment of the Negative Muon Bound in Different Atoms
Mamedov, T N; Gritsaj, K I; Kormann, O; Major, J V; Stoikov, A V; Zimmermann, U
2001-01-01
Theoretical calculations show that the magnetic moment of the electron and the negative muon in a bound state in an atom should be different from the magnetic moment of the free particle due to their relativistic motion. There are also additional radiative corrections to the magnetic moment of a bound electron (muon) due to the presence of the strong Coulomb field of the atomic nucleus. The results of the measurements of the magnetic moment of the negative muon in carbon, oxygen, magnesium, silicon, sulfur, and zinc are presented. The accuracy of the measurements makes it possible to prove the dependence of the relativistic correction to the magnetic moment of a bound muon on Z of the atom.
Multilevel Atomic Coherent States and Atomic Holomorphic Representation
Cao, Chang-Qi; Haake, Fritz
1996-01-01
The notion of atomic coherent states is extended to the case of multilevel atom collective. Based on atomic coherent states, a holomorphic representation for atom collective states and operators is defined. An example is given to illustrate its application.
Stable Bound States of Asymmetric Dark Matter
Wise, Mark B.; Zhang, Yue
2014-01-01
The simplest renormalizable effective field theories with asymmetric dark matter bound states contain two additional gauge singlet fields one being the dark matter and the other a mediator particle that the dark matter annihilates into. We examine the physics of one such model with a Dirac fermion as the dark matter and a real scalar mediator. For a range of parameters the Yukawa coupling of the dark matter to the mediator gives rise to stable asymmetric dark matter bound states. We derive pr...
Relativistic bound state approach to fundamental forces including gravitation
Directory of Open Access Journals (Sweden)
Morsch H.P.
2012-06-01
Full Text Available To describe the structure of particle bound states of nature, a relativistic bound state formalism is presented, which requires a Lagrangian including scalar coupling of two boson fields. The underlying mechanisms are quite complex and require an interplay of overlapping boson fields and fermion-antifermion production. This gives rise to two potentials, a boson-exchange potential and one identified with the long sought confinement potential in hadrons. With minimal requirements, two elementary massless fermions (quantons - with and without charge - and one gauge boson, hadrons and leptons but also atoms and gravitational systems are described by bound states with electric and magnetic coupling between the charges and spins of quantons. No need is found for colour, Higgs-coupling and supersymmetry.
Verifying bound entanglement of dephased Werner states
Thomas, P.; Bohmann, M.; Vogel, W.
2017-10-01
The verification of quantum entanglement under the influence of realistic noise and decoherence is crucial for the development of quantum technologies. Unfortunately, a full entanglement characterization is generally not possible with most entanglement criteria such as entanglement witnesses or the partial transposition criterion. In particular, so-called bound entanglement cannot be certified via the partial transposition criterion. Here we present the full entanglement verification of dephased qubit and qutrit Werner states via entanglement quasiprobabilities. Remarkably, we are able to reveal bound entanglement for noisy mixed states in the qutrit case. This example demonstrates the strength of the entanglement quasiprobabilities for verifying the full entanglement of quantum states suffering from noise.
Yukawa Bound States and Their LHC Phenomenology
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Enkhbat Tsedenbaljir
2013-01-01
Full Text Available We present the current status on the possible bound states of extra generation quarks. These include phenomenology and search strategy at the LHC. If chiral fourth-generation quarks do exist their strong Yukawa couplings, implied by current experimental lower bound on their masses, may lead to formation of bound states. Due to nearly degenerate 4G masses suggested by Precision Electroweak Test one can employ “heavy isospin” symmetry to classify possible spectrum. Among these states, the color-octet isosinglet vector ω 8 is the easiest to be produced at the LHC. The discovery potential and corresponding decay channels are covered in this paper. With possible light Higgs at ~125 GeV two-Higgs doublet version is briefly discussed.
A note on BPS vortex bound states
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A. Alonso-Izquierdo
2016-02-01
Full Text Available In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
A note on BPS vortex bound states
Energy Technology Data Exchange (ETDEWEB)
Alonso-Izquierdo, A., E-mail: alonsoiz@usal.es [Departamento de Matematica Aplicada, Universidad de Salamanca (Spain); Garcia Fuertes, W., E-mail: wifredo@uniovi.es [Departamento de Fisica, Universidad de Oviedo (Spain); Mateos Guilarte, J., E-mail: guilarte@usal.es [Departamento de Fisica Fundamental, Universidad de Salamanca (Spain)
2016-02-10
In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
Nonvalence Correlation-Bound Anion States of Polycyclic Aromatic Hydrocarbons.
Voora, Vamsee K; Jordan, Kenneth D
2015-10-15
In this work, we characterize the nonvalence correlation-bound anion states of several polycyclic aromatic hydrocarbon (PAH) molecules. Unlike the analogous image potential states of graphene that localize the charge density of the excess electron above and below the plane of the sheet, we find that for PAHs, much of the charge distribution of the excess electron is localized around the periphery of the molecule. This is a consequence of the electrostatic interaction of the electron with the polar CH groups. By replacing the H atoms by F atoms or the CH groups by N atoms, the charge density of the excess electron shifts from the periphery to above and below the plane of the ring systems.
Topological edge states of bound photon pairs
Gorlach, Maxim A.; Poddubny, Alexander N.
2017-05-01
We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. The energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. We link the edge-state existence to the two-photon quantum walk graph connectivity. Our results offer a route to control quantum entanglement and provide insights into the physics of many-body topological states.
Novel black hole bound states and entropy
Govindarajan, T R
2011-01-01
We solve for the spectrum of the Laplacian as Hamiltonian on $\\mathbb{R}^{2}-\\mathbb{D}$ and in $\\mathbb{R}^{3}-\\mathbb{B}$. A self-adjointness analysis with $\\partial\\mathbb{D}$ and $\\partial\\mathbb{B}$ as the boundary for the two cases shows that a general class of boundary conditions for which the Hamiltonian operator is essentially self-adjoint are of the mixed (Robin) type. With this class of boundary conditions we obtain 'bound state' solutions for the Schroedinger equation. Interestingly, these solutions are all localized near the boundary. We further show that the number of bound states is finite and is infact proportional to the perimeter or area of the removed \\emph{disc} or \\emph{ball}. We then argue that similar considerations should hold for static black hole backgrounds with the horizon treated as the boundary.
Closed form bound-state perturbation theory
Directory of Open Access Journals (Sweden)
Ollie J. Rose
1980-01-01
Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.
Analytic continuation of bound states to solve resonance states
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Norimichi; Arai, Koji [Niigata Univ. (Japan); Suzuki, Yoshiyuki; Varga, K.
1997-05-01
As a method to determine the parameters of the resonance state, a method is proposed using analytic continuation on bound constants of correlation. The characteristics of this method consists in probability of prediction of the parameters of the resonance state only by calculation of the bound state. Owing to conducting the analytic continuation on square root of energy in the bound state as a function relating to the bound constant, energy and width in the bound state was determined. Here was reported on a result of application of this method to three systems. Some partial wave on two systems showing correlation at a simple potential and a resonance state of zero of all orbital angular motion quality in three boson system were determined using the analytic continuation method. These results agreed well with one used a method of integrating Schroedinger equation directly and one used the complex scaling method, and this method was found to be much efficient for the study of the resonance state. Under a background of becoming applicable to the method of analytic continuation, there was development of calculating method for the recent small number multi system. As the characteristics of the analytic continuation method is used for only calculation of the bound state, it is convenient at a point applicable to the method to obtain conventional bound state and then is much efficient in a point of applicability of calculus of variations. However, in order to obtain coefficient of Pade approximation correctly, the bound state must be solved correctly, which is difficult for more complex system and is not always applicable to every systems. (G.K.)
Andreev bound states. Some quasiclassical reflections
Energy Technology Data Exchange (ETDEWEB)
Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)
2014-12-15
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.
Surface-bound states in nanodiamonds
Han, Peng; Antonov, Denis; Wrachtrup, Jörg; Bester, Gabriel
2017-05-01
We show via ab initio calculations and an electrostatic model that the notoriously low, but positive, electron affinity of bulk diamond becomes negative for hydrogen passivated nanodiamonds and argue that this peculiar situation (type-II offset with a vacuum level at nearly midgap) and the three further conditions: (i) a surface dipole with positive charge on the outside layer, (ii) a spherical symmetry, and (iii) a dielectric mismatch at the surface, results in the emergence of a peculiar type of surface state localized just outside the nanodiamond. These states are referred to as "surface-bound states" and have consequently a strong environmental sensitivity. These type of states should exist in any nanostructure with negative electron affinity. We further quantify the band offsets of different type of nanostructures as well as the exciton binding energy and contrast the results with results for "conventional" silicon quantum dots.
Bound states in the strong coupling limit
Martin, A
1972-01-01
The author shows that the number of bound states of a particle in a short-range potential in n dimensions is given asymptotically by N=g /sup n/2/S/sub n//(2 pi )/sup n/ integral mod 2MV/sup -//h(cross)/sup 2/ mod /sup n/2/d/sup n/x+0(g/sup n/2-g/) for g to infinity , where gV /sup -/ is the attractive part of the potential, and S/sub /n is the volume of the n dimensional sphere with unit radius. (10 refs).
Engineering the coupling between Majorana bound states
Shi, Z. C.; Shao, X. Q.; Xia, Y.; Yi, X. X.
2017-09-01
We study the coupling between Majorana bound states (CMBS), which is mediated by a topologically trivial chain in the presence of pairing coupling and long-range coupling. The results show that CMBS can be enhanced by the pairing coupling and long-range coupling of the trivial chain. When driving the trivial chain by periodic driving field, we deduce the analytical expressions of CMBS in the high-frequency limit, and demonstrate that CMBS can be modulated by the frequency and amplitude of driving field. Finally we exhibit the application of tunable CMBS in realizing quantum logic gates.
The S-matrix for systems with bound states
Ruijgrok, Th.W.
A unitary S-matrix is defined for a system of three particles, two of which can form a bound state. It is shown how for elastic scattering the polarization of the bound state must be taken into account.
A balance for dark matter bound states
Nozzoli, F.
2017-05-01
Massive particles with self interactions of the order of 0.2 barn/GeV are intriguing Dark Matter candidates from an astrophysical point of view. Current and past experiments for direct detection of massive Dark Matter particles are focusing to relatively low cross sections with ordinary matter, however they cannot rule out very large cross sections, σ/M > 0.01 barn/GeV, due to atmosphere and material shielding. Cosmology places a strong indirect limit for the presence of large interactions among Dark Matter and baryons in the Universe, however such a limit cannot rule out the existence of a small sub-dominant component of Dark Matter with non negligible interactions with ordinary matter in our galactic halo. Here, the possibility of the existence of bound states with ordinary matter, for a similar Dark Matter candidate with not negligible interactions, is considered. The existence of bound states, with binding energy larger than ∼ 1 meV, would offer the possibility to test in laboratory capture cross sections of the order of a barn (or larger). The signature of the detection for a mass increasing of cryogenic samples, due to the possible particle accumulation, would allow the investigation of these Dark Matter candidates with mass up to the GUT scale. A proof of concept for a possible detection set-up and the evaluation of some noise sources are described.
Counting Majorana bound states using complex momenta
Directory of Open Access Journals (Sweden)
I. Mandal
2016-09-01
Full Text Available Recently, the connection between Majorana fermions bound to the defects in arbitrary dimensions, and complex momentum roots of the vanishing determinant of the corresponding bulk Bogoliubov–de Gennes (BdG Hamiltonian, has been established (EPL, 2015, 110, 67005. Based on this understanding, a formula has been proposed to count the number (n of the zero energy Majorana bound states, which is related to the topological phase of the system. In this paper, we provide a proof of the counting formula and we apply this formula to a variety of 1d and 2d models belonging to the classes BDI, DIII and D. We show that we can successfully chart out the topological phase diagrams. Studying these examples also enables us to explicitly observe the correspondence between these complex momentum solutions in the Fourier space, and the localized Majorana fermion wavefunctions in the position space. Finally, we corroborate the fact that for systems with a chiral symmetry, these solutions are the so-called "exceptional points", where two or more eigenvalues of the complexified Hamiltonian coalesce.
Atomic pair-state interferometer
DEFF Research Database (Denmark)
Nipper, J.; Balewski, Jonathan B.; Krupp, Alexander T.
2012-01-01
We present experiments measuring an interaction-induced phase shift of Rydberg atoms at Stark-tuned Förster resonances. The phase shift features a dispersive shape around the resonance, showing that the interaction strength and sign can be tuned coherently. We use a pair-state interferometer...
Robust zero-energy bound states in a helical lattice
Li, Pengke; Sau, Jay D.; Appelbaum, Ian
2017-09-01
Atomic-scale helices exist as motifs for several material lattices. We examine a tight-binding model for a single one-dimensional monatomic chain with a p -orbital basis coiled into a helix. A topologically nontrivial phase emerging from this model supports a chiral symmetry-protected zero-energy mode localized to a boundary, always embedded within a continuum band, regardless of termination site. We identify a topological invariant for this phase that is related to the number of zero energy end modes by means of the bulk-boundary correspondence, and give strict conditions for the existence of the bound state. An additional class of gapped edge modes in the model spectrum has practical consequences for surface states in, e.g., trigonal tellurium and selenium and other van der Waals-bonded one-dimensional semiconductors.
Mapping the orbital structure of impurity bound states in a superconductor.
Choi, Deung-Jang; Rubio-Verdú, Carmen; de Bruijckere, Joeri; Ugeda, Miguel M; Lorente, Nicolás; Pascual, Jose Ignacio
2017-05-08
A magnetic atom inside a superconductor locally distorts superconductivity. It scatters Cooper pairs as a potential with broken time-reversal symmetry, leading to localized bound states with subgap excitation energies, named Shiba states. Most conventional approaches regarding Shiba states treat magnetic impurities as point scatterers with isotropic exchange interaction. Here, we show that the number and the shape of Shiba states are correlated to the spin-polarized atomic orbitals of the impurity, hybridized with the superconductor. Using scanning tunnelling spectroscopy, we spatially map the five Shiba excitations found on subsurface chromium atoms in Pb(111), resolving their particle and hole components. While particle components resemble d orbitals of embedded Cr atoms, hole components differ strongly from them. Density functional theory simulations correlate the orbital shapes to the magnetic ground state of the atom, and identify scattering channels and interactions, all valuable tools for designing atomic-scale superconducting devices.
Bound state in positron scattering by allene
Barbosa, Alessandra Souza; Sanchez, Sergio d'Almeida; Bettega, Márcio H. F.
2017-12-01
We report integral and differential cross sections for positron collisions with allene, calculated with the Schwinger multichannel method. The cross sections were computed in the static-polarization approximation for energies up to 7 eV. We have tested a series of single-particle basis sets and different polarization schemes to improve the description of low-energy positron scattering by the allene molecule. We have found that the use of extra centers with no net charge with additional single-particle s - and p -type functions centered at them are essential in order to accurately reproduce the polarization potential and, hence, obtain proper scattering cross sections. The choice of the allene molecule was due to the fact that it is a highly symmetric molecule with no permanent dipole moment and would allow several different calculations. Our cross sections are compared to the available experimental data for the total cross section with a reasonable agreement after correcting their results due to the low angular discrimination of their apparatus. Also, a virtual state was observed in the integral cross section that became a bound state when the description of the polarization potential is improved. We also observed a Ramsauer-Townsend minimum in the cross section whose location varies from 2.7 to 3.4 eV, depending on the polarization scheme used in the calculations.
Quantum state atomic force microscopy
Passian, Ali; Siopsis, George
2017-01-01
New classical modalities of atomic force microscopy continue to emerge to achieve higher spatial, spectral, and temporal resolution for nanometrology of materials. Here, we introduce the concept of a quantum mechanical modality that capitalizes on squeezed states of probe displacement. We show that such squeezing is enabled nanomechanically when the probe enters the van der Waals regime of interaction with a sample. The effect is studied in the non-contact mode, where we consider the paramete...
Viewing Majorana Bound States by Rabi Oscillations.
Wang, Zhi; Liang, Qi-Feng; Yao, Dao-Xin; Hu, Xiao
2015-07-08
We propose to use Rabi oscillation as a probe to view the fractional Josepshon relation (FJR) associated with Majorana bound states (MBSs) expected in one-dimensional topological superconductors. The system consists of a quantum dot (QD) and an rf-SQUID with MBSs at the Josephson junction. Rabi oscillations between energy levels formed by MBSs are induced by ac gate voltage controlling the coupling between QD and MBS when the photon energy proportional to the ac frequency matches gap between quantum levels formed by MBSs and QD. As a manifestation of the Rabi oscillation in the whole system involving MBSs, the electron occupation on QD oscillates with time, which can be measured by charge sensing techniques. With Floquet theorem and numerical analysis we reveal that from the resonant driving frequency for coherent Rabi oscillation one can directly map out the FJR cos(πΦ/Φ0) as a signature of MBSs, with Φ the magnetic flux through SQUID and Φ0 = hc/2e the flux quantum. The present scheme is expected to provide a clear evidence for MBSs under intensive searching.
Higgs interchange and bound states of superheavy fermions
Indian Academy of Sciences (India)
Hypothetical superheavy fourth-generation fermions with a very small coupling with the rest of the Standard Model can give rise to long enough lived bound states. The production and the detection of these bound states would be experimentally feasible at the LHC. Extending, in the present study, the analysis of other ...
Quasi-bound states, resonance tunnelling, and tunnelling times ...
Indian Academy of Sciences (India)
Abstract. In analogy with the definition of resonant or quasi-bound states used in three-dimensional quantal scattering, we define the quasi-bound states that occur in one- dimensional transmission generated by twin symmetric potential barriers and evaluate their energies and widths using two typical examples: (i) twin ...
Bound states in a hyperbolic asymmetric double-well
Energy Technology Data Exchange (ETDEWEB)
Hartmann, R. R., E-mail: richard.hartmann@dlsu.edu.ph [Physics Department, De La Salle University, 2401 Taft Avenue, Manila (Philippines)
2014-01-15
We report a new class of hyperbolic asymmetric double-well whose bound state wavefunctions can be expressed in terms of confluent Heun functions. An analytic procedure is used to obtain the energy eigenvalues and the criterion for the potential to support bound states is discussed.
Asymptotic-bound-state model for Feshbach resonances
Tiecke, T.G.; Goosen, M.R.; Walraven, J.T.M.; Kokkelmans, S.J.J.M.F.
2010-01-01
We present an asymptotic-bound-state model which can be used to accurately describe all Feshbach resonance positions and widths in a two-body system. With this model we determine the coupled bound states of a particular two-body system. The model is based on analytic properties of the two-body
Parity lifetime of bound states in a proximitized semiconductor nanowire
DEFF Research Database (Denmark)
Higginbotham, Andrew Patrick; Albrecht, Sven Marian; Kirsanskas, Gediminas
2015-01-01
superconductor layer, yielding an isolated, proximitized nanowire segment. We identify Andreev-like bound states in the semiconductor via bias spectroscopy, determine the characteristic temperatures and magnetic fields for quasiparticle excitations, and extract a parity lifetime (poisoning time) of the bound...... state in the semiconductor exceeding 10 ms....
Detecting Majorana nonlocality using strongly coupled Majorana bound states
Rubbert, S.H.P.; Akhmerov, A.R.
2016-01-01
Majorana bound states (MBS) differ from the regular zero energy Andreev bound states in their nonlocal properties, since two MBS form a single fermion. We design strategies for detection of this nonlocality by using the phenomenon of Coulomb-mediated Majorana coupling in a setting which still
Improved lower bounds for the atomic charge density at the nucleus
Energy Technology Data Exchange (ETDEWEB)
Galvez, F.J.; Porras, I.; Angulo, J.C.; Dehesa, J.S.
1988-06-14
Lower bounds F(..cap alpha.., ..beta..) for the electronic charge density of atomic systems with N electrons at the nucleus, p (O), are given by means of any two radial expectation values
Efimov states in asymmetric three-body atomic clusters
Kolganova, E. A.
2017-11-01
The work is devoted to the investigation of the weakly bound three-body atomic clusters. The calculations on the van der Waals trimer 7Li4He2 are carried out using the differential Faddeev equations, which allows us to give accurate binding energies for both the ground and the exited state of the system. The results obtained indicate the Efimov nature of the excited state in this system.
Mass spectrum bound state systems with relativistic corrections
Energy Technology Data Exchange (ETDEWEB)
Dineykhan, M; Zhaugasheva, S A [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Toinbaeva, N Sh; Jakhanshir, A [al-Farabi Kazak National University, 480012 Almaty (Kazakhstan)
2009-07-28
Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including relativistic corrections. The mass spectrum of the bound state is analytically derived. The mechanism for arising of the constituent mass of the relativistic bound-state forming particles is explained. The mass and the constituent mass of the two-, three- and n-body relativistic bound states are calculated taking into account relativistic corrections. The corrections arising due to the one- and two-loop electron polarization to the energy spectrum of muonic hydrogen with orbital and radial excitations are calculated.
Bound states in Galilean-invariant quantum field theory
Energy Technology Data Exchange (ETDEWEB)
Corley, S.R.; Greenberg, O.W. [Center for Theoretical Physics, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)
1997-02-01
We consider the nonrelativistic quantum mechanics of a model of two spinless fermions interacting via a two-body potential. We introduce quantum fields associated with the two particles as well as the expansion of these fields in asymptotic {open_quotes}in{close_quotes} and {open_quotes}out{close_quotes} fields, including such fields for bound states, in principle. We limit our explicit discussion to a two-body bound state. In this context we discuss the implications of the Galilean invariance of the model and, in particular, show how to include bound states in a strictly Galilean-invariant quantum field theory. {copyright} {ital 1997 American Institute of Physics.}
Dynamics Resonances in Atomic States of Astrophysical Relevance
Arefieff, K N; Bezuglov, N N; Dimitrijevic, M S; Klyucharev, A N; Mihajlov, A A; Sreckovic, V A
2016-01-01
Ionized geocosmic media parameters in a thermal and a subthermal range of energy have a number of unique features. The photoresonance plasma that is formed by optical excitation of the lowest excited (resonance) atomic states is one example of conversion of radiation energy into electrical one. Since spontaneous fluorescence of excited atoms is probabilistic, the description of the radiating quantized system evolution along with photons energy transfer in a cold atoms medium, should include elements of stochastic dynamics. Finally, the chaotic dynamics of a weakly bound Rydberg electron over a grid of the energy levels diagram of a quasi-molecular Rydberg complex provides an excitation migration of the electron forward to the ionization continuum. This work aims at discussing the specific features of the dynamic resonances formalism in the description of processes involving Rydberg states of an excited atom, including features in the fluorescence spectrum partially caused by the quantum defect control due to ...
Asymptotics of Rydberg states for the hydrogen atom
Energy Technology Data Exchange (ETDEWEB)
Thomas, L.E. [Virginia Univ., Charlottesville, VA (United States). Dept. of Mathematics; Villegas-Blas, C. [Universidad Nacional Autonoma de Mexico, Instituto de Matematicas, Unidad Cuernavaca, A. P. 273-3 Admon. 3, Cuernavaca Morelos 62251 (Mexico)
1997-08-01
The asymptotics of Rydberg states, i.e., highly excited bound states of the hydrogen atom Hamiltonian, and various expectations involving these states are investigated. We show that suitable linear combinations of these states, appropriately rescaled and regarded as functions either in momentum space or configuration space, are highly concentrated on classical momentum space or configuration space Kepler orbits respectively, for large quantum numbers. Expectations of momentum space or configuration space functions with respect to these states are related to time-averages of these functions over Kepler orbits. (orig.)
Search for Deeply Bound Kaonic Nuclear States with AMADEUS
Directory of Open Access Journals (Sweden)
Skurzok Magdalena
2017-01-01
Full Text Available We briefly report on the search for Deeply Bound Kaonic Nuclear States with AMADEUS in the Σ0p channel following K− absorption on 12C and outline future perspectives for this work.
New bounds for the atomic charge and momentum densities at the origin
Energy Technology Data Exchange (ETDEWEB)
Angulo, J.C.; Dehesa, J.S.; Galvez, F.J. (Granada Univ. (Spain). Dept. de Fisica Moderna)
1991-02-01
The 'Stieltjes moment problem' technique together with the positivity and monotonic decreasing properties of the electronic density of an atom is used to find new and more accurate lower bounds for the charge density at the nucleus and the momentum density at the origin, in terms of radial and momentum expectation values, respectively. Bounds depending on two and three expectation values are given explicitly and a Hartree-Fock study of their quality is carried out. Also, the behavior of the new bounds at large Z's is discussed. The Stieltjes technique allows to find lower bounds of better accuracy by including expectation values of higher order. (orig.).
Engineering quantum hyperentangled states in atomic systems
Nawaz, Mehwish; -Islam, Rameez-ul; Abbas, Tasawar; Ikram, Manzoor
2017-11-01
Hyperentangled states have boosted many quantum informatics tasks tremendously due to their high information content per quantum entity. Until now, however, the engineering and manipulation of such states were limited to photonic systems only. In present article, we propose generating atomic hyperentanglement involving atomic internal states as well as atomic external momenta states. Hypersuperposition, hyperentangled cluster, Bell and Greenberger–Horne–Zeilinger states are engineered deterministically through resonant and off-resonant Bragg diffraction of neutral two-level atoms. Based on the characteristic parameters of the atomic Bragg diffraction, such as comparatively large interaction times and spatially well-separated outputs, such decoherence resistant states are expected to exhibit good overall fidelities and offer the evident benefits of full controllability, along with extremely high detection efficiency, over the counterpart photonic states comprised entirely of flying qubits.
Anisotropy-induced photonic bound states in the continuum
Gomis-Bresco, Jordi; Artigas, David; Torner, Lluis
2017-03-01
Bound states in the continuum (BICs) are radiationless localized states embedded in the part of the parameter space that otherwise corresponds to radiative modes. Many decades after their original prediction and early observations in acoustic systems, such states have been demonstrated recently in photonic structures with engineered geometries. Here, we put forward a mechanism, based on waveguiding structures that contain anisotropic birefringent materials, that affords the existence of BICs with fundamentally new properties. In particular, anisotropy-induced BICs may exist in symmetric as well as in asymmetric geometries; they may form in tunable angular propagation directions; their polarization may be pure transverse electric, pure transverse magnetic or full vector with tunable polarization hybridity; and they may be the only possible bound states of properly designed structures, and thus appear as a discrete, isolated bound state embedded in a whole sea of radiative states.
Trapping cold ground state argon atoms.
Edmunds, P D; Barker, P F
2014-10-31
We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39) C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10) cm(3) s(-1).
Observation of the continuous stern-gerlach effect on an electron bound in an atomic Ion
Hermanspahn; Haffner; Kluge; Quint; Stahl; Verdu; Werth
2000-01-17
We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus.
Computed bound and continuum electronic states of the nitrogen molecule
Directory of Open Access Journals (Sweden)
Tennyson Jonathan
2015-01-01
Full Text Available The dissociative recombination (DR of N2+ is important for processes occurring in our atmosphere. However, it is not particularly well characterised, experimentally for the vibrational ground state and, theoretically for the v ≥ 4. We use the R-matrix method to compute potential energy curves for both the bound Rydberg states of nitrogen and for quasi-bound states lying in the continuum. Use of a fine mesh of internuclear separations allows the details of avoided crossings to be determined. The prospects for using the curves as the input for DR calculations is discussed.
The generalized pseudospectral approach to the bound states of the ...
Indian Academy of Sciences (India)
Abstract. The generalized pseudospectral (GPS) method is employed to calculate the bound states of the Hulthén and the Yukawa potentials in quantum mechanics, with special emphasis on higher excited states and stronger couplings. Accurate energy eigenvalues, expectation values and radial probability densities are ...
Universal three-body bound states in mixed dimensions beyond the Efimov paradigm
Zhang, Pengfei; Yu, Zhenhua
2017-09-01
The Efimov effect was first predicted for three particles interacting at an s -wave resonance in three dimensions. A subsequent study showed that the same effect can be realized by considering two-body and three-body interactions in mixed dimensions. In this work, we consider the three-body problem of two bosonic A atoms interacting with another single B atom in mixed dimensions: The A atoms are confined in a space of dimension dA and the B atom in a space of dimension dB, and there is an interspecies s -wave interaction in a dint-codimensional space accessible to both species. We find that when the s -wave interaction is tuned on resonance, there emerge an infinite series of universal three-body bound states for {dA,dB,dint} ={2 ,2 ,0 } and {2 ,3 ,1 } . Going beyond the Efimov paradigm, the binding energies of these states follow the scaling ln| En|˜-s(n π -θ ) 2/4 , with the scaling factor s being unity for the former case and √{mB(2 mA+mB) }/(mA+mB) for the latter. We discuss the possibility of realizing our mixed-dimensional systems in a cold-atom experiment and how the effects of these universal three-body bound states may be detected.
Dancing Volvox: Hydrodynamic Bound States of Swimming Algae
Drescher, Knut; Leptos, Kyriacos C.; Tuval, Idan; Ishikawa, Takuji; Pedley, Timothy J.; Goldstein, Raymond E.
2013-01-01
The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox colonies swim close to a solid surface, they attract one another and can form stable bound states in which they “waltz” or “minuet” around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability, and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces. PMID:19518757
Bound on local unambiguous discrimination between multipartite quantum states
Yang, Ying-Hui; Gao, Fei; Tian, Guo-Jing; Cao, Tian-Qing; Zuo, Hui-Juan; Wen, Qiao-Yan
2015-02-01
We investigate the upper bound on unambiguous discrimination by local operations and classical communication. We demonstrate that any set of linearly independent multipartite pure quantum states can be locally unambiguously discriminated if the number of states in the set is no more than , where the space spanned by the set can be expressed in the irreducible form and is the optimal local dimension of the party. That is, is an upper bound. We also show that it is tight, namely there exists a set of states, in which at least one of the states cannot be locally unambiguously discriminated. Our result gives the reason why the multiqubit system is the only exception when any three quantum states are locally unambiguously distinguished.
Stieltjes electrostatic model interpretation for bound state problems
Indian Academy of Sciences (India)
In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges i ℏ , which are placed in between the two fixed imaginary charges arising due to the classical turning ...
A quantum bound-state description of black holes
Energy Technology Data Exchange (ETDEWEB)
Hofmann, Stefan [Arnold Sommerfeld Center for Theoretical Physics, LMU-München, Theresienstrasse 37, 80333 München (Germany); Rug, Tehseen, E-mail: Tehseen.Rug@physik.uni-muenchen.de [Arnold Sommerfeld Center for Theoretical Physics, LMU-München, Theresienstrasse 37, 80333 München (Germany); Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany)
2016-01-15
A relativistic framework for the description of bound states consisting of a large number of quantum constituents is presented, and applied to black-hole interiors. At the parton level, the constituent distribution, number and energy density inside black holes are calculated, and gauge corrections are discussed. A simple scaling relation between the black-hole mass and constituent number is established.
Scaling properties of net information measures for bound states of ...
Indian Academy of Sciences (India)
Using dimensional analyses, the scaling properties of the Heisenberg uncertainty relationship as well as the various information theoretical uncertainty-like relationships are derived for the bound states corresponding to the superposition of the power potential of the form () = + $^{n_{i}}, where , , , ...
Towards flavored bound states beyond rainbows and ladders
Energy Technology Data Exchange (ETDEWEB)
El-Bennich, B.; Rojas, E.; Melo, J. P. B. C. de [Laboratório de Física Teórica e Computacional, Universidade Cruzeiro do Sul, São Paulo 01506-000 SP (Brazil); Paracha, M. A. [Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul, Sao Paulo 01506-000 SP, Brazil and Centre for Advanced Mathematics and Physics, National University of Science and Technology, Islamabad (Pakistan)
2014-11-11
We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.
Higgs interchange and bound states of superheavy fermions
Indian Academy of Sciences (India)
Their dynamical production mechanisms are also considered. In §2.3 the existing theoretical models for 4G bound states are discussed. In §2.4 the general aspects of the present model are introduced. In §3 the dynamical model of the present work is discussed in detail. In particular, in. §3.1 the relativistic kinetic energy ...
Hartree–Fock variational bounds for ground state energy of ...
Indian Academy of Sciences (India)
The existence of a stable equilibrium high density ferromagnetic state with spheroidal occupation function is possible as long as the ratio of coupling constants Γcm ≡ (U0a3/μ2) is not very small compared to 1. Keywords. Chargeless fermions; magnetic dipole–dipole interaction; Hartree–Fock bounds; ferromagnetic ground ...
Hartree–Fock variational bounds for ground state energy of ...
Indian Academy of Sciences (India)
We use different determinantal Hartree–Fock (HF) wave functions to calculate true variational upper bounds for the ground state energy of spin-half fermions in volume 0, with mass , electric charge zero, and magnetic moment , interacting through magnetic dipole–dipole interaction. We ﬁnd that at high densities ...
Chiral Symmetry, Heavy Quark Symmetry and Bound States
Yoshida, Yuhsuke
1995-01-01
I investigate the bound state problems of lowest-lying mesons and heavy mesons. Chiral symmetry is essential when one consider lowest-lying mesons. Heavy quark symmetry plays an central role in considering the semi-leptonic form factors of heavy mesons. Various properties based on the symmetries are revealed using Bethe-Salpeter equations.
Programmable solid state atom sources for nanofabrication
Han, Han; Imboden, Matthias; Stark, Thomas; Del Corro, Pablo G.; Pardo, Flavio; Bolle, Cristian A.; Lally, Richard W.; Bishop, David J.
2015-06-01
In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ~1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques.In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ~1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques. Electronic supplementary information (ESI) available: A document containing further information about device characterization
Spectrum of Andreev bound states in Josephson junctions with a ferromagnetic insulator
Energy Technology Data Exchange (ETDEWEB)
Kawabata, Shiro, E-mail: s-kawabata@aist.go.jp [Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012 (Japan); Tanaka, Yukio [Department of Applied Physics, Nagoya University, Nagoya 464-8603 (Japan); Golubov, Alexander A. [Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Vasenko, Andrey S. [Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble (France); Asano, Yasuhiro [Department of Applied Physics, Hokkaido University, Sapporo 060-8628 (Japan)
2012-10-15
Ferromagnetic-insulator (FI) based Josephson junctions are promising candidates for a coherent superconducting quantum bit as well as a classical superconducting logic circuit. Recently the appearance of an intriguing atomic-scale 0-{pi} transition has been theoretically predicted. In order to uncover the mechanism of this phenomena, we numerically calculate the spectrum of Andreev bound states in a FI barrier by diagonalizing the Bogoliubov-de Gennes equation. We show that Andreev spectrum drastically depends on the parity of the FI-layer number L and accordingly the {pi}(0) state is always more stable than the 0 ({pi}) state if L is odd (even).
Bound Electron States in Skew-symmetric Quantum Wire Intersections
2014-01-01
for electronic transport studies was to confine resonant- tunneling heterostructures laterally with a fabrication-imposed po- tential. This approach...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Quantum Wires, Crossed Nanowires , Trapped Electron States, Quantum Dots REPORT...realistic systems such as semiconductor nanowire films and carbon nanotube bundles. Bound electron states in skew-symmetric quantum wire intersections by
Extending Quantum Chemistry of Bound States to Electronic Resonances
Jagau, Thomas-C.; Bravaya, Ksenia B.; Krylov, Anna I.
2017-05-01
Electronic resonances are metastable states with finite lifetime embedded in the ionization or detachment continuum. They are ubiquitous in chemistry, physics, and biology. Resonances play a central role in processes as diverse as DNA radiolysis, plasmonic catalysis, and attosecond spectroscopy. This review describes novel equation-of-motion coupled-cluster (EOM-CC) methods designed to treat resonances and bound states on an equal footing. Built on complex-variable techniques such as complex scaling and complex absorbing potentials that allow resonances to be associated with a single eigenstate of the molecular Hamiltonian rather than several continuum eigenstates, these methods extend electronic-structure tools developed for bound states to electronic resonances. Selected examples emphasize the formal advantages as well as the numerical accuracy of EOM-CC in the treatment of electronic resonances. Connections to experimental observables such as spectra and cross sections, as well as practical aspects of implementing complex-valued approaches, are also discussed.
Equation of state and self-bound droplet in Rabi-coupled Bose mixtures.
Cappellaro, Alberto; Macrì, Tommaso; Bertacco, Giovanni F; Salasnich, Luca
2017-10-17
Laser induced transitions between internal states of atoms have been playing a fundamental role to manipulate atomic clouds for many decades. In absence of interactions each atom behaves independently and their coherent quantum dynamics is described by the Rabi model. Since the experimental observation of Bose condensation in dilute gases, static and dynamical properties of multicomponent quantum gases have been extensively investigated. Moreover, at very low temperatures quantum fluctuations crucially affect the equation of state of many-body systems. Here we study the effects of quantum fluctuations on a Rabi-coupled two-component Bose gas of interacting alkali atoms. The divergent zero-point energy of gapless and gapped elementary excitations of the uniform system is properly regularized obtaining a meaningful analytical expression for the beyond-mean-field equation of state. In the case of attractive inter-particle interaction we show that the quantum pressure arising from Gaussian fluctuations can prevent the collapse of the mixture with the creation of a self-bound droplet. We characterize the droplet phase and discover an energetic instability above a critical Rabi frequency provoking the evaporation of the droplet. Finally, we suggest an experiment to observe such quantum droplets using Rabi-coupled internal states of K 39 atoms.
Quantum state engineering with single atom laser
Stefanov, V. P.
2017-11-01
On the basis of quantum stochastic trajectories approach it is shown that a single atom laser with coherent pumping can generate not only coherent states, but squeezed and Fock states, when different schemes of detection are followed by coherent feedback pulses or feedforward actions.
Entangled state fusion with Rydberg atoms
Ji, Y. Q.; Dai, C. M.; Shao, X. Q.; Yi, X. X.
2017-10-01
We propose a scheme for preparation of large-scale entangled GHZ states and W states with neutral Rydberg atoms. The scheme mainly depends on Rydberg antiblockade effect, i.e., as the Rydberg-Rydberg interaction strength and the detuning between the atom transition frequency and the classical laser frequency satisfies some certain conditions, the effective Rabi oscillation between the two ground states and the two excitation Rydberg states would be generated. The prominent advantage is that both two multiparticle GHZ states and two multiparticle W states can be fused in this model, especially the success probability for fusion of GHZ states can reach unit. In addition, the imperfections induced by the spontaneous emission is also discussed through numerical simulation.
Bound state densities and the Helmholtz free energy
Directory of Open Access Journals (Sweden)
Souza S.R.
2012-02-01
Full Text Available Bohr's conception of the compound nucleus is based on the idea of ‘longlived’ nuclear states in which all single particles are bound. We briefly discuss the properties of the density of bound states and then use two prescriptions, that of Brack and Quentin and that of Bonche, Levit e Vautherin to calculate the equivalent temperaturedependent quantity – the Helmholtz free energy.We compare the temperature dependence of the latter, as well as that of the excitation energy and entropy, obtained using the two prescriptions in self-consistent calculations within the relativistic Hartree and Skyrme models. We then discuss the extended, temperature-dependent liquid-drop approximation to the excitation and free energies obtained from fits to the self-consistent calculations over a wide range of charge and mass numbers.
Observation of Andreev bound states at spin-active interfaces
Energy Technology Data Exchange (ETDEWEB)
Beckmann, Detlef; Wolf, Michael Johannes [KIT, Institut fuer Nanotechnologie (Germany); Huebler, Florian [KIT, Institut fuer Nanotechnologie (Germany); KIT, Institut fuer Festkoerperphysik (Germany); Loehneysen, Hilbert von [KIT, Institut fuer Festkoerperphysik (Germany); KIT, Physikalisches Institut (Germany)
2013-07-01
We report on high-resolution differential conductance experiments on nanoscale superconductor/ferromagnet tunnel junctions with ultra-thin oxide tunnel barriers. We observe subgap conductance features which are symmetric with respect to bias, and shift according to the Zeeman energy with an applied magnetic field. These features can be explained by resonant transport via Andreev bound states induced by spin-active scattering at the interface. From the energy and the Zeeman shift of the bound states, both the magnitude and sign of the spin-dependent interfacial phase shifts between spin-up and spin-down electrons can be determined. These results contribute to the microscopic insight into the triplet proximity effect at spin-active interfaces.
Bound state equation for the Nakanishi weight function
Directory of Open Access Journals (Sweden)
J. Carbonell
2017-06-01
Full Text Available The bound state Bethe–Salpeter amplitude was expressed by Nakanishi using a two-dimensional integral representation, in terms of a smooth weight function g, which carries the detailed dynamical information. A similar, but one-dimensional, integral representation can be obtained for the Light-Front wave function in terms of the same weight function g. By using the generalized Stieltjes transform, we first obtain g in terms of the Light-Front wave function in the complex plane of its arguments. Next, a new integral equation for the Nakanishi weight function g is derived for a bound state case. It has the standard form g=Ng, where N is a two-dimensional integral operator. We give the prescription for obtaining the kernel N starting with the kernel K of the Bethe–Salpeter equation. The derivation is valid for any kernel given by an irreducible Feynman amplitude.
Bound States in the Continuum in Nuclear and Hadron Physics
Lenske, H; Cao, Xu
2015-01-01
The population of bound states in the continuum and their spectral properties are studied on the nuclear and hadronic scale. The theoretical approach is presented and realizations in nuclear and charmonium spectroscopy are dis- cussed. The universality of the underlying dynamical principles is pointed out. Applications to nuclear systems at the neutron dripline and for charmonium spectroscopy by $e^- e^+ \\to D\\bar{D}$ production are discussed.
A quantum bound-state description of black holes
Directory of Open Access Journals (Sweden)
Stefan Hofmann
2016-01-01
Full Text Available A relativistic framework for the description of bound states consisting of a large number of quantum constituents is presented, and applied to black-hole interiors. At the parton level, the constituent distribution, number and energy density inside black holes are calculated, and gauge corrections are discussed. A simple scaling relation between the black-hole mass and constituent number is established.
R-matrix calculations for few-quark bound states
Energy Technology Data Exchange (ETDEWEB)
Shalchi, M.A. [Instituto de Fisica Teorica, UNESP, Sao Paulo, SP (Brazil); Hadizadeh, M.R. [Ohio University, Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Athens, OH (United States); Central State University, College of Science and Engineering, Wilberforce, OH (United States)
2016-10-15
The R-matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark, and pentaquarks in configuration space, as the bound states of quark-antiquark, diquark-quark, diquark-antidiquark, and diquark-antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by other methods in momentum and configuration spaces and also by available experimental data. (orig.)
Bound states of the Dirac equation on Kerr spacetime
Dolan, Sam R
2015-01-01
We formulate the Dirac equation for a massive neutral spin-half particle on a rotating black hole spacetime, and we consider its (quasi)bound states: gravitationally-trapped modes which are regular across the future event horizon. These bound states decay with time, due to the absence of superradiance in the (single-particle) Dirac field. We introduce a practical method for computing the spectrum of energy levels and decay rates, and we compare our numerical results with known asymptotic results in the small-$M \\mu$ and large-$M \\mu$ regimes. By applying perturbation theory in a horizon-penetrating coordinate system, we compute the `fine structure' of the energy spectrum, and show good agreement with numerical results. We obtain data for a hyperfine splitting due to black hole rotation. We evolve generic initial data in the time domain, and show how Dirac bound states appear as spectral lines in the power spectra. In the rapidly-rotating regime, we find that the decay of low-frequency co-rotating modes is sup...
Bound-state formation in falling liquid films
Nguyen, Phuc-Khanh; Pradas, Marc; Kalliadasis, Serafim; Bontozoglou, Vasilis
2012-11-01
Direct numerical simulation shows that the interaction between solitary pulses may give rise to the formation of bound states consisting of two or more pulses separated by well-defined distances and traveling at the same velocity. Stationary pulse couples are studied first. The resulting equilibrium pulse distances compare favorably to theoretical predictions at large and intermediate pulse separations. When the two pulses are closely spaced, the theory becomes increasingly less accurate. Their time-dependent simulations indicate that all initial conditions of large separations lead to a monotonic attraction or repulsion to the stable bound states. However, intermediate range leads to a self-sustained oscillatory variation of the pulse separation distance, with well-defined amplitude and period, and a mean separation coinciding with the stationary distance. Eventually a very close separation causes an explosive repulsion of two pulses toward much larger stable separation. Bound states consisting of three pulses are computed next. The equilibrium separation distances in a symmetric system are similar to predictions based on simple couples. However, in an asymmetric one, they deviate significantly from simple predictions. Partially supported by FP7-Marie Curie ITN-``MULTIFLOW''-GA-214919-2.
From kaonic atoms to kaonic nuclei: A search for antikaon-mediated bound nuclear systems
Zmeskal, Johann
2008-10-01
Strong interaction processes were intensively studied at low energy with exotic atoms, touching one of the fundamental problems in hadron physic today - the still unsolved question of how hadron masses are generated. The question of the origin of the large hadron masses made up of light quarks, the current mass of the up ( u) and down ( d) quarks ( m≈5 MeV) is two orders of magnitude smaller than a typical hadron mass of about 1 GeV, will be discussed in the context with the experimental work done in the field of exotic atoms expanded to exotic nuclei. An overview of the properties of exotic hydrogen atoms made of pions and kaons are presented, using high precision experiments unrevealing the nature of strong interaction physics at low energy. A new field which contributes to the understanding of the origin of the large hadron mass is the study of the mass modification in a nuclear medium. Antikaon mediated bound nuclear systems would be an ideal tool, if they exist, to look for chiral restoration at high density and zero temperature or even more exotic to look for phase transitions.
A narrow quasi-bound state of the DNN system
Energy Technology Data Exchange (ETDEWEB)
Doté, A., E-mail: dote@post.kek.jp [KEK Theory Center, Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan); J-PARC Branch, KEK Theory Center, IPNS, KEK, 203-1, Shirakata, Tokai, Ibaraki, 319-1106 (Japan); Bayar, M. [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Department of Physics, Kocaeli University, 41380 Izmit (Turkey); Xiao, C.W. [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Hyodo, T. [Department of Physics, Tokyo Institute of Technology, Meguro, 152-8551 (Japan); Oka, M. [J-PARC Branch, KEK Theory Center, IPNS, KEK, 203-1, Shirakata, Tokai, Ibaraki, 319-1106 (Japan); Department of Physics, Tokyo Institute of Technology, Meguro, 152-8551 (Japan); Oset, E. [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Aptdo. 22085, 46071 Valencia (Spain)
2013-09-20
We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λ{sub c}(2595) is dynamically generated as a DN quasi-bound state, similarly to the Λ(1405) as a K{sup ¯}N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the DNN(J{sup π}=0{sup −},I=1/2) is found to be a narrow quasi-bound state below Λ{sub c}(2595)N threshold: total binding energy ∼225 MeV and mesonic decay width ∼25 MeV. On the other hand, the J{sup π}=1{sup −} state is considered to be a scattering state of Λ{sub c}(2595) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the DNN(J{sup π}=0{sup −},I=1/2) such that the D meson stays around the center of the total system due to the heaviness of the D meson.
Stationary bound states of Dirac particles in collapsar's fields
Gorbatenko, M. V.; Neznamov, V. P.
2012-03-01
For a Schwarzschild gravitational field by use of a self-conjugate Hamiltonian with a flat scalar product in a wide interval of gravitational constant stationary non-decaiing in time bound states for spin 1/2 elementary particles have been obtained for a first time. To obtain a discrete energies spectrum a boundary condition was introduced, corresponding to null current density of Dirac partciles near the events horizon. The results obtained could lead to reevaluation of some existing representations of the standart cosmological model, related with the Universe's evolution and with collapsars interactions with encountering media.
Quarkonium-nucleus bound states from lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Beane, S. R. [Univ. of Washington, Seattle, WA (United States); Chang, E. [Univ. of Washington, Seattle, WA (United States); Cohen, S. D. [Univ. of Washington, Seattle, WA (United States); Detmold, W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lin, H. -W. [Univ. of Washington, Seattle, WA (United States); Orginos, K. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Parreño, A. [Univ., de Barcelona, Marti Franques (Spain); Savage, M. J. [Univ. of Washington, Seattle, WA (United States)
2015-06-11
Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.
Bridge between bound state and reaction effective nucleon–nucleon ...
Indian Academy of Sciences (India)
Bridge between bound state and N–N potentials. Table 2. Parameters of the potential. v0 (MeV). 590. 432. 448. 495 c (fm). 1.34. 1.12. 1.03. 0.99 r0 (fm). 1.2. 1.2. 1.2. 1.2 σ (fm). 0.8. 1.0. 1.2. 1.4. BE (MeV). 128.4. 127.6. 127.5. 126.8. R (fm). 2.73. 2.73. 2.73. 2.73. It must be mentioned here that in our earlier detailed analysis ...
Resonantly Trapped Bound State in the Continuum Laser
Lepetit, Thomas; Kodigala, Ashok; Bahari, Babak; Fainman, Yeshaiahu; Kanté, Boubacar
2015-01-01
Cavities play a fundamental role in wave phenomena from quantum mechanics to electromagnetism and dictate the spatiotemporal physics of lasers. In general, they are constructed by closing all "doors" through which waves can escape. We report, at room temperature, a bound state in the continuum laser that harnesses optical modes residing in the radiation continuum but nonetheless may possess arbitrarily high quality factors. These counterintuitive cavities are based on resonantly trapped symmetry-compatible modes that destructively interfere. Our experimental demonstration opens exciting avenues towards coherent sources with intriguing topological properties for optical trapping, biological imaging, and quantum communication.
Relation between properties of long-range diatomic bound states
DEFF Research Database (Denmark)
Spirko, Vladimir; Sauer, Stephan P. A.; Szalewicz, Krzysztof
2013-01-01
Long-range states of diatomic molecules have average values of internuclear separations at least one order of magnitude larger than the equilibrium value of R. For example, the helium dimer 4He2 has a single bound state with of about 50 Å. We show that the properties of these states, such as ...>, the dissociation energy, or the s-wave scattering length, can be related by simple, yet very accurate formulas if a potential energy curve is known. By examining a range of ab initio and empirical helium dimer potentials, as well as scaling these potentials, we found that the formulas remain accurate even if very...
Helical liquids and Majorana bound states in quantum wires.
Oreg, Yuval; Refael, Gil; von Oppen, Felix
2010-10-22
We show that the combination of spin-orbit coupling with a Zeeman field or strong interactions may lead to the formation of a helical electron liquid in single-channel quantum wires, with spin and velocity perfectly correlated. We argue that zero-energy Majorana bound states are formed in various situations when such wires are situated in proximity to a conventional s-wave superconductor. This occurs when the external magnetic field, the superconducting gap, or, most simply, the chemical potential vary along the wire. These Majorana states do not require the presence of a vortex in the system. Experimental consequences of the helical liquid and the Majorana states are also discussed.
Energy Technology Data Exchange (ETDEWEB)
Requardt, M.
1985-01-01
For a large class of potentials the author proves upper bounds on the number of bound states in the various angular momentum channels below a certain energy E. As by-product he derives estimates on the maximal angular momentum etc. The class of allowed potentials enclose as typical candidate potentials with infinitely many bound states below the essential spectrum, respectively potentials which go to infinity for r ..-->.. infinity as e.g. the model potentials used in quarkonium physics like V(r) = -a(1/r) + br. Generalizations to the case of N-body quantum mechanics seem to be possible. (Auth.).
In-medium bound states and pairing gap
Rubtsova, O. A.; Kukulin, V. I.; Pomerantsev, V. N.; Müther, H.
2017-09-01
The two-particle Green's function and T matrix including pphh correlations in infinite nuclear matter are evaluated by a diagonalization of the effective total Hamiltonian. This diagonalization procedure corresponds to the same eigenvalue problem as for the pphh Random Phase Approximation. The effective Hamiltonian is nonHermitian and, for specific density domains and partial waves, yields pairs of complex conjugated eigenvalues and eigenfunctions representing in-medium bound states of two nucleons. The occurrence of these complex poles of the two-particle in-medium Green's function indicates the well known pairing instability. It is shown that the corresponding bound-state wave functions contain momentum dependencies of the BCS gap function, so that the latter can be found from a single diagonalization procedure for the effective Hamiltonian matrix. The approach is illustrated by calculations for S10 and 2 3P F gap functions in neutron matter which essentially coincide with the results found by a direct solving of the BCS gap equation. However the developed approach shows a new interesting feature, i.e., the gap closure and a phase transition point at very low density in the case of coupled channels 1 3S D in symmetric nuclear matter. This finding goes beyond the conventional BCS treatment and is discussed in the context of transition from Bose-Einstein condensation of quasideuterons to the formation of BCS pairing.
N2(+) bound quartet and sextet state potential energy curves
Partridge, H.; Bauschlicher, C. W., Jr.; Stallcop, J. R.
1985-01-01
The N2(+) potential energies have been determined from a complete active space self-consistent field calculation with active 2s and 2p electrons. A (6s 4p 3d 1f) Gaussian basis set was used together with additional higher angular momentum and diffuse functions. The calculated potential energy curves for the states 4Sigma(mu)(+), 4Pi(g), and 6Sigma(g)(+), for which there are no spectroscopic observations, are presented. The corresponding spectroscopic constants have been determined from a polynomial curve fit to the computed energies near the well minima and are shown. The 6Sigma(g)(+) state is found to be significantly bound, with a minimum at 1.72 A.
Non-destructive state measurement of individual neutral atoms
Gibbons, Michael; Shih, Chung-Yu; Hamley, Chris; Chapman, Michael
2011-05-01
Non-destructive state detection of individual neutral atoms is essential for scalable neutral atom quantum information processing. We have demonstrated non-destructive fluorescent state detection of individual neutral atom qubits trapped in an optical lattice. The hyperfine state of the atom is measured with 95% accuracy and the atom loss rate of 1%. State detection is performed on individual atoms over 100 times before being lost from the trap, representing a significant increase in the data collection rates. Using this technique, we have observed microwave Rabi oscillations with measurements done on one-and-the-same atom.
Dynamics Resonances in Atomic States of Astrophysical Relevance
Indian Academy of Sciences (India)
Since spontaneous fluorescence of excited atoms is probabilistic, the description of the radiating quantized system evolution along with photon energy transfer in a cold atom medium, should include elements of stochastic dynamics. Finally, the chaotic dynamics of a weakly bound Rydberg electron over a grid of the energy ...
Entanglement of two ground state neutral atoms using Rydberg blockade
DEFF Research Database (Denmark)
Miroshnychenko, Yevhen; Browaeys, Antoine; Evellin, Charles
2011-01-01
We report on our recent progress in trapping and manipulation of internal states of single neutral rubidium atoms in optical tweezers. We demonstrate the creation of an entangled state between two ground state atoms trapped in separate tweezers using the effect of Rydberg blockade. The quality...... of the entanglement is measured using global rotations of the internal states of both atoms....
Lasing action from photonic bound states in continuum
Kodigala, Ashok; Lepetit, Thomas; Gu, Qing; Bahari, Babak; Fainman, Yeshaiahu; Kanté, Boubacar
2017-01-01
In 1929, only three years after the advent of quantum mechanics, von Neumann and Wigner showed that Schrödinger’s equation can have bound states above the continuum threshold. These peculiar states, called bound states in the continuum (BICs), manifest themselves as resonances that do not decay. For several decades afterwards the idea lay dormant, regarded primarily as a mathematical curiosity. In 1977, Herrick and Stillinger revived interest in BICs when they suggested that BICs could be observed in semiconductor superlattices. BICs arise naturally from Feshbach’s quantum mechanical theory of resonances, as explained by Friedrich and Wintgen, and are thus more physical than initially realized. Recently, it was realized that BICs are intrinsically a wave phenomenon and are thus not restricted to the realm of quantum mechanics. They have since been shown to occur in many different fields of wave physics including acoustics, microwaves and nanophotonics. However, experimental observations of BICs have been limited to passive systems and the realization of BIC lasers has remained elusive. Here we report, at room temperature, lasing action from an optically pumped BIC cavity. Our results show that the lasing wavelength of the fabricated BIC cavities, each made of an array of cylindrical nanoresonators suspended in air, scales with the radii of the nanoresonators according to the theoretical prediction for the BIC mode. Moreover, lasing action from the designed BIC cavity persists even after scaling down the array to as few as 8-by-8 nanoresonators. BIC lasers open up new avenues in the study of light-matter interaction because they are intrinsically connected to topological charges and represent natural vector beam sources (that is, there are several possible beam shapes), which are highly sought after in the fields of optical trapping, biological sensing and quantum information.
Effect of substrate on optical bound states in the continuum in 1D photonic structures
DEFF Research Database (Denmark)
Sadrieva, Z. F.; Sinev, I. S.; Samusev, A. K.
2017-01-01
Optical bound states in the continuum (BIC) are localized states with energy lying above the light line and having infinite lifetime. Any losses taking place in real systems result in transformation of the bound states into resonant states with finite lifetime. In this work, we analyze properties...... into resonant states due to leakage into the diffraction channels opening in the substrate.......Optical bound states in the continuum (BIC) are localized states with energy lying above the light line and having infinite lifetime. Any losses taking place in real systems result in transformation of the bound states into resonant states with finite lifetime. In this work, we analyze properties...
Universal bounds on charged states in 2d CFT and 3d gravity
Energy Technology Data Exchange (ETDEWEB)
Benjamin, Nathan; Dyer, Ethan [Stanford Institute for Theoretical Physics, Via Pueblo, Stanford, CA, 94305 (United States); Fitzpatrick, A. Liam [Boston University Physics Department, Commonwealth Avenue, Boston, MA, 02215 (United States); Kachru, Shamit [Stanford Institute for Theoretical Physics, Via Pueblo, Stanford, CA, 94305 (United States)
2016-08-04
We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with c and provide examples that parametrically saturate this bound. We also prove that any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. We comment on the implications for charged states in three dimensional theories of gravity.
A simple model for atomic layer doped field-effect transistor (ALD-FET) electronic states
Energy Technology Data Exchange (ETDEWEB)
Mora R, M.E. [Centro de Investigaciones en Optica, Unidad Aguascalientes. Juan de Montoro 207, Zona Centro, 20000 Aguascalientes (Mexico); Gaggero S, L.M. [Escuela de Fisica, Universidad Autonoma de Zacatecas, Av. Preparatoria 301, 98060 Zacatecas (Mexico)
1998-12-31
We propose a simple potential model based on the Thomas-Fermi approximation to reproduce the main properties of the electronic structure of an atomic layer doped field effect transistor. Preliminary numerical results for a Si-based ALD-FET justify why bound electronic states are not observed in the experiment. (Author)
Quarkonium as a relativistic bound state on the light front
Li, Yang; Maris, Pieter; Vary, James P.
2017-07-01
We study charmonium and bottomonium as relativistic bound states in a light-front quantized Hamiltonian formalism. The effective Hamiltonian is based on light-front holography. We use a recently proposed longitudinal confinement to complete the soft-wall holographic potential for the heavy flavors. The spin structure is generated from the one-gluon exchange interaction with a running coupling. The adoption of asymptotic freedom improves the spectroscopy compared with previous light-front results. Within this model, we compute the mass spectroscopy, decay constants and the r.m.s. radii. We also present a detailed study of the obtained light-front wave functions and use the wave functions to compute the light-cone distributions, specifically the distribution amplitudes and parton distribution functions. Overall, our model provides a reasonable description of the heavy quarkonia.
Sarkar, Resham; Fang, Renpeng; Tu, Yanfei; Shahriar, Selim M
2014-01-01
We investigate the behavior of an ensemble of N non-interacting, identical atoms, excited by a laser with a wavelength of $\\lambda$. In general, the i-th atom sees a Rabi frequency $\\Omega_i$, an initial position dependent laser phase $\\phi_i$, and a motion induced Doppler shift of $\\delta_i$. When $\\Omega_i=\\Omega$ and $\\delta_i=\\delta$ for all atoms, the system evolves into a superposition of (N+1) symmetric collective states (SCS), independent of the values of $\\phi_i$. If $\\phi_i=\\phi$ for all atoms, these states simplify to the well-known Dicke collective states. When $\\Omega_i$ or $\\delta_i$ is distinct for each atom, the system evolves into a superposition of SCS as well as asymmetric collective states (ACS). For large N, the number of ACS's $(2^N-N-1)$ is far greater than that of the SCS. We show how to formulate the properties of all the collective states under various non-idealities, and use this formulation to understand the dynamics thereof. For the case where $\\Omega_i=\\Omega$ and $\\delta_i=\\delt...
Nondestructive fluorescent state detection of single neutral atom qubits.
Gibbons, Michael J; Hamley, Christopher D; Shih, Chung-Yu; Chapman, Michael S
2011-04-01
We demonstrate nondestructive (lossless) fluorescent state detection of individual neutral atom qubits trapped in an optical lattice. The hyperfine state of the atom is measured with a 95% accuracy and an atom loss rate of 1%. Individual atoms are initialized and detected over 100 times before being lost from the trap, representing a 100-fold improvement in data collection rates over previous experiments. Microwave Rabi oscillations are observed with repeated measurements of one and the same single atom. © 2011 American Physical Society
Probing the Dark Sector with Dark Matter Bound States.
An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue
2016-04-15
A model of the dark sector where O(few GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.
Bounds for entanglement of formation of two mode squeezed thermal states
Energy Technology Data Exchange (ETDEWEB)
Chen, Xiao-Yu; Qiu, Pei-Liang
2003-07-28
The upper and lower bounds of entanglement of formation are given for two mode squeezed thermal state. The bounds are compared with other entanglement measure or bounds. The entanglement distillation and the relative entropy of entanglement of infinitive squeezed state are obtained at the postulation of hashing inequality.
Theoretical study of the low-lying bound states of O2
Partridge, Harry; Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.
1991-01-01
It is demonstrated that a complete-active-space self-consistent-field (CASSCF) (2p)/MRCI + Q (multireference configuration interaction with a Davidson correction) description in a (13s8p6d 4f2g)/((5s4p3d 2f1g) atomic natural orbits (ANO) basis set supplemented with diffuse functions provides a quantitative description of the six lowest states of O2. The calculated potentials are within 0.05 eV (1.2 kilocal/mol) of accurate experimental results. The importance of substantially expanding the primitive basis set has been investigated, and it is demonstrated that such expansions yield insignificant improvement in the spectroscopic constants. Potential energy curves have also been reported for the weakly bound states of O2. The 5Pi(g) state is estimated to have a D(e) of 0.16 +/- 0.03 eV. The upper bound of D(e) is found to be sufficiently large that the importance of this state as a precursor for the formation of O2 (b 1Sigma(t)(+)) and O(1S) should be reconsidered.
Wallace, Rodrick
2015-08-01
The stabilization of human cognition via feedback from embedding social and cultural contexts is a dynamic process deeply intertwined with it, constituting, in a sense, the riverbanks directing the flow of a stream of generalized consciousness at different scales: Cultural norms and social interaction are synergistic with individual and group cognition and their disorders. A canonical failure mode in atomistic cultures is found to be a 'ground state' collapse well represented by atomistic models of economic interaction that are increasingly characterized as divorced from reality by heterodox economists. That is, high rates of psychopathic and antisocial personality disorder and obsessive compulsive disorder emerge as culture-bound syndromes particular to Western or Westernizing societies, or to those undergoing social disintegration.
Andreev bound states probed in three-terminal quantum dots
Gramich, J.; Baumgartner, A.; Schönenberger, C.
2017-11-01
Andreev bound states (ABSs) are well-defined many-body quantum states that emerge from the hybridization of individual quantum dot (QD) states with a superconductor and exhibit very rich and fundamental phenomena. We demonstrate several electron transport phenomena mediated by ABSs that form on three-terminal carbon nanotube (CNT) QDs, with one superconducting (S) contact in the center and two adjacent normal-metal (N) contacts. Three-terminal spectroscopy allows us to identify the coupling to the N contacts as the origin of the Andreev resonance (AR) linewidths and to determine the critical coupling strengths to S, for which a ground state (or quantum phase) transition in such S-QD systems can occur. In addition, we ascribe replicas of the lowest-energy ABS resonance to transitions between the ABS and odd-parity excited QD states, a process we call excited state ABS resonances. In the conductance between the two N contacts we find a characteristic pattern of positive and negative differential subgap conductance, which we explain by considering two nonlocal processes, the creation of Cooper pairs in S by electrons from both N terminals, and a transport mechanism we call resonant ABS tunneling, possible only in multiterminal QD devices. In the latter process, electrons are transferred via the ABS without effectively creating Cooper pairs in S. The three-terminal geometry also allows spectroscopy experiments with different boundary conditions, for example by leaving S floating. Surprisingly, we find that, depending on the boundary conditions and the device parameters, the experiments either show single-particle Coulomb blockade resonances, ABS characteristics, or both in the same measurements, seemingly contradicting the notion of ABSs replacing the single-particle states as eigenstates of the QD. We qualitatively explain these results as originating from the finite time scale required for the coherent oscillations between the superposition states after a single
Wu, Hai-Dan; Zhou, Tao
2017-11-01
We propose theoretically an effective scheme for braiding Majorana bound states by manipulating the point potential. The vortex pinning effect is carefully elucidated. This effect can be used to control the vortices and Majorana bound states in topological superconductors. The exchange of two vortices induced by moving the potentials is simulated numerically. The zero-energy state in the vortex core is robust with respect to the strength of the potential. The Majorana bound states in a pinned vortex are identified numerically.
Optical nonlinearities of excitonic states in atomically thin 2D transition metal dichalcogenides
Energy Technology Data Exchange (ETDEWEB)
Soh, Daniel Beom Soo [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Proliferation Signatures Discovery and Exploitation Department
2017-08-01
We calculated the optical nonlinearities of the atomically thin monolayer transition metal dichalcogenide material (particularly MoS_{2}), particularly for those linear and nonlinear transition processes that utilize the bound exciton states. We adopted the bound and the unbound exciton states as the basis for the Hilbert space, and derived all the dynamical density matrices that provides the induced current density, from which the nonlinear susceptibilities can be drawn order-by-order via perturbative calculations. We provide the nonlinear susceptibilities for the linear, the second-harmonic, the third-harmonic, and the kerr-type two-photon processes.
Generation and storage of quantum states using cold atoms
DEFF Research Database (Denmark)
Dantan, Aurelien Romain; Josse, Vincent; Cviklinski, Jean
2006-01-01
Cold cesium or rubidium atomic samples have a good potential both for generation and storage of nonclassical states of light. Generation of nonclassical states of light is possible through the high non-linearity of cold atomic samples excited close to a resonance line. Quadrature squeezing......, polarization squeezing and entanglement have been demonstrated. Quantum state storage is made possible by the presence of long-lived angular momentum in the ground state. Cold atoms are thus a promising resource in quantum information....
Majorana bound states in a coupled quantum-dot hybrid-nanowire system
DEFF Research Database (Denmark)
Deng, M. T.; Vaitiekenas, S.; Hansen, E. B.
2017-01-01
Hybrid nanowires combining semiconductor and superconductor materials appear well suited for the creation, detection, and control of Majorana bound states (MBSs). We demonstrate the emergence of MBSs from coalescing Andreev bound states (ABSs) in a hybrid InAs nanowire with epitaxial Al, using...... with the end-dot bound state, which is in agreement with a numerical model. The ABS/MBS spectra provide parameters that are useful for understanding topological superconductivity in this system....
Bound states and perfect transmission scattering states in P T -symmetric open quantum systems
Garmon, Savannah; Gianfreda, Mariagiovanna; Hatano, Naomichi
2014-03-01
We study the point spectrum and transmission scattering spectrum in P T -symmetric open quantum systems containing balanced regions of energy amplification and attenuation, using tight-binding chains with matching sink and source sites as prototype models. For a given system geometry, we write the boundary conditions that permit scattering state and bound state solutions with wave functions that likewise satisfy P T symmetry; we further demonstrate the P T -symmetric scattering states give rise to perfect transmission through the scattering region. We also discuss bound states in continuum and other spectral effects that may be discovered in P T -symmetric open quantum systems. Finally we discuss the potential for experimental realization of our models in systems containing whispering gallery mode resonators with balanced loss and gain. S. G. acknowledges support from the Japan Society for the Promotion of Science.
Glover, R. M.; Weinhold, F.
1977-01-01
Variational functionals of Braunn and Rebane (1972) for the imagery-frequency polarizability (IFP) have been generalized by the method of Gramian inequalities to give rigorous upper and lower bounds, valid even when the true (but unknown) unperturbed wavefunction must be represented by a variational approximation. Using these formulas in conjunction with flexible variational trial functions, tight error bounds are computed for the IFP and the associated two- and three-body van der Waals interaction constants of the ground 1(1S) and metastable 2(1,3S) states of He and Li(+). These bounds generally establish the ground-state properties to within a fraction of a per cent and metastable properties to within a few per cent, permitting a comparative assessment of competing theoretical methods at this level of accuracy. Unlike previous 'error bounds' for these properties, the present results have a completely a priori theoretical character, with no empirical input data.
Topological states in engineered atomic lattices
Drost, Robert; Ojanen, Teemu; Harju, Ari; Liljeroth, Peter
2017-07-01
Topological materials exhibit protected edge modes that have been proposed for applications in, for example, spintronics and quantum computation. Although a number of such systems exist, it would be desirable to be able to test theoretical proposals in an artificial system that allows precise control over the key parameters of the model. The essential physics of several topological systems can be captured by tight-binding models, which can also be implemented in artificial lattices. Here, we show that this method can be realized in a vacancy lattice in a chlorine monolayer on a Cu(100) surface. We use low-temperature scanning tunnelling microscopy (STM) to fabricate such lattices with atomic precision and probe the resulting local density of states (LDOS) with scanning tunnelling spectroscopy (STS). We create analogues of two tight-binding models of fundamental importance: the polyacetylene (dimer) chain with topological domain-wall states, and the Lieb lattice with a flat electron band. These results provide an important step forward in the ongoing effort to realize designer quantum materials with tailored properties.
On the bound state of the antiproton-deuterium-tritium ion
Frolov, Alexei M
2012-01-01
It is shown that the ground state in the Coulomb three-body $\\bar{p}dt$ ion is bound. This ion consists of the positevely charged deuterium $d$ and tritum $t$ nuclei and one negatively charged antirpoton $\\bar{p}$. The $\\bar{p}dt$ ion has only one bound $S(L = 0)-$state which is weakly-bound. The properties of this weakly-bound state are investigated with the use of the results of recent highly accurate computations. Very likely, the actual proparties of the $\\bar{p}dt$ ion will be different from the results of our predictions due to additional contributions from strong interactions between particles.
A study of the bound states for square potential wells with position-dependent mass
Energy Technology Data Exchange (ETDEWEB)
Ganguly, A. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: gangulyasish@rediffmail.com; Kuru, S. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: kuru@science.ankara.edu.tr; Negro, J. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: jnegro@fta.uva.es; Nieto, L.M. [Departamento de Fisica Teorica, Atomica y Optica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: luismi@metodos.fam.cie.uva.es
2006-12-25
A potential well with position-dependent mass is studied for bound states. Applying appropriate matching conditions, a transcendental equation is derived for the energy eigenvalues. Numerical results are presented graphically and the variation of the energy of the bound states are calculated as a function of the well-width and mass.
The bound state S-matrix for AdS5×S5 superstring
Arutyunov, G.E.; de Leeuw, M.; Torrielli, A.
2009-01-01
We determine the S-matrix that describes scattering of arbitrary bound states in the light-cone string theory in AdS5×S5. The corresponding construction relies on the Yangian symmetry and the superspace formalism for the bound state representations. The basic analytic structure supporting the
Stieltjes electrostatic model interpretation for bound state problems
Indian Academy of Sciences (India)
+ iQ(xk) = 0, 1 ≤ k ≤ n. (17) the solution for the differential eq. (17), for an exactly solvable potential that is for cer- tain Q(xk), are the zeros of appropriate orthogonal polynomials. The interval is fixed by the fixed poles of the potential. It is well known that the classical orthogonal poly- nomials arise as solutions to the bound ...
Controlling multipolar radiation with symmetries for electromagnetic bound states in the continuum
Lepetit, Thomas; Kanté, Boubacar
2014-12-01
Interferences in open systems embedded in a continuum can lead to states that are bound within the continuum itself. An electromagnetic state that naturally decays becomes bound at a unique point in phase space. We demonstrate the striking occurrence of multiple such peculiar states in coupled deep subwavelength resonators. The bound states in the continuum originate from the control of multipolar radiation and their symmetries. The architectures investigated here, using all-dielectric resonators, constitute a flexible and readily achievable platform for applications requiring strong light-matter interaction and light localization.
Energy Technology Data Exchange (ETDEWEB)
Wang,J.; Eldo, J.; Kantrowitz, E.
2007-01-01
The allosteric enzyme aspartate transcarbamoylase (ATCase) exists in two conformational states. The enzyme, in the absence of substrates is primarily in the low-activity T state, is converted to the high-activity R state upon substrate binding, and remains in the R state until substrates are exhausted. These conformational changes have made it difficult to obtain structural data on R-state active-site complexes. Here we report the R-state structure of ATCase with the substrate Asp and the substrate analog phosphonoactamide (PAM) bound. This R-state structure represents the stage in the catalytic mechanism immediately before the formation of the covalent bond between the nitrogen of the amino group of Asp and the carbonyl carbon of carbamoyl phosphate. The binding mode of the PAM is similar to the binding mode of the phosphonate moiety of N-(phosphonoacetyl)-l-aspartate (PALA), the carboxylates of Asp interact with the same residues that interact with the carboxylates of PALA, although the position and orientations are shifted. The amino group of Asp is 2.9 {angstrom} away from the carbonyl oxygen of PAM, positioned correctly for the nucleophilic attack. Arg105 and Leu267 in the catalytic chain interact with PAM and Asp and help to position the substrates correctly for catalysis. This structure fills a key gap in the structural determination of each of the steps in the catalytic cycle. By combining these data with previously determined structures we can now visualize the allosteric transition through detailed atomic motions that underlie the molecular mechanism.
Controlling the bound states in a quantum-dot hybrid nanowire
Ptok, Andrzej; Kobiałka, Aksel; Domański, Tadeusz
2017-11-01
Recent experiments using the quantum dot coupled to the topological superconducting nanowire [Deng et al., Science 354, 1557 (2016), 10.1126/science.aaf3961] revealed that the zero-energy bound state coalesces from the Andreev bound states. Such quasiparticle states, present in the quantum dot, can be controlled by magnetic and electrostatic means. We use a microscopic model of the quantum-dot-nanowire structure to reproduce the experimental results, applying the Bogoliubov-de Gennes technique. This is done by studying the gate voltage dependence of the various types of bound states and mutual influence between them. We show that the zero-energy bound states can emerge from the Andreev bound states in the topologically trivial phase and can be controlled using various means. In the nontrivial topological phase we show the possible resonance between these zero-energy levels with Majorana bound states. We discuss and explain this phenomenon as a result of dominant spin character of discussed bound states. Presented results can be applied in experimental studies by using the proposed nanodevice.
Versatile mode-locked fiber laser with switchable operation states of bound solitons.
Zou, Xin; Qiu, Jifang; Wang, Xiaodong; Ye, Zi; Shi, Jindan; Wu, Jian
2016-06-01
Bound states of two solitons are among the typical forms of bound states and can be observed in various operation states of mode-locked fiber lasers. We experimentally investigated bound solitons (BSs) in a passively mode-locked erbium-doped fiber laser based on a semiconductor saturable absorber mirror, whose operation states can be switched among multiple pulses, passively harmonic mode-locking, and "giant pulses" by simply adjusting the in-line polarization controller with the pump power fixed. Up to four pulses, fourth-order harmonic mode-locking (HML), and a "giant pulse" with four BSs were obtained with increasing pump power. Experimental results showed a correlative relationship among those operation states (N pulses/Nth-order HML/"giant pulses" of N bound solitons) at different pump power levels. The birefringence induced by the erbium-doped fiber inside the laser cavity played a vital role in the transitions of those operation states.
Dzyaloshinskii-Moriya interaction as an agent to free the bound entangled states
Sharma, Kapil K.; Pandey, S. N.
2016-04-01
In the present paper, we investigate the efficacy of Dzyaloshinskii-Moriya (DM) interaction to convert the bound entangled states into free entangled states. We consider the tripartite hybrid system as a pair of non interacting two qutrits initially prepared in bound entangled states and one auxiliary qubit. Here, we consider two types of bound entangled states investigated by Horodecki. The auxiliary qubit interacts with any one of the qutrit of the pair through DM interaction. We show that by tuning the probability amplitude of auxiliary qubit and DM interaction strength, one can free the bound entangled states, which can be further distilled. We use the reduction criterion to find the range of the parameters of probability amplitude of auxiliary qubit and DM interaction strength, for which the states are distillable. The realignment criterion and negativity have been used for detection and quantification of entanglement.
Accidental bound states in the continuum in an open Sinai billiard
Energy Technology Data Exchange (ETDEWEB)
Pilipchuk, A.S. [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660080 Krasnoyarsk (Russian Federation); Sadreev, A.F., E-mail: almas@tnp.krasn.ru [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation)
2017-02-19
The fundamental mechanism of the bound states in the continuum is the full destructive interference of two resonances when two eigenlevels of the closed system are crossing. There is, however, a wide class of quantum chaotic systems which display only avoided crossings of eigenlevels. As an example of such a system we consider the Sinai billiard coupled with two semi-infinite waveguides. We show that notwithstanding the absence of degeneracy bound states in the continuum occur due to accidental decoupling of the eigenstates of the billiard from the waveguides. - Highlights: • Bound states in the continuum in open chaotic billiards occur to accidental vanishing of coupling of eigenstate of billiard with waveguides.
Transport signatures of top-gate bound states with strong Rashba-Zeeman effect
Tang, Chi-Shung; Yu, Yun-Hsuan; Abdullah, Nzar Rauf; Gudmundsson, Vidar
2017-12-01
We suggest a single-mode spin injection scheme in non-ferromagnetic quantum channels utilizing perpendicular strong Rashba spin-orbit and Zeeman fields. By applying a positive top-gate potential in order to inject electrons from the spin-orbit gap to the low-energy regime, we observe coherent destruction of transport signatures of a hole-like quasi-bound state, an electron-like quasi-bound state, or a hole-like bound state features that are sensitive to the selection of the top-gate length along the transport direction.
Manipulating collective quantum states of ultracold atoms by probing
DEFF Research Database (Denmark)
Wade, Andrew Christopher James
2015-01-01
nature of the measurement interaction and backaction is yet to be realised. This dissertation is concerned with ultracold atoms and their control via fully quantum mechanical probes. Nonclassical, squeezed and entangled states of matter and single photon sources are important for fundamental studies...... and quantum technologies. By probing, the production of squeezed and entangled states of collective variables in a Bose-Einstein condensate is investigated. Thereafter, an atomic probe using the strong interactions between highly excited atomic states, manipulates the light-matter dynamics of an ultracold gas...
Generation of Exotic Quantum States of a Cold Atomic Ensemble
DEFF Research Database (Denmark)
Christensen, Stefan Lund
Over the last decades quantum effects have become more and more controllable, leading to the implementations of various quantum information protocols. These protocols are all based on utilizing quantum correlation. In this thesis we consider how states of an atomic ensemble with such correlations...... can be created and characterized. First we consider a spin-squeezed state. This state is generated by performing quantum non-demolition measurements of the atomic population difference. We show a spectroscopically relevant noise reduction of -1.7dB, the ensemble is in a many-body entangled state...... — a nanofiber based light-atom interface. Using a dual-frequency probing method we measure and prepare an ensemble with a sub-Poissonian atom number distribution. This is a first step towards the implementation of more exotic quantum states....
Atomic quantum superposition state generation via optical probing
DEFF Research Database (Denmark)
Nielsen, Anne Ersbak Bang; Poulsen, Uffe Vestergaard; Negretti, Antonio
2009-01-01
We analyze the performance of a protocol to prepare an atomic ensemble in a superposition of two macroscopically distinguishable states. The protocol relies on conditional measurements performed on a light field, which interacts with the atoms inside an optical cavity prior to detection, and we...
Bicudo, P.; Cardoso, M.
2016-11-01
We address q q Q ¯Q ¯ exotic tetraquark bound states and resonances with a fully unitarized and microscopic quark model. We propose a triple string flip-flop potential, inspired by lattice QCD tetraquark static potentials and flux tubes, combining meson-meson and double Y potentials. Our model includes the color excited potential, but neglects the spin-tensor potentials, as well as all the other relativistic effects. To search for bound states and resonances, we first solve the two-body mesonic problem. Then we develop fully unitary techniques to address the four-body tetraquark problem. We fold the four-body Schrödinger equation with the mesonic wave functions, transforming it into a two-body meson-meson problem with nonlocal potentials. We find bound states for some quark masses, including the one reported in lattice QCD. Moreover, we also find resonances and calculate their masses and widths, by computing the T matrix and finding its pole positions in the complex energy plane, for some quantum numbers. However, a detailed analysis of the quantum numbers where binding exists shows a discrepancy with recent lattice QCD results for the l l b ¯ b ¯ tetraquark bound states. We conclude that the string flip-flop models need further improvement.
Disorder-induced bound states within an adatom-quantum wire system
Magnetta, Bradley; Ordonez, Gonzalo
2014-03-01
Bound states induced by disorder are theoretically observed within a quantum wire and adatom system. The quantum wire is modeled as an array of quantum wells with random energies and exhibits Anderson Localization. By varying the energy of our adatom and adjusting the tunneling strength between the adatom and the quantum wire we observe disorder-induced bound states between the the adatom and its attached point. The characteristics of these disorder-induced bound states are greatly influenced by the site of interest on the quantum wire. Utilizing random quantum wires and disordered superlattices to produce bound states may offer flexibility in fabrication as well as provide grounds for energy transmission in photovoltaics.
Ultrasensitive optical absorption in graphene based on bound states in the continuum
National Research Council Canada - National Science Library
Zhang, Mingda; Zhang, Xiangdong
2015-01-01
We have designed a sphere-graphene-slab structure so that the electromagnetic wave can be well confined in the graphene due to the formation of a bound state in a continuum (BIC) of radiation modes...
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs.......Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs....
Quark-antiquark bound-state spectroscopy and QCD
Energy Technology Data Exchange (ETDEWEB)
Bloom, E.D.
1982-11-01
The discussion covers quarks as we know them, the classification of ordinary mesons in terms of constituent quarks, hidden charm states and charmed mesons, bottom quarks, positronium as a model for quarti q, quantum chromodynamics and its foundation in experiment, the charmonium model, the mass of states, fine structure and hyperfine structure, classification, widths of states, rate and multipolarity of gamma transitions, questions about bottom, leptonic widths and the determination of Q/sub b/, the mass splitting of the n/sup 3/S/sub 1/ states, the center of gravity of the masses of the n/sup 3/P; states, n/sup 3/ P; fine structure and classification, branching ratios for upsilon' ..-->.. tau chi/sub 6j/ and the tau cascade reactions, hyperfine splitting, and top. (GHT)
Spectroscopy of η′-nucleus bound states at GSI-SIS
Directory of Open Access Journals (Sweden)
Outa Haruhiko
2012-12-01
Full Text Available The η′ meson mass may be reduced due to partial restoration of chiral symmetry. If this is the case, an η′-nucleus system may form a nuclear bound state.We plan to carry out a missing-mass spectroscopy experiment with the 12C(p,d reaction at GSI-SIS. Peak structures corresponding to such a bound state may be observed even in an inclusive measurement, if the decay width is narrow enough.
Transfer Function Bounds for Partial-unit-memory Convolutional Codes Based on Reduced State Diagram
Lee, P. J.
1984-01-01
The performance of a coding system consisting of a convolutional encoder and a Viterbi decoder is analytically found by the well-known transfer function bounding technique. For the partial-unit-memory byte-oriented convolutional encoder with m sub 0 binary memory cells and (k sub 0 m sub 0) inputs, a state diagram of 2(K) (sub 0) was for the transfer function bound. A reduced state diagram of (2 (m sub 0) +1) is used for easy evaluation of transfer function bounds for partial-unit-memory codes.
Nuclear structure of bound states of asymmetric dark matter
Gresham, Moira I.; Lou, Hou Keong; Zurek, Kathryn M.
2017-11-01
Models of asymmetric dark matter (ADM) with a sufficiently attractive and long-range force give rise to stable bound objects, analogous to nuclei in the Standard Model, called nuggets. We study the properties of these nuggets and compute their profiles and binding energies. Our approach, applicable to both elementary and composite fermionic ADM, utilizes relativistic mean field theory, and allows a more systematic computation of nugget properties, over a wider range of sizes and force mediator masses, compared to previous literature. We identify three separate regimes of nugget property behavior corresponding to (1) nonrelativistic and (2) relativistic constituents in a Coulomb-like limit, and (3) saturation in an anti-Coulomb limit when the nuggets are large compared to the force range. We provide analytical descriptions for nuggets in each regime. Through numerical calculations, we are able to confirm our analytic descriptions and also obtain smooth transitions for the nugget profiles between all three regimes. We also find that over a wide range of parameter space, the binding energy in the saturation limit is an O (1 ) fraction of the constituent's mass, significantly larger than expectations in the nonrelativistic case. In a companion paper, we apply our results to the synthesis of ADM nuggets in the early Universe.
Scaling and universality in two dimensions: three-body bound states with short-ranged interactions
Energy Technology Data Exchange (ETDEWEB)
Bellotti, F F; Frederico, T [Instituto Tecnologico de Aeronautica, DCTA, 12.228-900 Sao Jose dos Campos, SP (Brazil); Yamashita, M T [Instituto de Fisica Teorica, UNESP-Univ Estadual Paulista, CP 70532-2, CEP 01156-970, Sao Paulo, SP (Brazil); Fedorov, D V; Jensen, A S; Zinner, N T, E-mail: zinner@phys.au.dk [Department of Physics and Astronomy-Aarhus University, Ny Munkegade, bygn. 1520, DK-8000 Arhus C (Denmark)
2011-10-28
The momentum space zero-range model is used to investigate universal properties of three interacting particles confined to two dimensions. The pertinent equations are first formulated for a system of two identical and one distinct particle and the two different two-body subsystems are characterized by two-body energies and masses. The three-body energy in units of one of the two-body energies is a universal function of the other two-body energy and the mass ratio. We derive convenient analytical formulae for calculations of the three-body energy as a function of these two independent parameters and exhibit the results as universal curves. In particular, we show that the three-body system can have any number of stable bound states. When the mass ratio of the distinct to identical particles is greater than 0.22, we find that at most two stable bound states exist, while for two heavy and one light mass an increasing number of bound states is possible. The specific number of stable bound states depends on the ratio of two-body bound state energies and on the mass ratio, and we map out an energy-mass phase diagram of the number of stable bound states. Realizable systems of both fermions and bosons are discussed in this framework.
Delocalization of a Vacancy across Two Neon Atoms Bound by the van der Waals Force.
Sann, H; Schober, C; Mhamdi, A; Trinter, F; Müller, C; Semenov, S K; Stener, M; Waitz, M; Bauer, T; Wallauer, R; Goihl, C; Titze, J; Afaneh, F; Schmidt, L Ph H; Kunitski, M; Schmidt-Böcking, H; Demekhin, Ph V; Cherepkov, N A; Schöffler, M S; Jahnke, T; Dörner, R
2016-12-23
We experimentally study 2p photoionization of neon dimers (Ne_{2}) at a photon energy of hν=36.56 eV. By postselection of ionization events which lead to a dissociation into Ne^{+}+Ne we obtain the photoelectron angular emission distribution in the molecular frame. This distribution is symmetric with respect to the direction of the charged vs neutral fragment. It shows an inverted Cohen-Fano double slit interference pattern of two spherical waves emitted coherently but with opposite phases from the two atoms of the dimer.
DEFF Research Database (Denmark)
Sadrieva, Zarina F.; Sinev, Ivan S.; Koshelev, Kirill L.
2017-01-01
into resonant states due to leakage into the diffraction channels opening in the substrate. We show how two concurrent loss mechanisms, scattering due to surface roughness and leakage into substrate, contribute to the suppression of the resonance lifetime and specify the condition when one of the mechanisms......Optical bound states in the continuum (BIC) are localized states with energy lying above the light line and having infinite lifetime. Any losses taking place in real systems result in transformation of the bound states into resonant states with finite lifetime. In this Letter, we analyze properties...... becomes dominant. The obtained results provide useful guidelines for practical implementations of structures supporting optical bound states in the continuum....
Atom optics with Rydberg states in inhomogeneous electric fields
Kritsun, Oleg Anton
Atom optics has become subject of intense investigation in recent years. Control of atomic motion is of great importance in atomic physics and applications like lithography or nanofabrication. Neutral atoms are not affected greatly by magnetic or electric field as they don't have a charge or large magnetic and electric moments. But by exciting a neutral atom to a high Rydberg state it is possible to increase its electric moment considerably. The purpose of this thesis is to demonstrate experimentally and theoretically the possibility of creating atom optical elements for the beam of neutral atoms based on the polarizability of highly excited states in an electric field. First this work will present a review of the basic concepts that are used for atom optics and also a discussion of the progress to date in realizations of the neutral atom manipulation techniques. In our earlier experiments deflection and beam-splitting was demonstrated for a beam of neutral Lithium atoms excited in a three-step scheme [3.5, 3.6]. In later experiments, metastable Helium was excited from 23S state to the 33P state using lambda = 389 nm light, and then to the 25--30 S or D states using lambda = 785--815 nm light. Because this was a two-step excitation and it had the higher laser power in the last step, this method increased the percentage of excited atoms by a factor close to 103 compared to the Lithium experiment. Furthermore coherent excitation technique, Stimulated Raman Adiabatic Population Transfer (STIRAP), is investigated in this system, which allows a complete transfer of the atoms from 23S to the Rydberg states. STIRAP is also very tolerant of experimental imperfections such as intensity and frequency fluctuations, Doppler shifts, etc. and can be done with modest laser power. Efficient excitation enables us to do the following atom manipulations in inhomogeneous electric field [3.6, 4.42]. (1) Deflection and reflection; (2) Beam-splitting; (3) Collimation and focusing. Since
Dark Entangled Steady States of Interacting Rydberg Atoms
DEFF Research Database (Denmark)
Dasari, Durga; Mølmer, Klaus
2013-01-01
their short-lived excited states lead to rapid, dissipative formation of an entangled steady state. We show that for a wide range of physical parameters, this entangled state is formed on a time scale given by the strengths of coherent Raman and Rabi fields applied to the atoms, while it is only weakly...
D-state Rydberg electrons interacting with ultracold atoms
Energy Technology Data Exchange (ETDEWEB)
Krupp, Alexander Thorsten
2014-10-02
This thesis was established in the field of ultracold atoms where the interaction of highly excited D-state electrons with rubidium atoms was examined. This work is divided into two main parts: In the first part we study D-state Rydberg molecules resulting from the binding of a D-state Rydberg electron to a ground state rubidium atom. We show that we can address specific rovibrational molecular states by changing our laser detuning and thus create perfectly aligned axial or antialigned toroidal molecules, in good agreement with our theoretical calculations. Furthermore the influence of the electric field on the Rydberg molecules was investigated, creating novel states which show a different angular dependence and alignment. In the second part of this thesis we excite single D-state Rydberg electrons in a Bose-Einstein condensate. We study the lifetime of these Rydberg electrons, the change of the shape of our condensate and the atom losses in the condensate due to this process. Moreover, we observe quadrupolar shape oscillations of the whole condensate created by the consecutive excitation of Rydberg atoms and compare all results to previous S-state measurements. In the outlook we propose a wide range of further experiments including the proposal of imaging a single electron wavefunction by the imprint of its orbit into the Bose-Einstein condensate.
Quantum Cloning of an Unknown 2-Atom State via Entangled Cluster States
Yu, L.-z.; Zhong, F.
2016-06-01
This paper presented a scheme for cloning a 2-atom state in the QED cavity with the help of Victor who is the state's preparer. The cloning scheme has two steps. In the first step, the scheme requires probabilistic teleportation of a 2-atom state that is unknown in advance, and uses a 4-atom cluster state as quantum channel. In the second step, perfect copies of the 2-atom entangled state may be realized with the assistance of Victor. The finding is that our scheme has two outstanding advantages: it is not sensitive to the cavity decay, and Bell state is easy to identify.
Energy Technology Data Exchange (ETDEWEB)
O' Carroll, Michael [Departamento de Matematica Aplicada e Estatistica, ICMC-USP, C.P. 668,13560-970 Sao Carlos, Sao Paulo (Brazil)
2012-07-15
We consider the interaction of particles in weakly correlated lattice quantum field theories. In the imaginary time functional integral formulation of these theories there is a relative coordinate lattice Schroedinger operator H which approximately describes the interaction of these particles. Scalar and vector spin, QCD and Gross-Neveu models are included in these theories. In the weakly correlated regime H=H{sub o}+W where H{sub o}=-{gamma}{Delta}{sub l}, 0 < {gamma} Much-Less-Than 1 and {Delta}{sub l} is the d-dimensional lattice Laplacian: {gamma}={beta}, the inverse temperature for spin systems and {gamma}={kappa}{sup 3} where {kappa} is the hopping parameter for QCD. W is a self-adjoint potential operator which may have non-local contributions but obeys the bound Double-Vertical-Line W(x, y) Double-Vertical-Line Less-Than-Or-Slanted-Equal-To cexp ( -a( Double-Vertical-Line x Double-Vertical-Line + Double-Vertical-Line y Double-Vertical-Line )), a large: exp-a={beta}/{beta}{sub o}{sup (1/2)}({kappa}/{kappa}{sub o}) for spin (QCD) models. H{sub o}, W, and H act in l{sub 2}(Z{sup d}), d Greater-Than-Or-Slanted-Equal-To 1. The spectrum of H below zero is known to be discrete and we obtain bounds on the number of states below zero. This number depends on the short range properties of W, i.e., the long range tail does not increase the number of states.
Bethe–Salpeter bound-state structure in Minkowski space
Energy Technology Data Exchange (ETDEWEB)
Gutierrez, C. [Instituto de Física Teórica, Universidade Estadual Paulista, 01156-970 São Paulo, SP (Brazil); Gigante, V.; Frederico, T. [Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil); Salmè, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, 00185 Roma (Italy); Viviani, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo Pontecorvo 3, 56100 Pisa (Italy); Tomio, Lauro, E-mail: tomio@ift.unesp.br [Instituto de Física Teórica, Universidade Estadual Paulista, 01156-970 São Paulo, SP (Brazil); Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil)
2016-08-10
The quantitative investigation of the scalar Bethe–Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe–Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.
The relativistic bound states of a non-central potential
Indian Academy of Sciences (India)
2017-03-29
Mar 29, 2017 ... K(E + M),. ˜E0 = (1 − 2δ). (47). Obviously, we have chosen the negative solution as the appropriate solution of the quadratic equation in δ so that we can get a positive physical energy state ˜E0. We can now construct the two supersymmetric part- ner potentials as. V+(r) = W2(r)+W (r) = δ(δ − 1) r2. + 2r2+2δ+.
A search for deeply bound kaonic nuclear states
Suzuki, T.; Bhang, H.; Franklin, G.; Gomikawa, K.; Hayano, R. S.; Hayashi, T.; Ishikawa, K.; Ishimoto, S.; Itahashi, K.; Iwasaki, M.; Katayama, T.; Kondo, Y.; Matsuda, Y.; Nakamura, T.; Okada, S.; Outa, H.; Quinn, B.; Sato, M.; Shindo, M.; So, H.; Strasser, P.; Sugimoto, T.; Suzuki, K.; Suzuki, S.; Tomono, D.; Vinodkumar, A. M.; Widmann, E.; Yamazaki, T.; Yoneyama, T.
2005-05-01
We have measured proton and neutron energy spectra by means of time-of-flight (TOF) from 4He( Kstopped-,p/n) reactions (KEK PS E471 experiment). In the proton spectrum, a clear mono-energetic peak was observed under semi-inclusive condition, which was assigned to the formation of a strange tribaryon S 0(3115) with isospin T=1. The mass and width of the state were deduced to be 3117.7-2.0+3.8(syst.)±0.9(stat.) MeV/c and <21.6 MeV/c, respectively, and its main decay mode was ΣNN. In the neutron spectrum, a mono-energetic peak was found as the result of a detailed analysis, which was assigned to the formation of another kind of strange tribaryon S +(3140). The mass and width of the state were deduced to be 3140.5-0.8+3.0(syst.)±2.3(stat.) MeV/c and <21.6 MeV/c, respectively, and its main decay mode was ΣNN. The isospin of the state is assigned to be 0. The results are compared with recent theoretical calculations.
A search for deeply bound kaonic nuclear states
Energy Technology Data Exchange (ETDEWEB)
Suzuki, T. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)]. E-mail: takatosi@nucl.phys.s.u-tokyo.ac.jp; Bhang, H. [Department of Physics, Seoul National University, Shikkim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); Franklin, G. [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Gomikawa, K. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Hayano, R.S. [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Hayashi, T. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Ishikawa, K. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Ishimoto, S. [IPNS, KEK - High Energy Accelerator Research Organization, Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Itahashi, K. [DRI, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Iwasaki, M. [DRI, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Katayama, T. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Kondo, Y. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Matsuda, Y. [DRI, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nakamura, T. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Okada, S. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Outa, H. [IPNS, KEK - High Energy Accelerator Research Organization, Oho, Tsukuba-shi, Ibaraki 305-0801 (Japan); Quinn, B. [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Sato, M. [Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)] [and others
2005-05-30
We have measured proton and neutron energy spectra by means of time-of-flight (TOF) from {sup 4}He(Kstopped-,p/n) reactions (KEK PS E471 experiment). In the proton spectrum, a clear mono-energetic peak was observed under semi-inclusive condition, which was assigned to the formation of a strange tribaryon S{sup 0}(3115) with isospin T=1. The mass and width of the state were deduced to be 3117.7-2.0+3.8(syst.)+/-0.9(stat.) MeV/c2 and 21.6 MeV/c2, respectively, and its main decay mode was {sigma}NN. In the neutron spectrum, a mono-energetic peak was found as the result of a detailed analysis, which was assigned to the formation of another kind of strange tribaryon S{sup +}(3140). The mass and width of the state were deduced to be 3140.5-0.8+3.0(syst.)+/-2.3(stat.) MeV/c2 and 21.6 MeV/c2, respectively, and its main decay mode was {sigma}+/-NN. The isospin of the state is assigned to be 0. The results are compared with recent theoretical calculations.
Subgap in the Surface Bound States Spectrum of Superfluid ^3 He-B with Rough Surface
Nagato, Y.; Higashitani, S.; Nagai, K.
2017-12-01
The subgap structure in the surface bound states spectrum of superfluid ^3 He-B with rough surface is discussed. The subgap is formed by the level repulsion between the surface bound state and the continuum states in the course of multiple scattering by the surface roughness. We show that the level repulsion is originated from the nature of the wave function of the surface bound state that is now recognized as Majorana fermion. We study the superfluid ^3 He-B with a rough surface and in a magnetic field perpendicular to the surface using the quasi-classical Green function together with a random S-matrix model. We calculate the self-consistent order parameters, the spin polarization density and the surface density of states. It is shown that the subgap is found also in a magnetic field perpendicular to the surface. The magnetic field dependence of the transverse acoustic impedance is also discussed.
Single-Atom Gating of Quantum State Superpositions
Energy Technology Data Exchange (ETDEWEB)
Moon, Christopher
2010-04-28
The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space - or Hilbert space - is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral1 can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real-space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.
On the energy of bound states for magnetic Schrödinger operators
DEFF Research Database (Denmark)
Fournais, Søren; Kachmar, Ayman
2009-01-01
is varied near the value where bound states become allowed in the interior of the domain, we show that the energy has a boundary and a bulk component. The estimates rely on coherent states, in particular on the construction of ‘boundary coherent states’, and magnetic Lieb–Thirring estimates.......We provide a leading order semiclassical asymptotics of the energy of bound states for magnetic Neumann Schrödinger operators in two-dimensional (exterior) domains with smooth boundaries. The asymptotics is valid all the way up to the bottom of the essential spectrum. When the spectral parameter...
Study of BB ¯*/DD ¯* bound states in a Bethe-Salpeter approach
He, Jun
2014-10-01
In this work the BB ¯*/DD ¯* system is studied in the Bethe-Salpeter approach with quasipotential approximation. In our calculation both direct and cross diagrams are included in the one-boson-exchange potential. The numerical results indicate the existence of an isoscalar bound state DD ¯* with JPC=1++, which may be related to the X(3872). In the isovector sector, no bound state is produced from the interactions of DD ¯* and BB ¯*, which suggests the molecular state explanations for Zb(10610) and Zc(3900) are excluded.
Study of vison-spinon bound states on the kagome lattice
Shao, Junping; Ghosh, Shivam; Cho, Gil-Young; Lawler, Michael
2014-03-01
We search for low-energy vison-spinon bound states on the kagome lattice. We do this by applying an optimization algorithm to a bosonic spin liquid state with a well separated pair of visons inserted. The resulting wavefunction reveals that the low energy eigen-modes correspond to bound spinon states localized around the visons. We study these modes and their symmetry properties. Our results provide evidence supporting the low energy effective theories of Z2 spin liquids whose bosonic spinons, fermonic spinons and visions are characterized by projective symmetry groups consistent with the expected fusion rules and duality relations.
Excited states of muonium in atomic hydrogen
Indian Academy of Sciences (India)
Muonium formation in excited states in muon-hydrogen charge-exchange collision is investigated using a method developed in a previous paper. Differential cross-section results are found to resemble positronium formation cross-section results of positron-hydrogen charge-exchange problem. Forward differential and ...
Excited states of muonium in atomic hydrogen
Indian Academy of Sciences (India)
Differential cross-section results are found to resemble positronium formation cross-section results of positron–hydrogen charge-exchange problem. Forward ... using velocity scaling are compared with the results of the present calculation. .... to carry out calculations for e− capture by muon into n = 2 and n = 3 states.
Autoionizing states of atoms calculated using generalized sturmians
DEFF Research Database (Denmark)
Avery, James Emil; Avery, John Scales
2005-01-01
energies. A large-Z approximation is discussed, and simple formulas are derived which are valid not only for autoionizing states, but for all states of an isoelectronic atomic series. Diagonalization of a small block of the interelectron repulsion matrix yields roots that can be used for a wide range of Z...
SEARCH FOR eta' (958)-NUCLEUS BOUND STATES BY (p, d) REACTION AT GSI AND FAIR
Fujioka, H.; Ayyad, Y.; Benlliure, J.; Brinkmann, K. -T.; Friedrich, S.; Geissel, H.; Gellanki, J.; Guo, C.; Gutz, E.; Haettner, E.; Harakeh, M. N.; Hayano, R. S.; Higashi, Y.; Hirenzaki, S.; Hornung, C.; Igarashi, Y.; Ikeno, N.; Itahashi, K.; Iwasaki, M.; Jido, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knoebel, R.; Kurz, N.; Metag, V.; Mukha, I.; Nagae, T.; Nagahiro, H.; Nanova, M.; Nishi, T.; Ong, H. J.; Pietri, S.; Prochazka, A.; Rappold, C.; Reiter, M. P.; Rodriguez-Sanchez, J. L.; Scheidenberger, C.; Simon, H.; Sitar, B.; Strmen, P.; Sun, B.; Suzuki, K.; Szarka, I.; Takechi, M.; Tanaka, Y. K.; Tanihata, I.; Terashima, S.; Watanabe, Y. N.; Weick, H.; Widmann, E.; Winfield, J. S.; Xu, X.; Yamakami, H.; Zhao, J.
The mass of the eta' meson is theoretically expected to be reduced at finite density, which indicates the existence of eta'-nucleus bound states. To investigate these states, we perform missing-mass spectroscopy for the (p, d) reaction near the eta' production threshold. The overview of the
Search for eta '(958)-nucleus Bound States by (p,d) Reaction at GSI and FAIR
Fujioka, H.; Ayyad, Y.; Benlliure, J.; Brinkmann, K.-T.; Friedrich, S.; Geissel, H.; Gellanki, J.; Guo, C.; Gutz, E.; Haettner, E.; Harakeh, M. N.; Hayano, R. S.; Higashi, Y.; Hirenzaki, S.; Hornung, C.; Igarashi, Y.; Ikeno, N.; Itahashi, K.; Iwasaki, M.; Jido, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knoebel, R.; Kurz, N.; Metag, V.; Mukha, I.; Nagae, T.; Nagahiro, H.; Nanova, M.; Nishi, T.; Ong, H. J.; Pietri, S.; Prochazka, A.; Rappold, C.; Reiter, M. P.; Rodríguez-Sánchez, J. L.; Scheidenberger, C.; Simon, H.; Sitar, B.; Strmen, P.; Sun, B.; Suzuki, K.; Szarka, I.; Takechi, M.; Tanaka, Y. K.; Tanihata, I.; Terashima, S.; Watanabe, Y. N.; Weick, H.; Widmann, E.; Winfield, J. S.; Xu, X.; Yamakami, H.; Zhao, J.
The mass of the {\\eta}' meson is theoretically expected to be reduced at finite density, which indicates the existence of {\\eta}'-nucleus bound states. To investigate these states, we perform missing-mass spectroscopy for the (p, d) reaction near the {\\eta}' production threshold. The overview of the experimental situation is given and the current status is discussed.
Boson bound states in the β-Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
The bound states of four bosons in the quantum -Fermi–Pasta–Ulam model are investigated and some interesting results are presented using the number conserving approximation combined with the number state method. We find that the relative magnitude of anharmonic coefficient has a significant effect on forming ...
Explicit formula for the Holevo bound for two-parameter qubit-state estimation problem
Suzuki, Jun
2016-04-01
The main contribution of this paper is to derive an explicit expression for the fundamental precision bound, the Holevo bound, for estimating any two-parameter family of qubit mixed-states in terms of quantum versions of Fisher information. The obtained formula depends solely on the symmetric logarithmic derivative (SLD), the right logarithmic derivative (RLD) Fisher information, and a given weight matrix. This result immediately provides necessary and sufficient conditions for the following two important classes of quantum statistical models; the Holevo bound coincides with the SLD Cramér-Rao bound and it does with the RLD Cramér-Rao bound. One of the important results of this paper is that a general model other than these two special cases exhibits an unexpected property: the structure of the Holevo bound changes smoothly when the weight matrix varies. In particular, it always coincides with the RLD Cramér-Rao bound for a certain choice of the weight matrix. Several examples illustrate these findings.
Steady state quantum discord for circularly accelerated atoms
Energy Technology Data Exchange (ETDEWEB)
Hu, Jiawei, E-mail: hujiawei@nbu.edu.cn [Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China); Yu, Hongwei, E-mail: hwyu@hunnu.edu.cn [Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China); Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081 (China)
2015-12-15
We study, in the framework of open quantum systems, the dynamics of quantum entanglement and quantum discord of two mutually independent circularly accelerated two-level atoms in interaction with a bath of fluctuating massless scalar fields in the Minkowski vacuum. We assume that the two atoms rotate synchronically with their separation perpendicular to the rotating plane. The time evolution of the quantum entanglement and quantum discord of the two-atom system is investigated. For a maximally entangled initial state, the entanglement measured by concurrence diminishes to zero within a finite time, while the quantum discord can either decrease monotonically to an asymptotic value or diminish to zero at first and then followed by a revival depending on whether the initial state is antisymmetric or symmetric. When both of the two atoms are initially excited, the generation of quantum entanglement shows a delayed feature, while quantum discord is created immediately. Remarkably, the quantum discord for such a circularly accelerated two-atom system takes a nonvanishing value in the steady state, and this is distinct from what happens in both the linear acceleration case and the case of static atoms immersed in a thermal bath.
Rydberg States of Alkali Metal Atoms on Superfluid Helium Droplets - Theoretical Considerations
Pototschnig, Johann V.; Lackner, Florian; Hauser, Andreas W.; Ernst, Wolfgang E.
2017-06-01
The bound states of electrons on the surface of superfluid helium have been a research topic for several decades. One of the first systems treated was an electron bound to an ionized helium cluster. Here, a similar system is considered, which consists of a helium droplet with an ionized dopant inside and an orbiting electron on the outside. In our theoretical investigation we select alkali metal atoms (AK) as central ions, stimulated by recent experimental studies of Rydberg states for Na, Rb, and Cs attached to superfluid helium nanodroplets. Experimental spectra , obtained by electronic excitation and subsequent ionization, showed blueshifts for low lying electronic states and redshifts for Rydberg states. In our theoretical treatment the diatomic AK^+-He potential energy curves are first computed with ab initio methods. These potentials are then used to calculate the solvation energy of the ion in a helium droplet as a function of the number of atoms. Additional potential terms, derived from the obtained helium density distribution, are added to the undisturbed atomic pseudopotential in order to simulate a 'modified' potential felt by the outermost electron. This allows us to compute a new set of eigenstates and eigenenergies, which we compare to the experimentally observed energy shifts for highly excited alkali metal atoms on helium nanodroplets. A. Golov and S. Sekatskii, Physica B, 1994, 194, 555-556 E. Loginov, C. Callegari, F. Ancilotto, and M. Drabbels, J. Phys. Chem. A, 2011, 115, 6779-6788 F. Lackner, G. Krois, M. Koch, and W. E. Ernst, J. Phys. Chem. Lett., 2012, 3, 1404-1408 F. Lackner, G. Krois, M. Theisen, M. Koch, and W. E. Ernst, Phys. Chem. Chem. Phys., 2011, 13, 18781-18788
Parra-Rivas, Pedro; Gomila, Damia; Colet, Pere; Gelens, Lendert
2017-07-01
Bound states, also called soliton molecules, can form as a result of the interaction between individual solitons. This interaction is mediated through the tails of each soliton that overlap with one another. When such soliton tails have spatial oscillations, locking or pinning between two solitons can occur at fixed distances related with the wavelength of these oscillations, thus forming a bound state. In this work, we study the formation and stability of various types of bound states in the Lugiato-Lefever equation by computing their interaction potential and by analyzing the properties of the oscillatory tails. Moreover, we study the effect of higher order dispersion and noise in the pump intensity on the dynamics of bound states. In doing so, we reveal that perturbations to the Lugiato-Lefever equation that maintain reversibility, such as fourth order dispersion, lead to bound states that tend to separate from one another in time when noise is added. This separation force is determined by the shape of the envelope of the interaction potential, as well as an additional Brownian ratchet effect. In systems with broken reversibility, such as third order dispersion, this ratchet effect continues to push solitons within a bound state apart. However, the force generated by the envelope of the potential is now such that it pushes the solitons towards each other, leading to a null net drift of the solitons. Contribution to the Topical Issue "Theory and Applications of the Lugiato-Lefever Equation", edited by Yanne K. Chembo, Damia Gomila, Mustapha Tlidi, Curtis R. Menyuk.
Toward quantum state tomography of a single polariton state of an atomic ensemble
DEFF Research Database (Denmark)
Christensen, S.L.; Béguin, J.B.; Sørensen, H.L.
2013-01-01
We present a proposal and a feasibility study for the creation and quantum state tomography of a single polariton state of an atomic ensemble. The collective non-classical and non-Gaussian state of the ensemble is generated by detection of a single forward-scattered photon. The state is subsequen...... the feasibility of the proposed method for the detection of a non-classical and non-Gaussian state of the mesoscopic atomic ensemble. This work represents the first attempt at hybrid discrete-continuous variable quantum state processing with atomic memories....... is subsequently characterized by atomic state tomography performed using strong dispersive light-atom interaction followed by a homodyne measurement on the transmitted light. The proposal is backed by preliminary experimental results showing projection noise limited sensitivity and a simulation demonstrating...
Large N Chern-Simons with massive fundamental fermions — A model with no bound states
Energy Technology Data Exchange (ETDEWEB)
Frishman, Yitzhak [Department of Particle Physics and Astrophysics, The Weizmann Institute of Science,Rehovot 76100 (Israel); Sonnenschein, Jacob [The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University,Ramat Aviv 69978 (Israel)
2014-12-29
In a previous paper http://dx.doi.org/10.1007/JHEP12(2013)091, we analyzed the theory of massive fermions in the fundamental representation coupled to a U(N) Chern-Simons gauge theory in three dimensions at level K. It was done in the large N, large K limits where λ=(N/K) was kept fixed. Among other results, we showed there that there are no high mass “quark anti-quark' bound states. Here we show that there are no bound states at all.
Accidental bound states in the continuum in an open Sinai billiard
Pilipchuk, A. S.; Sadreev, A. F.
2017-02-01
The fundamental mechanism of the bound states in the continuum is the full destructive interference of two resonances when two eigenlevels of the closed system are crossing. There is, however, a wide class of quantum chaotic systems which display only avoided crossings of eigenlevels. As an example of such a system we consider the Sinai billiard coupled with two semi-infinite waveguides. We show that notwithstanding the absence of degeneracy bound states in the continuum occur due to accidental decoupling of the eigenstates of the billiard from the waveguides.
S-matrix method for the numerical determination of bound states.
Bhatia, A. K.; Madan, R. N.
1973-01-01
A rapid numerical technique for the determination of bound states of a partial-wave-projected Schroedinger equation is presented. First, one needs to integrate the equation only outwards as in the scattering case, and second, the number of trials necessary to determine the eigenenergy and the corresponding eigenfunction is considerably less than in the usual method. As a nontrivial example of the technique, bound states are calculated in the exchange approximation for the e-/He+ system and l equals 1 partial wave.
Heralded atomic-ensemble quantum memory for photon polarization states
Energy Technology Data Exchange (ETDEWEB)
Tanji, Haruka; Simon, Jonathan [Department of Physics, Harvard University, Cambridge, MA 02138 (United States); Ghosh, Saikat; Bloom, Benjamin; Vuletic, Vladan [Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)], E-mail: vuletic@mit.edu
2009-07-15
We describe the mapping of quantum states between single photons and an atomic ensemble. In particular, we demonstrate a heralded quantum memory based on the mapping of a photon polarization state onto a single collective-spin excitation (magnon) shared between two atomic ensembles. The polarization fidelity above 90(2)% for any input polarization far exceeds the classical limit of 2/3. The process also constitutes a quantum non-destructive probe that detects and regenerates a photon without measuring its polarization.
Upper Bounds on the Degeneracy of the Ground State in Quantum Field Models
Directory of Open Access Journals (Sweden)
Asao Arai
2016-01-01
Full Text Available Axiomatic abstract formulations are presented to derive upper bounds on the degeneracy of the ground state in quantum field models including massless ones. In particular, given is a sufficient condition under which the degeneracy of the ground state of the perturbed Hamiltonian is less than or equal to the degeneracy of the ground state of the unperturbed one. Applications of the abstract theory to models in quantum field theory are outlined.
Seizure states identification in experimental epilepsy using gabor atom analysis.
Sotelo, Arturo; Guijarro, Enrique D; Trujillo, Leonardo
2015-02-15
Epileptic seizures evolve through several states, and in the process the brain signals may change dramatically. Signals from different states share similar features, making it difficult to distinguish them from a time series; the goal of this work is to build a classifier capable of identifying seizure states based on time-frequency features taken from short signal segments. There are different amounts of frequency components within each Time-Frequency window for each seizure state, referred to as the Gabor atom density. Taking short signal segments from the different states and decomposing them into their atoms, the present paper suggests that is possible to identify each seizure state based on the Gabor atom density. The brain signals used in this work were taken form a database of intracranial recorded seizures from the Kindling model. The findings suggest that short signal segments have enough information to be used to derive a classifier able to identify the seizure states with reasonable confidence, particularly when used with seizures from the same subject. Achieving average sensitivity values between 0.82 and 0.97, and area under the curve values between 0.5 and 0.9. The experimental results suggest that seizure states can be revealed by the Gabor atom density; and combining this feature with the epoch's energy produces an improved classifier. These results are comparable with the recently published on state identification. In addition, considering that the order of seizure states is unlikely to change, these results are promising for automatic seizure state classification. Copyright © 2014 Elsevier B.V. All rights reserved.
Radiofrequency-dressed-state potentials for neutral atoms
DEFF Research Database (Denmark)
Hofferberth, S.; Lesanovsky, Igor; Fischer, B.
2006-01-01
Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground and electronica......Potentials for atoms can be created by external fields acting on properties such as magnetic moment, charge, polarizability, or by oscillating fields that couple internal states. The most prominent realization of the latter is the optical dipole potential formed by coupling ground...... and electronically excited states of an atom with light. Here, we present an extensive experimental analysis of potentials derived from radiofrequency (RF) coupling of electronic ground states. The coupling is magnetic and the vector character allows the design of versatile microscopic state-dependent potential...... landscapes. Compared with standard magnetic trapping, we find no additional heating or (collisional) loss up to densities of 1015 atoms cm-3. We demonstrate robust evaporative cooling in RF potentials, which allows easy production of Bose-Einstein condensates in complex potentials. Altogether, this makes RF...
The hyperbolic step potential: Anti-bound states, SUSY partners and Wigner time delays
Energy Technology Data Exchange (ETDEWEB)
Gadella, M. [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain); Kuru, Ş. [Department of Physics, Faculty of Science, Ankara University, 06100 Ankara (Turkey); Negro, J., E-mail: jnegro@fta.uva.es [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain)
2017-04-15
We study the scattering produced by a one dimensional hyperbolic step potential, which is exactly solvable and shows an unusual interest because of its asymmetric character. The analytic continuation of the scattering matrix in the momentum representation has a branch cut and an infinite number of simple poles on the negative imaginary axis which are related with the so called anti-bound states. This model does not show resonances. Using the wave functions of the anti-bound states, we obtain supersymmetric (SUSY) partners which are the series of Rosen–Morse II potentials. We have computed the Wigner reflection and transmission time delays for the hyperbolic step and such SUSY partners. Our results show that the more bound states a partner Hamiltonian has the smaller is the time delay. We also have evaluated time delays for the hyperbolic step potential in the classical case and have obtained striking similitudes with the quantum case. - Highlights: • The scattering matrix of hyperbolic step potential is studied. • The scattering matrix has a branch cut and an infinite number of poles. • The poles are associated to anti-bound states. • Susy partners using antibound states are computed. • Wigner time delays for the hyperbolic step and partner potentials are compared.
Heavy quark bound states in a quark–gluon plasma: Dissociation and recombination
Energy Technology Data Exchange (ETDEWEB)
Blaizot, Jean-Paul, E-mail: jean-paul.blaizot@cea.fr [Institut de Physique Théorique (IPhT), CNRS/UMR 3681, CEA Saclay, F-91191 Gif-sur-Yvette (France); De Boni, Davide [Department of Physics, Swansea University, Swansea SA2 8PP, Wales (United Kingdom); Dipartimento di Fisica, Università degli Studi di Trento, Via Sommarive 14, Povo (Trento) 38123 (Italy); Faccioli, Pietro [Dipartimento di Fisica, Università degli Studi di Trento, Via Sommarive 14, Povo (Trento) 38123 (Italy); INFN-TIFPA, Via Sommarive 14, Povo (Trento) 38123 (Italy); Garberoglio, Giovanni [ECT*-FBK, Via Sommarive 18, Povo (Trento) 38123 (Italy); INFN-TIFPA, Via Sommarive 14, Povo (Trento) 38123 (Italy)
2016-02-15
We present a comprehensive approach to the dynamics of heavy quarks in a quark–gluon plasma, including the possibility of bound state formation and dissociation. In this exploratory paper, we restrict ourselves to the case of an Abelian plasma, but the extension of the techniques used to the non-Abelian case is doable. A chain of well defined approximations leads eventually to a generalized Langevin equation, where the force and the noise terms are determined from a correlation function of the equilibrium plasma, and depend explicitly on the configuration of the heavy quarks. We solve the Langevin equation for various initial conditions, numbers of heavy quark–antiquark pairs and temperatures of the plasma. Results of simulations illustrate several expected phenomena: dissociation of bound states as a result of combined effects of screening of the potential and collisions with the plasma constituent, formation of bound pairs (recombination) that occurs when enough heavy quarks are present in the system.
Shell-model description of weakly bound and unbound nuclear states
Energy Technology Data Exchange (ETDEWEB)
Michel, N. [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN (United States); Joint Institute for Heavy Ion Research, Oak Ridge, TN (United States); Nazarewicz, W. [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN (United States); Warsaw University, Institute of Theoretical Physics, Warsaw (Poland); Ploszajczak, M.; Rotureau, J. [CEA/DSM-CNRS/IN2P3, Grand Accelerateur National d' Ions Lourds (GANIL), Caen (France)
2005-09-01
A consistent description of weakly bound and unbound nuclei requires an accurate description of the particle continuum properties when carrying out multiconfiguration mixing. This is the domain of the Gamow Shell Model (GSM) which is the multiconfigurational shell model in the complex k-plane formulated using a complete Berggren ensemble representing bound single-particle (s.p.) states, s.p. resonances, and non-resonant complex energy continuum states. We discuss the salient features of effective interactions in weakly bound systems and show selected applications of the GSM formalism to p-shell nuclei. Finally, a development of the new non-perturbative scheme based on Density Matrix Renormalization Group methods to select the most significant continuum configurations in GSM calculations is discussed shortly. (orig.)
Effect of substrate on optical bound states in the continuum in 1D photonic structures
Sadrieva, Z. F.; Sinev, I. S.; Samusev, A. K.; Iorsh, I. V.; Koshelev, K. L.; Takayama, O.; Malureanu, R.; Lavrinenko, A. V.; Bogdanov, A. A.
2017-09-01
Optical bound states in the continuum (BIC) are localized states with energy lying above the light line and having infinite lifetime. Any losses taking place in real systems result in transformation of the bound states into resonant states with finite lifetime. In this work, we analyze properties of BIC in CMOS-compatible one-dimensional photonic structure based on silicon-on-insulator wafer at telecommunication wavelengths, where the absorption of silicon is negligible. We reveal that a high-index substrate could destroy both off-Γ BIC and in-plane symmetry protected at-Γ BIC turning them into resonant states due to leakage into the diffraction channels opening in the substrate.
Energy Technology Data Exchange (ETDEWEB)
Kashlev, Y.A., E-mail: yakashlev@yandex.ru
2017-04-15
Evolution of vibration relaxation of hydrogen atoms in metals with the close-packed lattice at high and medium temperatures is investigated based on non-equilibrium statistical thermodynamics, in that number on using the retarded two-time Green function method. In accordance with main kinetic equation – the generalized Fokker- Plank- Kolmogorov equation, anharmonism of hydrogen atoms vibration in potential wells does not make any contribution to collision effects. It influences the relaxation processes at the expense of interference of fourth order anharmonism with single-phonon scattering on impurity hydrogen atoms. Therefore, the total relaxation time of vibration energy of system metal-hydrogen is written as a product of two factors: relaxation time of system in harmonic approximation and dimensionless anharmonic attenuation of quantum hydrogen state.
Coherent excitation of a single atom to a Rydberg state
DEFF Research Database (Denmark)
Miroshnychenko, Yevhen; Gaëtan, Alpha; Evellin, Charles
2010-01-01
We present the coherent excitation of a single Rubidium atom to the Rydberg state 58d3/2 using a two-photon transition. The experimental setup is described in detail, as are experimental techniques and procedures. The coherence of the excitation is revealed by observing Rabi oscillations between...
Morse potential, symmetric Morse potential and bracketed bound-state energies
Czech Academy of Sciences Publication Activity Database
Znojil, Miloslav
2016-01-01
Roč. 31, č. 14 (2016), s. 1650088 ISSN 0217-7323 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : quantum bound states * special functions * Morse potential * symmetrized Morse potential * upper and lower energy estimates * computer-assisted symbolic manipulations Subject RIV: BE - Theoretical Physics Impact factor: 1.165, year: 2016
Quasi bound states in the continuum with few unit cells of photonic crystal slab
DEFF Research Database (Denmark)
Taghizadeh, Alireza; Chung, Il-Sug
2017-01-01
Bound states in the continuum (BICs) in photonic crystal slabs represent the resonances with an infinite quality (Q)-factor, occurring above the light line for an infinitely periodic structure. We show that a set of BICs can turn into quasi-BICs with a very high Q-factor even for two or three unit...
Czech Academy of Sciences Publication Activity Database
Znojil, Miloslav
2017-01-01
Roč. 96, č. 1 (2017), č. článku 012127. ISSN 2469-9926 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : non-Hermitian * PT symmetric * bound states Subject RIV: BE - Theoretical Physics Impact factor: 2.925, year: 2016
Boson bound states in the β-Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
paper, we report our results on boson bound states (BBS) in the β-FPU model. The paper is organized as follows. In §2, we first describe the model and introduce the quantization scheme, then, at 4-quanta level, we introduce the basis we used to diagonalize the effective. Hamiltonian. The energy spectrum of the model at ...
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.
Effects of local periodic driving on transport and generation of bound states
Agarwala, Adhip; Sen, Diptiman
2017-09-01
We periodically kick a local region in a one-dimensional lattice and demonstrate, by studying wave packet dynamics, that the strength and the time period of the kicking can be used as tuning parameters to control the transmission probability across the region. Interestingly, we can tune the transmission to zero which is otherwise impossible to do in a time-independent system. We adapt the nonequilibrium Green's function method to take into account the effects of periodic driving; the results obtained by this method agree with those found by wave packet dynamics if the time period is small. We discover that Floquet bound states can exist in certain ranges of parameters; when the driving frequency is decreased, these states get delocalized and turn into resonances by mixing with the Floquet bulk states. We extend these results to incorporate the effects of local interactions at the driven site, and we find some interesting features in the transmission and the bound states.
η condensate of fermionic atom pairs via adiabatic state preparation.
Kantian, A; Daley, A J; Zoller, P
2010-06-18
We discuss how an η condensate, corresponding to an exact excited eigenstate of the Fermi-Hubbard model, can be produced with cold atoms in an optical lattice. Using time-dependent density matrix renormalization group methods, we analyze a state preparation scheme beginning from a band insulator state in an optical superlattice. This state can act as an important test case, both for adiabatic preparation methods and the implementation of the many-body Hamiltonian, and measurements on the final state can be used to help detect associated errors.
Atomic homodyne detection of continuous-variable entangled twin-atom states.
Gross, C; Strobel, H; Nicklas, E; Zibold, T; Bar-Gill, N; Kurizki, G; Oberthaler, M K
2011-11-30
Historically, the completeness of quantum theory has been questioned using the concept of bipartite continuous-variable entanglement. The non-classical correlations (entanglement) between the two subsystems imply that the observables of one subsystem are determined by the measurement choice on the other, regardless of the distance between the subsystems. Nowadays, continuous-variable entanglement is regarded as an essential resource, allowing for quantum enhanced measurement resolution, the realization of quantum teleportation and quantum memories, or the demonstration of the Einstein-Podolsky-Rosen paradox. These applications rely on techniques to manipulate and detect coherences of quantum fields, the quadratures. Whereas in optics coherent homodyne detection of quadratures is a standard technique, for massive particles a corresponding method was missing. Here we report the realization of an atomic analogue to homodyne detection for the measurement of matter-wave quadratures. The application of this technique to a quantum state produced by spin-changing collisions in a Bose-Einstein condensate reveals continuous-variable entanglement, as well as the twin-atom character of the state. Our results provide a rare example of continuous-variable entanglement of massive particles. The direct detection of atomic quadratures has applications not only in experimental quantum atom optics, but also for the measurement of fields in many-body systems of massive particles.
Identifying local structural states in atomic imaging by computer vision.
Laanait, Nouamane; Ziatdinov, Maxim; He, Qian; Borisevich, Albina
2017-01-01
The availability of atomically resolved imaging modalities enables an unprecedented view into the local structural states of materials, which manifest themselves by deviations from the fundamental assumptions of periodicity and symmetry. Consequently, approaches that aim to extract these local structural states from atomic imaging data with minimal assumptions regarding the average crystallographic configuration of a material are indispensable to advances in structural and chemical investigations of materials. Here, we present an approach to identify and classify local structural states that is rooted in computer vision. This approach introduces a definition of a structural state that is composed of both local and nonlocal information extracted from atomically resolved images, and is wholly untethered from the familiar concepts of symmetry and periodicity. Instead, this approach relies on computer vision techniques such as feature detection, and concepts such as scale invariance. We present the fundamental aspects of local structural state extraction and classification by application to simulated scanning transmission electron microscopy images, and analyze the robustness of this approach in the presence of common instrumental factors such as noise, limited spatial resolution, and weak contrast. Finally, we apply this computer vision-based approach for the unsupervised detection and classification of local structural states in an experimental electron micrograph of a complex oxides interface, and a scanning tunneling micrograph of a defect-engineered multilayer graphene surface.
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Energy Technology Data Exchange (ETDEWEB)
Doyon, Benjamin, E-mail: benjamin.doyon@kcl.ac.uk
2015-03-15
Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Directory of Open Access Journals (Sweden)
Benjamin Doyon
2015-03-01
Full Text Available Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Resolving the Spatial Structures of Bound Hole States in Black Phosphorus.
Qiu, Zhizhan; Fang, Hanyan; Carvalho, Alexandra; Rodin, A S; Liu, Yanpeng; Tan, Sherman J R; Telychko, Mykola; Lv, Pin; Su, Jie; Wang, Yewu; Castro Neto, A H; Lu, Jiong
2017-11-08
Understanding the local electronic properties of individual defects and dopants in black phosphorus (BP) is of great importance for both fundamental research and technological applications. Here, we employ low-temperature scanning tunnelling microscope (LT-STM) to probe the local electronic structures of single acceptors in BP. We demonstrate that the charge state of individual acceptors can be reversibly switched by controlling the tip-induced band bending. In addition, acceptor-related resonance features in the tunnelling spectra can be attributed to the formation of Rydberg-like bound hole states. The spatial mapping of the quantum bound states shows two distinct shapes evolving from an extended ellipse shape for the 1s ground state to a dumbbell shape for the 2p x excited state. The wave functions of bound hole states can be well-described using the hydrogen-like model with anisotropic effective mass, corroborated by our theoretical calculations. Our findings not only provide new insight into the many-body interactions around single dopants in this anisotropic two-dimensional material but also pave the way to the design of novel quantum devices.
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
Energy Technology Data Exchange (ETDEWEB)
Hetzheim, Henrik
2009-01-14
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Probing the superconducting state via Andreev bound states in (La,Ce){sub 2}CuO{sub 4}
Energy Technology Data Exchange (ETDEWEB)
Wagenknecht, Michael; Scharinger, Sebastian; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut - Experimentalphysik II and Center for Collective Quantum Phenomena, Universitaet Tuebingen (Germany); Graser, Siegfried; Schopohl, Nils [Institut fuer Theoretische Physik, Universitaet Tuebingen (Germany); Chesca, Boris [Department of Physics, Loughborough University (United Kingdom); Tsukada, Aiko [NTT Basic Research Laboratories, Atsugi-shi (Japan); Goennenwein, Sebastian T.B.; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)
2008-07-01
We present quasiparticle tunneling data of (La,Ce){sub 2}CuO{sub 4} thin film bicrystal junctions. The differential conductance in the superconducting state shows a pronounced zero bias conductance peak (ZBCP). This peak is attributed to zero energy surface Andreev bound states due to the d-wave symmetry of the order parameter in this electron doped cuprate. Such bound states are closely related to the macroscopic phase coherence of the superconducting state. Hence the ZBCP due to these bound states must disappear at or below the upper critical field B{sub c2}(T). By following the disappearance of the ZBCP in the B-T-phase diagram we find a lower bound for B{sub c2}(0){approx}25 T which is higher than values reported previously for any electron doped cuprate. Following this observation we suggest a modified B-T-phase diagram with a larger region of superconductivity, leaving less room for a possible pseudogap phase.
Electron collisions with BF{sup +}: bound and continuum states of BF
Energy Technology Data Exchange (ETDEWEB)
Chakrabarti, K [Department of Mathematics, Scottish Church College, 1 and 3 Urquhart Sq., Kolkata 700006 (India); Schneider, I F [Laboratoire Ondes et Milieux Complexes (LOMC) CNRS-FRE-3102, Universite du Havre, 25, rue Philippe Lebon, BP 540, 76058 Le Havre (France); Tennyson, Jonathan, E-mail: j.tennyson@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower St., London WC1E 6BT (United Kingdom)
2011-03-14
Rydberg and continuum states of the BF molecule are studied as a function of geometry using an electron collision formalism in the framework of the R-matrix method. Up to 14 BF{sup +} target states are used in a close-coupling expansion and bound states are searched for as negative energy solutions of the scattering calculation. Potential energy curves and quantum defects are obtained for the excited states of BF. Resonance positions and widths are also calculated for Feshbach resonances in the system. The data obtained can be used to model dissociative recombination of the BF{sup +} molecular ion.
Magnetic field dependence of the atomic collapse state in graphene
Moldovan, D.; Ramezani Masir, M.; Peeters, F. M.
2018-01-01
Quantum electrodynamics predicts that heavy atoms (Z > Zc ≈ 170 ) will undergo the process of atomic collapse where electrons sink into the positron continuum and a new family of so-called collapsing states emerges. The relativistic electrons in graphene exhibit the same physics but at a much lower critical charge (Zc ≈ 1 ) which has made it possible to confirm this phenomenon experimentally. However, there exist conflicting predictions on the effect of a magnetic field on atomic collapse. These theoretical predictions are based on the continuum Dirac–Weyl equation, which does not have an exact analytical solution for the interplay of a supercritical Coulomb potential and the magnetic field. Approximative solutions have been proposed, but because the two effects compete on similar energy scales, the theoretical treatment varies depending on the regime which is being considered. These limitations are overcome here by starting from a tight-binding approach and computing exact numerical results. By avoiding special limit cases, we found a smooth evolution between the different regimes. We predict that the atomic collapse effect persists even after the magnetic field is activated and that the critical charge remains unchanged. We show that the atomic collapse regime is characterized: (1) by a series of Landau level anticrossings and (2) by the absence of \\sqrt{B} scaling of the Landau levels with regard to magnetic field strength.
Hadamard States for the Klein-Gordon Equation on Lorentzian Manifolds of Bounded Geometry
Gérard, Christian; Oulghazi, Omar; Wrochna, Michał
2017-06-01
We consider the Klein-Gordon equation on a class of Lorentzian manifolds with Cauchy surface of bounded geometry, which is shown to include examples such as exterior Kerr, Kerr-de Sitter spacetime and the maximal globally hyperbolic extension of the Kerr outer region. In this setup, we give an approximate diagonalization and a microlocal decomposition of the Cauchy evolution using a time-dependent version of the pseudodifferential calculus on Riemannian manifolds of bounded geometry. We apply this result to construct all pure regular Hadamard states (and associated Feynman inverses), where regular refers to the state's two-point function having Cauchy data given by pseudodifferential operators. This allows us to conclude that there is a one-parameter family of elliptic pseudodifferential operators that encodes both the choice of (pure, regular) Hadamard state and the underlying spacetime metric.
Skyrmion-induced bound states on the surface of three-dimensional topological insulators
Energy Technology Data Exchange (ETDEWEB)
Andrikopoulos, Dimitrios, E-mail: dimitrios.andrikopoulos@imec.be; De Boeck, Jo [KU Leuven, ESAT, Kasteelpark Arenberg 10, Leuven B-3001 (Belgium); imec, Kapeeldreef 75, Leuven 3001 (Belgium); Sorée, Bart, E-mail: bart.soree@imec.be [KU Leuven, ESAT, Kasteelpark Arenberg 10, Leuven B-3001 (Belgium); Physics Department, Condensed Matter Theory, Universiteit Antwerpen, Groenenborgerlaan 171, Antwerpen B-2020 (Belgium); imec, Kapeeldreef 75, Leuven 3001 (Belgium)
2016-05-21
The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Néel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number N{sub Sk}. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region.
Two-body bound and edge states in the extended SSH Bose-Hubbard model
Di Liberto, M.; Recati, A.; Carusotto, I.; Menotti, C.
2017-07-01
We study the bosonic two-body problem in a Su-Schrieffer-Heeger dimerized chain with on-site and nearest-neighbor interactions. We find two classes of bound states. The first, similar to the one induced by on-site interactions, has its center of mass on the strong link, whereas the second, existing only thanks to nearest-neighbor interactions, is centered on the weak link. We identify energy crossings between these states and analyse them using exact diagonalization and perturbation theory. In the presence of open boundary conditions, novel strongly-localized edge-bound states appear in the spectrum as a consequence of the interplay between lattice geometry, on-site and nearest-neighbor interactions. Contrary to the case of purely on-site interactions, such EBS persist even in the strongly interacting regime.
Three-body bound states with zero-range interaction in the Bethe-Salpeter approach
Ydrefors, E.; Alvarenga Nogueira, J. H.; Gigante, V.; Frederico, T.; Karmanov, V. A.
2017-07-01
The Bethe-Salpeter equation for three bosons with zero-range interaction is solved for the first time. For comparison the light-front equation is also solved. The input is the two-body scattering length and the outputs are the three-body binding energies, Bethe-Salpeter amplitudes and light-front wave functions. Three different regimes are analyzed: (i) For weak enough two-body interaction the three-body system is unbound. (ii) For stronger two-body interaction a three-body bound state appears. It provides an interesting example of a deeply bound Borromean system. (iii) For even stronger two-body interaction this state becomes unphysical with a negative mass squared. However, another physical (excited) state appears, found previously in light-front calculations. The Bethe-Salpeter approach implicitly incorporates three-body forces of relativistic origin, which are attractive and increase the binding energy.
Klees, Raffael L.; Rastelli, Gianluca; Belzig, Wolfgang
2017-10-01
Inspired by recent experiments, we study a short superconducting junction of length L ≪ξ (coherence length) inserted in a dc-SQUID containing an ancillary Josephson tunnel junction. We evaluate the nonequilibrium occupation of the Andreev bound states (ABS) for the case of a conventional junction and a topological junction, with the latter case of ABS corresponding to a Majorana mode. We take into account small phase fluctuations of the Josephson tunnel junction, acting as a damped LC resonator, and analyze the role of the distribution of the quasiparticles of the continuum assuming that these quasiparticles are in thermal distribution with an effective temperature different from the environmental temperature. We also discuss the effect of strong photon irradiation in the junction leading to a nonequilibrium occupation of the ABS. We systematically compare the occupations of the bound states and the supercurrents carried by these states for conventional and topological junctions.
Jittangprasert, Piyada; Wilairat, Prapin; Pootrakul, Pensri
2004-12-01
This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand for binding iron from low molecular weight iron complexes present in the serum but without removing iron from the transferrin protein. After ultrafiltration the Fe (III)-NTA complex was then quantified by both methods. Kinetic study of the rate of the Fe (II)-BPT complex formation for various excess amounts of NTA ligand was also carried out. The kinetic data show that a minimum time duration (> 60 minutes) is necessary for complete complex formation when large excess of NTA is used. Calibration curves given by colorimetric and ETAAS methods were linear over the range of 0.15-20 microM iron (III). The colorimetric and ETAAS methods exhibited detection limit (3sigma) of 0.13 and 0.14 microM, respectively. The NTBI concentrations from 55 thalassemic serum samples measured employing BPT as chromogen were statistically compared with the results determined by ETAAS. No significant disagreement at 95% confidence level was observed. It is, therefore, possible to select any one of these two techniques for determination of NTBI in serum samples of thalassemic patients. However, the colorimetric procedure requires a longer analysis time because of a slow rate of exchange of NTA ligand with BPT, leading to the slow rate of formation of the colored complex.
Structure and orientation of dynorphin bound to lipid bilayers by 13C solid-state NMR
Uezono, Takiko; Toraya, Shuichi; Obata, Maki; Nishimura, Katsuyuki; Tuzi, Satoru; Saitô, Hazime; Naito, Akira
2005-07-01
Secondary structure and orientation of dynorphin bound to dimyristoylphosphatidylcholine (DMPC) bilayer were investigated by solid-state 13C NMR spectroscopy. For this purpose, 13C NMR spectra of the site-specifically 13C-labeled dynorphin were measured in the membrane-bound state under static, magic angle spinning (MAS), and slow MAS conditions. In the static experiment, magnetically oriented vesicle system (MOVS) induced by dynorphin was successfully used to investigate the orientation of dynorphin bound to the lipid bilayers. It was found that dynorphin adopts an α-helical structure in the N-terminus from Gly 2 to Leu 5 by analyses of the isotropic chemical shifts obtained from the MAS experiments. In contrast, it adopts disordered conformations from the center to the C-terminus and is located on the membrane surface. The static 13C NMR spectra indicated that MOVS-bound dynorphin was oriented to the magnetic field and rotated rapidly about the bilayer normal. Subsequently, we analyzed the 13C chemical shift tensors of carbonyl carbons in the peptide backbone by considering the rotational motion of the N-terminal α-helix. It was revealed that the N-terminal α-helix is inserted into the membrane with the tilt angle of 21° to the bilayer normal. This structure suggests a possibility that dynorphin interacts with the extracellular loop II of the κ-receptor through a helix-helix interaction.
Wu, Jin-Lei; Ji, Xin; Zhang, Shou
2017-04-11
We propose a dressed-state scheme to achieve shortcuts to adiabaticity in atom-cavity quantum electrodynamics for speeding up adiabatic two-atom quantum state transfer and maximum entanglement generation. Compared with stimulated Raman adiabatic passage, the dressed-state scheme greatly shortens the operation time in a non-adiabatic way. By means of some numerical simulations, we determine the parameters which can guarantee the feasibility and efficiency both in theory and experiment. Besides, numerical simulations also show the scheme is robust against the variations in the parameters, atomic spontaneous emissions and the photon leakages from the cavity.
Wu, Jin-Lei; Ji, Xin; Zhang, Shou
2017-04-01
We propose a dressed-state scheme to achieve shortcuts to adiabaticity in atom-cavity quantum electrodynamics for speeding up adiabatic two-atom quantum state transfer and maximum entanglement generation. Compared with stimulated Raman adiabatic passage, the dressed-state scheme greatly shortens the operation time in a non-adiabatic way. By means of some numerical simulations, we determine the parameters which can guarantee the feasibility and efficiency both in theory and experiment. Besides, numerical simulations also show the scheme is robust against the variations in the parameters, atomic spontaneous emissions and the photon leakages from the cavity.
Coherent manipulation of Andreev states in superconducting atomic contacts.
Janvier, C; Tosi, L; Bretheau, L; Girit, Ç Ö; Stern, M; Bertet, P; Joyez, P; Vion, D; Esteve, D; Goffman, M F; Pothier, H; Urbina, C
2015-09-11
Coherent control of quantum states has been demonstrated in a variety of superconducting devices. In all of these devices, the variables that are manipulated are collective electromagnetic degrees of freedom: charge, superconducting phase, or flux. Here we demonstrate the coherent manipulation of a quantum system based on Andreev bound states, which are microscopic quasi-particle states inherent to superconducting weak links. Using a circuit quantum electrodynamics setup, we performed single-shot readout of this Andreev qubit. We determined its excited-state lifetime and coherence time to be in the microsecond range. Quantum jumps and parity switchings were observed in continuous measurements. In addition to having possible quantum information applications, such Andreev qubits are a test-bed for the physics of single elementary excitations in superconductors. Copyright © 2015, American Association for the Advancement of Science.
Afzal, Muhammad Imran; Lee, Yong Tak
2016-01-01
Von Neumann and Wigner theorized bounding of asymmetric eigenstates and anti-crossing of symmetric eigenstates. Experiments have shown that owing to anti-crossing and similar radiation rates, graphene-like resonance of inhomogeneously strained photonic eigenstates can generate pseudomagnetic field, bandgaps and Landau levels, while dissimilar rates induce non-Hermicity. Here, we showed experimentally higher-order supersymmetry and quantum phase transitions by resonance between similar one dimensional lattices. The lattices consisted of inhomgeneously strain-like phases of triangular solitons. The resonance created two dimensional inhomogeneously deformed photonic graphene. All parent eigenstates are annihilated. Where eigenstates of mildly strained solitons are annihilated with similar (power law) rates through one tail only and generated Hermitianally bounded eigenstates. The strongly strained solitons, positive defects are annihilated exponentially through both tails with dissimilar rates. Which bounded eig...
Choudhari, Tarun; Deo, Nivedita
2017-01-01
A superconductor-topological insulator-superconductor (S/TI/S) junction having normal region at angle θ is studied theoretically to investigate the junction angle dependency of the Andreev reflection and the formation of the Andreev bound states in the step and planar S/TI/S structures. It is found that the Andreev reflection becomes θ dependent only in the presence of the potential barrier at the TI/S interface. In particular, the step and planar TI/S junction have totally different conductive behavior with bias voltage and potential barrier in the regime of retro and specular Andreev reflection. Interestingly, we find that the elliptical cross section of Dirac cone, an important feature of topological insulator with step surface defect, affects the Fabry-Perot resonance of the Andreev reflection induced Andreev bound states (which become Majorana zero energy states at low chemical potential) in the step S/TI/S structure. Unlike the usual planar S/TI/S structures, we find these ellipticity affected Andreev bound states lead to non-monotonic Josephson super-current in the step S/TI/S structure whose non-monotonicity can be controlled with the use of the potential barrier, which may find applications in nanoelectronics.
Electronic state of europium atoms on surface of oxidized tungsten
Davydov, S Y
2001-01-01
The energy scheme of the europium atoms adsorption system on the tungsten surface, coated with the oxygen monolayer, is considered. The evaluations of the europium adatoms charged state on the oxidized tungsten surface are performed. It is established, that europium, adsorbed at the oxidized tungsten surface, is a positive ion with the charge close to the unit. The zonal scheme of the Eu-O/W adsorption system for the europium low and high concentrations is proposed
The mental health state of atomic bomb survivors
Energy Technology Data Exchange (ETDEWEB)
Nakane, Yoshibumi; Imamura, Yoshihiro; Yoshitake, Kazuyasu; Honda, Sumihisa; Mine, Mariko; Hatada, Keiko; Tomonaga, Masao [Nagasaki Univ. (Japan). School of Medicine; Tagawa, Masuko
1997-03-01
Our department of Neuropsychiatry has clarified the clinical features of several mental disorders and surveyed the causes of those disorders from the psychosocial aspect using the methodology of epidemiological psychiatric approach. Using this previous research experience, we began a long-planned study to examine the mental health state of atomic bomb survivors. Fifty-one years have passed since the atomic bombing, and the survivors must have suffered various psychosocial stresses, other than any direct effect on the central nervous system from exposure to radiation, and it is assumed that victims` mental state has been affected in various ways as a result. The subjects of the survey were 7,670 people who had regular health examinations for atomic bomb survivors during the study period of three years and who consented to participate in the study. Of the total, 226 subjects were selected for a second phase according to the results of the General Health Questionnaire 12-item Version which was used in the first phase of the survey. The results were as follows: 1. The distance from the hypocenter was related to the degree of ill health, and the percentage of people with a high score was greater among those exposed to the atomic bomb in proximity to the hypocenter. 2. 14.6% of the subjects were diagnosed as having some kind of mental disorders according to clinical interviews by trained psychiatrists. These results had not expected prior to the study. On the based of the study, we will try to establish a mental health support system for atomic bomb survivors. (author)
Light-Front Hamiltonian Approach to the Bound-State Problem in Quantum Electrodynamics
Jones, Billy D.
1997-10-01
Why is the study of the Lamb shift in hydrogen, which at the level of detail found in this paper was largely completed by Bethe in 1947, of any real interest today? While completing such a calculation using new techniques may be very interesting for formal and academic reasons, our primary motivation is to lay groundwork for precision bound-state calculations in QCD. The Lamb shift provides an excellent pedagogical tool for illustrating light-front Hamiltonian techniques, which are not widely known; but more importantly it presents three of the central dynamical and computational problems that we must face to make these techniques useful for solving QCD: How does a constituent picture emerge in a gauge field theory? How do bound-state energy scales emerge non-perturbatively? How does rotational symmetry emerge in a non-perturbative light-front calculation?
Robustness of Majorana bound states in the short-junction limit
Sticlet, Doru; Nijholt, Bas; Akhmerov, Anton
2017-03-01
We study the effects of strong coupling between a superconductor and a semiconductor nanowire on the creation of the Majorana bound states, when the quasiparticle dwell time in the normal part of the nanowire is much shorter than the inverse superconducting gap. This "short-junction" limit is relevant for the recent experiments using the epitaxially grown aluminum characterized by a transparent interface with the semiconductor and a small superconducting gap. We find that the small superconducting gap does not have a strong detrimental effect on the Majorana properties. Specifically, both the critical magnetic field required for creating a topological phase and the size of the Majorana bound states are independent of the superconducting gap. The critical magnetic field scales with the wire cross section, while the relative importance of the orbital and Zeeman effects of the magnetic field is controlled by the material parameters only: g factor, effective electron mass, and the semiconductor-superconductor interface transparency.
Bound-state field-theory approach to proton-structure effects in muonic hydrogen
Mohr, Peter J.; Griffith, J.; Sapirstein, J.
2013-05-01
A bound-state field-theory approach to muonic hydrogen is set up using a variant of the Furry representation in which the lowest-order Hamiltonian describes a muon in the presence of a point Coulomb field, but the origin of the binding field is taken to be three charged quarks in the proton, which are modeled as Dirac particles that move freely within a spherical well. Bound-state field-theory techniques are used to evaluate one- and two-photon effects. Particular attention is paid to two-photon-exchange diagrams, which include the effect of proton polarizability. In addition, the modification of the electromagnetic self energy of the proton by the electric field of the muon is examined. Finally, the model is used to carry out a calculation of the static electric polarizability of the proton.
Lower Bounds on the Capacity of the Relay Channel with States at the Source
Directory of Open Access Journals (Sweden)
Abdellatif Zaidi
2009-01-01
Full Text Available We consider a state-dependent three-terminal full-duplex relay channel with the channel states noncausally available at only the source, that is, neither at the relay nor at the destination. This model has application to cooperation over certain wireless channels with asymmetric cognition capabilities and cognitive interference relay channels. We establish lower bounds on the channel capacity for both discrete memoryless (DM and Gaussian cases. For the DM case, the coding scheme for the lower bound uses techniques of rate-splitting at the source, decode-and-forward (DF relaying, and a Gel'fand-Pinsker-like binning scheme. In this coding scheme, the relay decodes only partially the information sent by the source. Due to the rate-splitting, this lower bound is better than the one obtained by assuming that the relay decodes all the information from the source, that is, full-DF. For the Gaussian case, we consider channel models in which each of the relay node and the destination node experiences on its link an additive Gaussian outside interference. We first focus on the case in which the links to the relay and to the destination are corrupted by the same interference; and then we focus on the case of independent interferences. We also discuss a model with correlated interferences. For each of the first two models, we establish a lower bound on the channel capacity. The coding schemes for the lower bounds use techniques of dirty paper coding or carbon copying onto dirty paper, interference reduction at the source and decode-and-forward relaying. The results reveal that, by opposition to carbon copying onto dirty paper and its root Costa's initial dirty paper coding (DPC, it may be beneficial in our setup that the informed source uses a part of its power to partially cancel the effect of the interference so that the uninformed relay benefits from this cancellation, and so the source benefits in turn.
Electroproduction of strangeness on (Lambda)H-3,4 bound states on helium
Energy Technology Data Exchange (ETDEWEB)
F. Dohrmann; D. Abbott; A. Ahmidouch; P. Ambrozewicz; C. S. Armstrong; J. Arrington; R. Asaturyan; K. Assamagan; S. Avery; K. Bailey; S. Beedoe; H. Bitao; H. Breuer; D. S. Brown; R. Carlini; J. Cha; N. Chant; E. Christy; A. Cochran; L. Cole; G. Collins; C. Cothran; J. Crowder; W. J. Cummings; S. Danagoulian; F. Duncan; J. Dunne; D. Dutta; T. Eden; M. Elaasar; R. Ent; L. Ewell; H. Fenker; H. T. Fortune; Y. Fujii; L. Gan; H. Gao; K. Garrow; D. F. Geesaman; P. Gueye; K. Gustafsson; K. Hafidi; J. O. Hansen; W. Hinton; H. E. Jackson; H. Juengst; C. Keppel; A. Klein; D. Koltenuk; Y. Liang; J. H. Liu; A. Lung; D. Mack; R. Madey; P. Markowitz; C. J. Martoff; D. Meekins; J. Mitchell; T. Miyoshi; H. Mkrtchyan; R. Mohring; S. K. Mtingwa; B. Mueller; T. G. O& #x27; Neill; G. Niculescu; I. Niculescu; D. Potterveld; J. W. Price; B. A. Raue; P. E. Reimer; J. Reinhold;
2005-05-01
The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q{sup 2} approx. 0.35 GeV{sup 2} at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed.
Bound-states of D-branes in L-R asymmetric superstring vacua
Bianchi, Massimo
2008-01-01
We discuss bound-states of D-branes in truly L-R asymmetric and thus non-geometric Type II vacuum configurations with extended supersymmetry. We argue for their stability as a result of residual supersymmetry and coupling to R-R potentials surviving in the massless spectrum. We then identify the open string excitations of these L-R asymmetric BPS D-branes. Finally, we briefly comment on possible applications and extensions.
Possible evidence for narrow bound states related to the $p\\overline{p}$ system
Pavlopoulos, P; Blüm, P; Fransson, K; Guigas, R; Hassler, N; Izycki, M; Koch, H; Nilsson, A; Poth, H; Suffert, Martin; Towscher, L; Zioutas, Konstantin
1978-01-01
A search for mesonic structure in the pp system below threshold is reported. Bound states are observed for the first time by observing gamma -rays accompanying the annihilation of stopped p in liquid hydrogen. A novel NaI handling technique is reported. Three narrow structures are observed related to the pp system at 183, 216 and 420 MeV, with confidence levels of 1%, 2.5% and 1.8% respectively. (47 refs).
Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors
Energy Technology Data Exchange (ETDEWEB)
Izquierdo, A. Alonso [Departamento de Matematica Aplicada, Universidad de Salamanca,Facultad de Ciencias Agrarias y Ambientales,Av. Filiberto Villalobos 119, E-37008 Salamanca (Spain); Fuertes, W. Garcia [Departamento de Fisica, Universidad de Oviedo, Facultad de Ciencias,Calle Calvo Sotelo s/n, E-33007 Oviedo (Spain); Guilarte, J. Mateos [Departamento de Fisica Fundamental, Universidad de Salamanca, Facultad de Ciencias,Plaza de la Merced, E-37008 Salamanca (Spain)
2016-05-12
In this paper the zero modes of fluctuation of cylindrically symmetric self-dual vortices are analyzed and described in full detail. These BPS topological defects arise at the critical point between Type II and Type I superconductors, or, equivalently, when the masses of the Higgs particle and the vector boson in the Abelian Higgs model are equal. In addition, novel bound states of Higss and vector bosons trapped by the self-dual vortices at their core are found and investigated.
Ultraheavy Yukawa-bound states of fourth-generation at Large ...
Indian Academy of Sciences (India)
2012-10-05
Oct 5, 2012 ... Fourth-generation; Yukawa-bound states; Large Hadron Collider phenomenology. PACS Nos 14.65.Jk; 11.10.St; 13.85.Rm; 13.25.Jx. 1. Introduction. The fourth-generation (4G), if exists, can play a crucial role in electroweak symmetry breaking [1] and baryon asymmetry of the Universe [2] due to their strong ...
Zhu, Guo-Zhu; Huang, Dao-Ling; Wang, Lai-Sheng
2017-07-01
We report a photoelectron imaging and photodetachment study of cryogenically cooled 3-hydroxyphenoxide (3HOP) anions, m-HO(C6H4)O-. In a previous preliminary study, two conformations of the cold 3HOP anions with different dipole bound states were observed [D. L. Huang et al., J. Phys. Chem. Lett. 6, 2153 (2015)]. Five near-threshold vibrational resonances were revealed in the photodetachment spectrum from the dipole-bound excited states of the two conformations. Here, we report a more extensive investigation of the two conformers with observation of thirty above-threshold vibrational resonances in a wide spectral range between 18 850 and 19 920 cm-1 (˜1000 cm-1 above the detachment thresholds). By tuning the detachment laser to the vibrational resonances in the photodetachment spectrum, high-resolution conformation-selective resonant photoelectron images are obtained. Using information of the autodetachment channels and theoretical vibrational frequencies, we are able to assign the resonant peaks in the photodetachment spectrum: seventeen are assigned to vibrational levels of anti-3HOP, eight to syn-3HOP, and five to overlapping vibrational levels of both conformers. From the photodetachment spectrum and the conformation-selective resonant photoelectron spectra, we have obtained fourteen fundamental vibrational frequencies for the neutral syn- and anti-m-HO(C6H4)Oṡ radicals. The possibility to produce conformation-selected neutral beams using resonant photodetachment via dipole-bound excited states of anions is discussed.
Viscous dispersion effects on bound-state formation in falling liquid films
Pradas, Marc; Tseluiko, Dmitri; Kalliadasis, Serafim
2010-11-01
We examine the influence of viscous dispersion on the interaction of two-dimensional solitary pulses in falling liquid films at moderate Reynolds number. We make use of an averaged model that includes second-order viscous effects in the long-wave expansion. These effects play a dispersive role affecting primarily the shape of the capillary ripples in front of the solitary pulses. We show that different physical parameters, such as surface tension and viscosity, play a crucial role in the interaction between pulses giving rise eventually to the formation of bound states consisting of two or more pulses separated by well-defined distances and travelling at the same velocity. By developing a coherent-structures theory that assumes weak interaction between the pulses, we are able to theoretically predict the pulse-separation distances for which bound states are formed. It is shown that viscous dispersion significantly affects the distances at which bound states are observed. In all cases, there is very good agreement between the theory and computations of the fully nonlinear system.
Studies of photoionization processes from ground-state and excited-state atoms and molecules
Energy Technology Data Exchange (ETDEWEB)
Ederer, D.L.; Parr, A.C.; West, J.B.
1982-01-01
Recent triply-differential photoelectron spectroscopy experiments designed for the study of correlation effects in atoms and molecules are described. Final-state symmetry of the n=2 state of helium has been determined. The non-Franck-Condon behavior of vibrational branching ratios and large variations of the angular asymmetry parameter has been observed for shape resonances and autoionizing resonances in CO and other molecules. Recent observations of the photoionization of excited sodium atoms are also described.
Controlled state-to-state atom-exchange reaction in an ultracold atom-dimer mixture
Rui, Jun; Yang, Huan; Liu, Lan; Zhang, De-Chao; Liu, Ya-Xiong; Nan, Jue; Zhao, Bo; Pan, Jian-Wei
2016-01-01
Ultracold molecules offer remarkable opportunities to study chemical reactions at nearly zero temperature. Although significant progresses have been achieved in exploring ultracold bimolecular reactions, the investigations are usually limited to measurements of the overall loss rates of the reactants. Detection of the reaction products will shed new light on understanding the reaction mechanism and provide a unique opportunity to study the state-to-state reaction dynamics. Here we report on t...
High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED.
Ullmann, Johannes; Andelkovic, Zoran; Brandau, Carsten; Dax, Andreas; Geithner, Wolfgang; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Hannen, Volker; Kaufmann, Simon; König, Kristian; Litvinov, Yuri A; Lochmann, Matthias; Maaß, Bernhard; Meisner, Johann; Murböck, Tobias; Sánchez, Rodolfo; Schmidt, Matthias; Schmidt, Stefan; Steck, Markus; Stöhlker, Thomas; Thompson, Richard C; Trageser, Christian; Vollbrecht, Jonas; Weinheimer, Christian; Nörtershäuser, Wilfried
2017-05-16
Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209 Bi 82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209 Bi 82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.
High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED
Ullmann, Johannes; Andelkovic, Zoran; Brandau, Carsten; Dax, Andreas; Geithner, Wolfgang; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Hannen, Volker; Kaufmann, Simon; König, Kristian; Litvinov, Yuri A.; Lochmann, Matthias; Maaß, Bernhard; Meisner, Johann; Murböck, Tobias; Sánchez, Rodolfo; Schmidt, Matthias; Schmidt, Stefan; Steck, Markus; Stöhlker, Thomas; Thompson, Richard C.; Trageser, Christian; Vollbrecht, Jonas; Weinheimer, Christian; Nörtershäuser, Wilfried
2017-05-01
Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209Bi82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209Bi82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.
Excited State Atom-Ion Charge-Exchange
Li, Ming; Makrides, Constantinos; Petrov, Alexander; Kotochigova, Svetlana
2017-04-01
We theoretically investigate the exothermic charge-exchange reaction between an excited atom and a ground-state positive ion. In particular, we focus on MOT-excited Ca*(4s4p 1P) atoms colliding with ground-state Yb+ ions, which are under active study by the experimental group of E. Hudson at UCLA. Collisions between an excited atom and an ion are guided by two major contributions to the long-range interaction potentials, the induction C4 /R4 and charge-quadrupole C3 /R3 potentials, and their coupling by the electron-exchange interaction. Our model of these forces leads to close-coupling equations for multiple reaction channels. We find several avoided crossings between the potentials that couple to the nearby asymptotic limits of Yb*+Ca+, some of which can possibly provide large charge exchange rate coefficients above 10-10 cm3 / s. We acknowledge support from the US Army Research Office, MURI Grants W911NF-14-1-0378 and the US National Science Foundation, Grant PHY-1619788.
Gamow shell-model description of weakly bound and unbound nuclear states
Energy Technology Data Exchange (ETDEWEB)
Michel, N.; Nazarewicz, W. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Ploszajczak, M.; Rotureau, J. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DSM- NRS/IN2P3, BP 55027, F-14076 Caen Cedex 05 (France)
2004-12-01
Recently, the shell model in the complex k-plane (the so-called Gamow Shell Model) has been formulated using a complex Berggren ensemble representing bound single-particle states, single-particle resonances, and non-resonant continuum states. In this framework, we shall discuss binding energies and energy spectra of neutron-rich helium and lithium isotopes. The single-particle basis used is that of the Hartree-Fock potential generated self-consistently by the finite-range residual interaction. (Author) 21 refs., 5 tabs., 2 figs.
Bound states in a model of interaction of Dirac field with material plane
Directory of Open Access Journals (Sweden)
Pismak Yu. M.
2016-01-01
Full Text Available In the framework of the Symanzik approach model of the interaction of the Dirac spinor field with the material plane in the 3 + 1-dimensional space is constructed. The model contains eight real parameters characterizing the properties of the material plane. The general solution of the Euler-Lagrange equations of the model and dispersion equations for bound states are analyzed. It is shown that there is a choice of parameters of the model in which the connected states are characterized by dispersion law of a mass-less particle moving along the material plane with the dimensionless Fermi velocity not exceeding one.
Klein-Gordon lower bound to the semirelativistic ground-state energy
Energy Technology Data Exchange (ETDEWEB)
Hall, Richard L., E-mail: rhall@mathstat.concordia.c [Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Quebec, H3G 1M8 (Canada); Lucha, Wolfgang, E-mail: wolfgang.lucha@oeaw.ac.a [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria)
2010-04-19
For the class of attractive potentials V(r)<=0 which vanish at infinity, we prove that the ground-state energy E of the semirelativistic Hamiltonian H=sq root(m{sup 2}+p{sup 2})+V(r) is bounded below by the ground-state energy e of the corresponding Klein-Gordon problem (p{sup 2}+m{sup 2})phi=(V(r)-e){sup 2}phi. Detailed results are presented for the exponential and Woods-Saxon potentials.
Sarkar, Resham
In this thesis, we show first how to formulate the properties of all the collective states under various non-idealities, and use this formulation to understand the dynamics thereof. We show that the collective states corresponding to the absorption of a given number of photons can be visualized as an abstract, multi-dimensional rotation in the Hilbert space spanned by the ordered product states of individual atoms. We also consider the effect of treating the center of mass degree of freedom of the atoms quantum mechanically on the description of the collective states. In particular, we show that it is indeed possible to construct a generalized collective state, as needed for the COSAIN, when each atom is assumed to be in a localized wave packet. (Abstract shortened by ProQuest.).
Can one control systematic errors of QCD sum rule predictions for bound states?
Energy Technology Data Exchange (ETDEWEB)
Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Nuclear Physics Institute, Moscow State University, 119992 Moscow (Russian Federation)], E-mail: dmitri_melikhov@gmx.de; Simula, Silvano [INFN, Sezione di Roma III, Via della Vasca Navale 84, I-00146 Rome (Italy)
2007-11-29
We study the possibility to control systematic errors of the ground-state parameters obtained by Shifman-Vainshtein-Zakharov (SVZ) sum rules, making use of the harmonic-oscillator potential model as an example. In this case, one knows the exact solution for the polarization operator, which allows one to obtain both the OPE to any order and the parameters (masses and decay constants) of the bound states. We determine the parameters of the ground state making use of the standard procedures of the method of QCD sum rules, and compare the obtained results with the known exact values. We show that in the situation when the continuum contribution to the polarization operator is not known and is modelled by an effective continuum, the method of sum rules does not allow to control the systematic errors of the extracted ground-state parameters.
Super-atom molecular orbital excited states of fullerenes.
Johansson, J Olof; Bohl, Elvira; Campbell, Eleanor E B
2016-09-13
Super-atom molecular orbitals are orbitals that form diffuse hydrogenic excited electronic states of fullerenes with their electron density centred at the centre of the hollow carbon cage and a significant electron density inside the cage. This is a consequence of the high symmetry and hollow structure of the molecules and distinguishes them from typical low-lying molecular Rydberg states. This review summarizes the current experimental and theoretical studies related to these exotic excited electronic states with emphasis on femtosecond photoelectron spectroscopy experiments on gas-phase fullerenes.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'. © 2016 The Author(s).
Atomic Beam Correlations and the Quantum State of the Micromaser
Elmfors, P; Skagerstam, B S; Elmfors, Per; Lautrup, Benny; Skagerstam, Bo Sture
1997-01-01
Correlation measurements on atoms having passed through a micromaser can be used to infer properties of the quantum state of the radiation field in the cavity. Long- (or short)-range correlations in time are associated with super- (or sub)-Poissonian photon statistics. In some realistic experimental situations the long-range correlations may reach a magnitude of many times the decay time of the cavity. Our assertions are verified by comparing theoretical calculations with a high-precision Monte Carlo simulation of the micromaser system.
Raman cooling imaging: Detecting single atoms near their ground state of motion
Lester, Brian J.; Kaufman, Adam M.; Regal, Cindy A.
2014-01-01
We demonstrate imaging of neutral atoms via the light scattered during continuous Raman sideband cooling. We detect single atoms trapped in optical tweezers while maintaining a significant motional ground-state fraction. The techniques presented provide a framework for single-atom resolved imaging of a broad class of atomic species.
Hannestad, Steen
2005-11-25
At present, cosmology provides the nominally strongest constraint on the masses of standard model neutrinos. However, this constraint is extremely dependent on the nature of the dark energy component of the Universe. When the dark energy equation of state parameter is taken as a free (but constant) parameter, the neutrino mass bound is sigma m(v) energy is in the form of a cosmological constant. This has important consequences for future experiments aimed at the direct measurement of neutrino masses. We also discuss prospects for future cosmological measurements of neutrino masses.
Bound states of little strings and symmetric orbifold conformal field theories
Ahmed, Ambreen; Hohenegger, Stefan; Iqbal, Amer; Rey, Soo-Jong
2017-10-01
We study BPS bound states of little strings in a limit where they realize monopole strings in five dimensional gauge theories. The latter have gauge group U (M )N and arise from compactification of (1,0) little string theories of type AM -1×AN -1 . We find evidence that the partition function of a certain subclass of monopole strings of charge (k ,…,k ) (k ≥1 ) is expressible as the partition function of a symmetric orbifold sigma model, whose target space is precisely the symmetric product of the moduli space of monopoles with charge (1 ,…,1 ).
Shen, Ming; Gao, Jinsong; Ge, Lijuan
2015-01-01
We investigate the spatially optical solitons shedding from Airy beams and anomalous interactions of Airy beams in nonlocal nonlinear media by means of direct numerical simulations. Numerical results show that nonlocality has profound effects on the propagation dynamics of the solitons shedding from the Airy beam. It is also shown that the strong nonlocality can support periodic intensity distribution of Airy beams with opposite bending directions. Nonlocality also provides a long-range attractive force between Airy beams, leading to the formation of stable bound states of both in-phase and out-of-phase breathing Airy solitons which always repel in local media. PMID:25900878
Bound states of He(2 {sup 3}S)+He(2 {sup 3}P)
Energy Technology Data Exchange (ETDEWEB)
Cocks, D; Whittingham, I B [School of Engineering and Physical Sciences, James Cook University, Townsville, 4811 (Australia); Peach, G, E-mail: Daniel.Cocks@jcu.edu.a, E-mail: Ian.Whittingham@jcu.edu.a, E-mail: G.Peach@ucl.ac.u [Department of Physics and Astronomy, University College London, London, WC1E 6BT (United Kingdom)
2009-11-01
We report the results of coupled channel calculations of the bound states of the He(2 {sup 3}S{sub 1})+He(2 {sup 3}P{sub 0,1,2}) system using the recently available ab initio multi-configuration self-consistent field short range {sup 1,3,5}{Sigma}{sup +}{sub g,u} and {sup 1,3,5}{Pi}{sub g,u} potentials computed by Deguilhem et al. (J. Phys. B: At. Mol. Opt. Phys. 42 (2009) 015102) and present an analysis of the applicability of the single channel calculations of these authors.
A search for deeply-bound kaonic nuclear states at J-PARC
Directory of Open Access Journals (Sweden)
Sakaguchi A.
2010-04-01
Full Text Available The J-PARC E15 experiment will be performed to search for the simplest kaonic nuclear bound state, K− pp, by the in-ﬂight 3He(K−,n reaction. The exclusive measurement can be performed by a simultaneous measurement of the missing mass using the primary neutron and the invariant mass via the expected decay, K− pp → Λp → pπ− p. In this report, an overview of the experiment and the preparation status are presented.
Wedge-Local Fields in Integrable Models with Bound States II: Diagonal S-Matrix
Cadamuro, Daniela; Tanimoto, Yoh
2017-01-01
We construct candidates for observables in wedge-shaped regions for a class of 1+1-dimensional integrable quantum field theories with bound states whose S-matrix is diagonal, by extending our previous methods for scalar S-matrices. Examples include the Z(N)-Ising models, the A_N-affine Toda field theories and some S-matrices with CDD factors. We show that these candidate operators which are associated with elementary particles commute weakly on a dense domain. For the models with two species of particles, we can take a larger domain of weak commutativity and give an argument for the Reeh-Schlieder property.
Andreev reflection properties in a parallel mesoscopic circuit with Majorana bound states
Energy Technology Data Exchange (ETDEWEB)
Mu, Jin-Tao; Han, Yu [Physics Department, Liaoning University, Shenyang 110036 (China); Gong, Wei-Jiang, E-mail: gwj@mail.neu.edu.cn [College of Sciences, Northeastern University, Shenyang 110819 (China)
2017-03-15
We investigate the Andreev reflection in a parallel mesoscopic circuit with Majorana bound states (MBSs). It is found that in such a structure, the Andreev current can be manipulated in a highly efficient way, by the adjustment of bias voltage, dot levels, inter-MBS coupling, and the applied magnetic flux. Besides, the dot-MBS coupling manner is an important factor to modulate the Andreev current, because it influences the period of the conductance oscillation. By discussing the underlying quantum interference mechanism, the Andreev-reflection property is explained in detail. We believe that all the results can assist to understand the nontrivial role of the MBSs in driving the Andreev reflection.
Parente, Vincenzo; Campagnano, Gabriele; Giuliano, Domenico; Tagliacozzo, Arturo; Guinea, Francisco
2014-03-04
The scattering of Dirac electrons by topological defects could be one of the most relevant sources of resistance in graphene and at the boundary surfaces of a three-dimensional topological insulator (3D TI). In the long wavelength, continuous limit of the Dirac equation, the topological defect can be described as a distortion of the metric in curved space, which can be accounted for by a rotation of the Gamma matrices and by a spin connection inherited with the curvature. These features modify the scattering properties of the carriers. We discuss the self-energy of defect formation with this approach and the electron cross-section for intra-valley scattering at an edge dislocation in graphene, including corrections coming from the local stress. The cross-section contribution to the resistivity, ρ, is derived within the Boltzmann theory of transport. On the same lines, we discuss the scattering of a screw dislocation in a two-band 3D TI, like Bi1-xSbx, and we present the analytical simplified form of the wavefunction for gapless helical states bound at the defect. When a 3D TI is sandwiched between two even-parity superconductors, Dirac boundary states acquire superconductive correlations by proximity. In the presence of a magnetic vortex piercing the heterostructure, two Majorana states are localized at the two interfaces and bound to the vortex core. They have a half integer total angular momentum each, to match with the unitary orbital angular momentum of the vortex charge.
van Woerkom, David J.; Proutski, Alex; van Heck, Bernard; Bouman, Daniël; Väyrynen, Jukka I.; Glazman, Leonid I.; Krogstrup, Peter; Nygård, Jesper; Kouwenhoven, Leo P.; Geresdi, Attila
2017-09-01
The superconducting proximity effect in semiconductor nanowires has recently enabled the study of new superconducting architectures, such as gate-tunable superconducting qubits and multiterminal Josephson junctions. As opposed to their metallic counterparts, the electron density in semiconductor nanosystems is tunable by external electrostatic gates, providing a highly scalable and in situ variation of the device properties. In addition, semiconductors with large g-factor and spin-orbit coupling have been shown to give rise to exotic phenomena in superconductivity, such as φ0 Josephson junctions and the emergence of Majorana bound states. Here, we report microwave spectroscopy measurements that directly reveal the presence of Andreev bound states (ABS) in ballistic semiconductor channels. We show that the measured ABS spectra are the result of transport channels with gate-tunable, high transmission probabilities up to 0.9, which is required for gate-tunable Andreev qubits and beneficial for braiding schemes of Majorana states. For the first time, we detect excitations of a spin-split pair of ABS and observe symmetry-broken ABS, a direct consequence of the spin-orbit coupling in the semiconductor.
Ground-state structures of atomic metallic hydrogen.
McMahon, Jeffrey M; Ceperley, David M
2011-04-22
Ab initio random structure searching using density functional theory is used to determine the ground-state structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including proton zero-point motion within the harmonic approximation, we estimate that molecular hydrogen dissociates into a monatomic body-centered tetragonal structure near 500 GPa (r(s)=1.23) that remains stable to 1 TPa (r(s)=1.11). At higher pressures, hydrogen stabilizes in an …ABCABC… planar structure that is similar to the ground state of lithium, but with a different stacking sequence. With increasing pressure, this structure compresses to the face-centered cubic lattice near 3.5 TPa (r(s)=0.92).
Long-range interactions of excited He atoms with ground-state noble-gas atoms
Zhang, J.-Y.
2013-10-09
The dispersion coefficients C6, C8, and C10 for long-range interactions of He(n1,3S) and He(n1,3P), 2≤n≤10, with the ground-state noble-gas atoms Ne, Ar, Kr, and Xe are calculated by summing over the reduced matrix elements of multipole transition operators. The large-n expansions for the sums over the He oscillator strength divided by the corresponding transition energy are presented for these series. Using the expansions, the C6 coefficients for the systems involving He(131,3S) and He(131,3P) are calculated and found to be in good agreement with directly calculated values.
Ziegler, Klaus (Prof.)
1998-01-01
Lower bound for the fermi level density of states of a disordered D-wave superconductor in two dimensions / M. H. Hettler, P. J. Hirschfeld, K. Ziegler. - In: Physical review. B. 57. 1998. S. 10825-10830
Ratis, Yu L
2004-01-01
This paper substantiates a hypothesis that the natural fireball represents an area of space where the chain nuclear reaction of the bound state beta-decay of radioactive phosphorus nuclei takes place.
K− absorption on two nucleons and ppK− bound state search in the Σ0p final state
Directory of Open Access Journals (Sweden)
O. Vázquez Doce
2016-07-01
Full Text Available We report the measurement of K− absorption processes in the Σ0p final state and the first exclusive measurement of the two nucleon absorption (2NA with the KLOE detector. The 2NA process without further interactions is found to be 9% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK− bound state to the Σ0p final state. The yield of ppK−/Kstop− is found to be (0.044±0.009stat−0.005+0.004syst⋅10−2 but its statistical significance based on an F-test is only 1σ.
Extended Eckart Theorem and New Variation Method for Excited States of Atoms
Xiong, Zhuang; Bacalis, N C; Zhou, Qin
2016-01-01
We extend the Eckart theorem, from the ground state to excited statew, which introduces an energy augmentation to the variation criterion for excited states. It is shown that the energy of a very good excited state trial function can be slightly lower than the exact eigenvalue. Further, the energy calculated by the trial excited state wave function, which is the closest to the exact eigenstate through Gram-Schmidt orthonormalization to a ground state approximant, is lower than the exact eigenvalue as well. In order to avoid the variation restrictions inherent in the upper bound variation theory based on Hylleraas, Undheim, and McDonald [HUM] and Eckart Theorem, we have proposed a new variation functional Omega-n and proved that it has a local minimum at the eigenstates, which allows approaching the eigenstate unlimitedly by variation of the trial wave function. As an example, we calculated the energy and the radial expectation values of Triplet-S(even) Helium atom by the new variation functional, and by HUM a...
Bernon, S.; Vanderbruggen, T.; Kohlhaas, R.; Bertoldi, A.; Landragin, A.; Bouyer, P.
2011-06-01
We report on a novel experiment to generate non-classical atomic states via quantum non-demolition (QND) measurements on cold atomic samples prepared in a high-finesse ring cavity. The heterodyne technique developed for QND detection exhibits an optical shot-noise limited behavior for local oscillator optical power of a few hundred μW, and a detection bandwidth of several GHz. This detection tool is used in a single pass to follow non-destructively the internal state evolution of an atomic sample when subjected to Rabi oscillations or a spin-echo interferometric sequence.
Energy Technology Data Exchange (ETDEWEB)
Bernon, S; Vanderbruggen, T; Kohlhaas, R; Bertoldi, A; Bouyer, P [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS and Universite Paris-Sud Campus Polytechnique, RD 128, F-91127 Palaiseau cedex (France); Landragin, A, E-mail: simon.bernon@institutoptique.fr [LNE-SYRTE, Observatoire de Paris, CNRS and UPMC 61 avenue de l' Observatoire, F-75014 Paris (France)
2011-06-15
We report on a novel experiment to generate non-classical atomic states via quantum non-demolition (QND) measurements on cold atomic samples prepared in a high-finesse ring cavity. The heterodyne technique developed for QND detection exhibits an optical shot-noise limited behavior for local oscillator optical power of a few hundred {mu}W, and a detection bandwidth of several GHz. This detection tool is used in a single pass to follow non-destructively the internal state evolution of an atomic sample when subjected to Rabi oscillations or a spin-echo interferometric sequence.
Three-Nucleon Bound States and the Wigner-SU(4) Limit
Vanasse, Jared; Phillips, Daniel R.
2017-03-01
We examine the extent to which the properties of three-nucleon bound states are well-reproduced in the limit that nuclear forces satisfy Wigner's SU(4) (spin-isospin) symmetry. To do this we compute the charge radii up to next-to-leading order (NLO) in an effective field theory that is an expansion in powers of R/ a, with R the range of the nuclear force and a the nucleon-nucleon (N N) scattering lengths. In the Wigner-SU(4) limit, the triton and helium-3 point charge radii are equal. At NLO in the range expansion both are 1.66 fm. Adding the first-order corrections due to the breaking of Wigner symmetry in the N N scattering lengths gives a ^3{H} point charge radius of 1.58 fm, which is remarkably close to the experimental number, 1.5978± 0.040 fm (Angeli and Marinova in At Data Nucl Data Tables 99:69-95, 2013). For the ^3{He} point charge radius we find 1.70 fm, about 4% away from the experimental value of 1.77527± 0.0054 fm (Angeli and Marinova 2013). We also examine the Faddeev components that enter the tri-nucleon wave function and find that an expansion of them in powers of the symmetry-breaking parameter converges rapidly. Wigner's SU(4) symmetry is thus a useful starting point for understanding tri-nucleon bound-state properties.
Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers
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A. Komarov
2012-01-01
Full Text Available We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.
Anomalous thermoelectric properties in double quantum dots coupled with Majorana bound states
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Yi-Jie Zheng
2016-12-01
Full Text Available We discuss the transport properties of thermal electrons in double quantum dots that are coupled with Majorana bound states (MBSs corresponding to two model systems with T-type structure and series connection structure. It has been found that the thermoelectric figure of merit ZT in these model systems is suppressed when we consider the effects of the Majorana bound states. Here, ZT=GS2Tκ, where G is the electric conductance, S is the thermopower, T is the temperature and κ is the thermal conductance. The sign of the thermopower S changes from negative to positive when the energy levels of the quantum dots are less than μ while the sign of the thermopower S changes from positive to negative when the energy levels of the quantum dots are above μ in the model system of T-type structure, where μ is the chemical potential. As a result, the figure of merit ZT first decreases and then increases as the temperature kBT increases. This behavior is different from what is seen in the general quantum dot structure without MBSs. It is interesting to show that in the series connection structure, the thermopower S and ZT are robustness and do not vary with changes in εM when |εd|<λ, even if κ changes with εM.
Transient Development of Excited State Densities in Atomic Helium Plasmas
1976-03-01
n s t i t u e n t s caus ing a t . ransfer to bound e l e c t r o n s b e t w e e n the l o w - l y i n g s t a t e s and u p p e r s t a t...r y and t h e s e a r e d i s c u s s e d in de ta i l . 4.1 ENERGY LEVELS The h e l i u m e n e r g y l e v e l s u s e d in th i s s...e t h e n d e t e r m i n e d f r o m t h e s e v a l u e s . 4] AEDC-TR-76-5 Table 1. Helium Energy Lwel$ State g E (i/cm) State g E (i
Localization of cold atoms in state-dependent optical lattices via a Rabi Pulse.
Horstmann, Birger; Dürr, Stephan; Roscilde, Tommaso
2010-10-15
We propose a novel realization of Anderson localization in nonequilibrium states of ultracold atoms in an optical lattice. A Rabi pulse transfers part of the population to a different internal state with infinite effective mass. These frozen atoms create a quantum superposition of different disorder potentials, localizing the mobile atoms. For weakly interacting mobile atoms, Anderson localization is obtained. The localization length increases with increasing disorder and decreasing interaction strength, contrary to the expectation for equilibrium localization.
The Unique Hoyle State of the Carbon Atom
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Thorvaldsen, Steinar
2015-05-01
Full Text Available The famous astronomer Fred Hoyle (1915-2001 started his research career as an atheist. Hoyle’s most important contribution to astrophysics is the theory of nucleosynthesis, i.e. the idea that chemical elements such as carbon can form in stars on the basis of hydrogen and helium. Essentially here was his prediction that the carbon core has a state with a specific energy which is precisely adapted to the basic fusion process. This result was one of the most important breakthroughs in modern astrophysics, and the so called Hoyle state has become a cornerstone for state-ofthe- art nuclear theory. The calculations he made, eventually revealed a fine-tuning of the universe. Hoyle’s work in this area supported the anthropic principle that the universe was fine-tuned so that intelligent life would be possible. It is said that what really made him conclude that creation demanded intelligence, were his calculations of the special properties of the carbon atom. This shook his atheism fundamentally [1, p. 57]. In this paper we describe this discovery.
Directory of Open Access Journals (Sweden)
Vincenzo Parente
2014-03-01
Full Text Available The scattering of Dirac electrons by topological defects could be one of the most relevant sources of resistance in graphene and at the boundary surfaces of a three-dimensional topological insulator (3D TI. In the long wavelength, continuous limit of the Dirac equation, the topological defect can be described as a distortion of the metric in curved space, which can be accounted for by a rotation of the Gamma matrices and by a spin connection inherited with the curvature. These features modify the scattering properties of the carriers. We discuss the self-energy of defect formation with this approach and the electron cross-section for intra-valley scattering at an edge dislocation in graphene, including corrections coming from the local stress. The cross-section contribution to the resistivity, ρ, is derived within the Boltzmann theory of transport. On the same lines, we discuss the scattering of a screw dislocation in a two-band 3D TI, like Bi1-xSbx, and we present the analytical simplified form of the wavefunction for gapless helical states bound at the defect. When a 3D TI is sandwiched between two even-parity superconductors, Dirac boundary states acquire superconductive correlations by proximity. In the presence of a magnetic vortex piercing the heterostructure, two Majorana states are localized at the two interfaces and bound to the vortex core. They have a half integer total angular momentum each, to match with the unitary orbital angular momentum of the vortex charge.
Energy Technology Data Exchange (ETDEWEB)
Datta, Nilanjana, E-mail: n.datta@statslab.cam.ac.uk [Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Hsieh, Min-Hsiu, E-mail: Min-Hsiu.Hsieh@uts.edu.au [Centre for Quantum Computation and Intelligent Systems, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007 (Australia); Oppenheim, Jonathan, E-mail: j.oppenheim@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Department of Computer Science and Centre for Quantum Technologies, National University of Singapore, Singapore 119615 (Singapore)
2016-05-15
State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement. We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol of coherent state merging as a primitive.
Bound states of water in gelatin discriminated by near-infrared spectroscopy
Otsuka, Yukiko; Shirakashi, Ryo; Hirakawa, Kazuhiko
2017-11-01
By near-infrared spectroscopy, we classified water molecules in hydrated gelatin membranes in a drying process. Absorbance spectra in the frequency range of 4500–5500 cm‑1 were resolved into three peaks, S0, S1, and S2, that correspond to water molecules with different hydrogen bond states. From the areas of the absorbance peaks as a function of the water content of gelatin, together with the information on the freezing properties of water measured by differential scanning calorimetry, we found that, when the water content is less than 20%, free water disappears and only weakly and strongly bound waters remain. We also found that the weakly bound water consists of S0, S1, and S2 water molecules with a simple composition of \\text{S}0:\\text{S}1:\\text{S}2 ≈ 1:2:0. Using this information, most of the freezable water was determined to be free water. Our classification provides a simple method of estimating the retention and freezing properties of processed foods or drugs by infrared spectroscopy.
The effect of bound states on X-ray Thomson scattering for partially ionized plasmas
Nilsen, J; Cheng, K T
2013-01-01
X-ray Thomson scattering is being developed as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such as those used in inertial confinement fusion. X-ray laser sources have always been of interest because of the need to have a bright monochromatic x-ray source to overcome plasma emission and eliminate other lines in the background that complicate the analysis. With the advent of the xray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) and other facilities coming online worldwide, we now have such a source available in the keV regime. Most Thomson scattering codes used to model experimental data greatly simplify or neglect the contributions of the bound electrons to the scattered intensity. In this work we take the existing models of Thomson scattering that include elastic ion-ion scattering and inelastic electron-electron scattering and add the contribution of bound electrons in the partially ionized plasmas. To date, most exp...
Diabetes Among United States-Bound Adult Refugees, 2009-2014.
Benoit, Stephen R; Gregg, Edward W; Zhou, Weigong; Painter, John A
2016-12-01
We reported diabetes prevalence among all US-bound adult refugees and assessed factors associated with disease. We analyzed overseas medical evaluations of US-bound refugees from 2009 through 2014 by using CDC's Electronic Disease Notification System. We identified refugees with diabetes by searching for diabetes-related keywords and medications in examination forms with text-parsing techniques. Age-adjusted prevalence rates were reported and factors associated with diabetes were assessed by using logistic regression. Of 248,850 refugees aged ≥18 years examined over 5 years, 5767 (2.3 %) had diabetes. Iraqis had the highest crude (5.1 %) and age-adjusted (8.9 %) prevalence of disease. Higher age group and body mass index were associated with diabetes in all regions. Diabetes prevalence varied by refugee nationality. Although the absolute rates were lower than rates in the United States, the prevalence is still concerning given the younger age of the population and their need for health services upon resettlement.
Kalchmair, Stefan; Gansch, Roman; Genevet, Patrice; Zederbauer, Tobias; MacFarland, Donald; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried; Capasso, Federico; Loncar, Marko
2016-04-01
Photonic crystal slabs have been subject to research for more than a decade, yet the existence of bound states in the radiation continuum (BICs) in photonic crystals has been reported only recently [1]. A BIC is formed when the radiation from all possible channels interferes destructively, causing the overall radiation to vanish. In photonic crystals, BICs are the result of accidental phase matching between incident, reflected and in-plane waves at seemingly random wave vectors [2]. While BICs in photonic crystals have been discussed previously using reflection measurements, we reports for the first time in-situ measurements of the bound states in the continuum in photonic crystal slabs. By embedding a photodetector into a photonic crystal slab we were able to directly observe optical BICs. The photonic crystal slabs are processed from a GaAs/AlGaAs quantum wells heterostructure, providing intersubband absorption in the mid-infrared wavelength range. The generated photocurrent is collected via doped contact layers on top and bottom of the suspended photonic crystal slab. We were mapping out the photonic band structure by rotating the device and by acquiring photocurrent spectra every 5°. Our measured photonic bandstructure revealed several BICs, which was confirmed with a rigorously coupled-wave analysis simulation. Since coupling to external fields is suppressed, the photocurrent measured by the photodetector vanishes at the BIC wave vector. To confirm the relation between the measured photocurrent and the Q-factor we used temporal coupled mode theory, which yielded an inverse proportional relation between the photocurrent and the out-coupling loss from the photonic crystal. Implementing a plane wave expansion simulation allowed us to identify the corresponding photonic crystal modes. The ability to directly measure the field intensity inside the photonic crystal presents an important milestone towards integrated opto-electronic BIC devices. Potential
Arzano, M.; Kowalski-Glikman, J.; Walkus, A.
2010-01-01
High-sensitivity measurements in atomic spectroscopy were recently used by Amelino- Camelia et al. (Phys. Rev. Lett., 103 (2009) 171302) to constraint the form of possible modifications of the energy-momentum dispersion relation resulting from Lorentz invariance violation (LIV). In this letter we
Directly measuring the concurrence of two-atom state via detecting coherent lights
Chen, Li; Yang, Ming; Zhang, Li-Hua; Cao, Zhuo-Liang
2017-11-01
Concurrence is an important parameter for quantifying quantum entanglement, but usually the state tomography must be determined before quantification. In this paper we propose a scheme, based on cavity-assisted atom–light interaction, to measure the concurrence of two-atom pure states and the Collins–Gisin state directly, without tomography. The concurrence of atomic states is encoded in the output coherent optical beams after interacting with cavities and the atoms therein, so the results of detection applied to the output coherent optical beams provide the concurrence data of the atomic states. This scheme provides an alternative method for directly measuring atomic entanglement by detecting coherent light, rather than measuring the atomic systems, which thus greatly simplifies the realization complexity of the direct measurement of atomic entanglement. In addition, as the cavity-assisted atom–light interaction used here is robust and scalable in realistic applications, the current scheme may be realized in the near future.
Scheme for teleportation of entangled states without Bell-state measurement by using one atom
Energy Technology Data Exchange (ETDEWEB)
Qiang Wenchao; Zhang Lei; Zhang Aiping [Faculty of Science, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Dong Shihai, E-mail: qwcqj@163.com [Departamento de Fisica, Esc. Sup de Fisica y Matematicas, Instituto Politecnico Nacional, Edificio 9, Unidad Profesional Adolfo Lopez Mateos, Mexico, DF 07738 (Mexico)
2011-07-01
We propose a scheme for approximately and conditionally teleporting an entanglement of zero- and one-photon states from a cavity with left- and right-polarized modes to another similar one, with a fidelity exceeding 99%. Instead of using the Bell-state measurement, only one atom is used in our scheme. The time spent, the success probability and the feasibility of the proposed scheme are also discussed.
Hyperon-nucleon bound states and electroproduction of strangeness on light nuclei.
Energy Technology Data Exchange (ETDEWEB)
Dohrmann, F.; Abbott, D.; Ahmidouch, A.; Ambrozewicz, P.; Armstrong, C. S.; Arrington, J.; Bailey, K.; Cummings, W. J.; Gao, H.; Garrow, K.; Geesaman, D. F.; Hafidi, K.; Hansen, J. O.; Jackson, H. E.; Mueller, B.; O' Neill, T. G.; Potterveld, D.; Reimer, P. E.; Reinhold, J.; Zeidman, B.
2002-06-25
The A(e,e{prime}K{sup +})Y X reaction has been investigated in Hall C at Jefferson Lab. Data were taken for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at a beam energy of 3.245 GeV for {sup 1}H, {sup 2}H, {sup 3}He and {sup 4}He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations including {Lambda}, {Sigma}{sup 0}, {Sigma}{sup -} hyperon production. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for {Lambda}-hypernuclear bound states is seen for {sup 3,4}He targets.
Bound state properties of ABC-stacked trilayer graphene quantum dots.
Xiong, Haonan; Jiang, Wentao; Song, Yipu; Duan, Luming
2017-06-01
The few-layer graphene quantum dot provides a promising platform for quantum computing with both spin and valley degrees of freedom. Gate-defined quantum dots in particular can avoid noise from edge disorders. In connection with the recent experimental efforts (Song et al 2016 Nano Lett. 16 6245), we investigate the bound state properties of trilayer graphene (TLG) quantum dots (QDs) through numerical simulations. We show that the valley degeneracy can be lifted by breaking the time reversal symmetry through the application of a perpendicular magnetic field. The spectrum under such a potential exhibits a transition from one group of Landau levels to another group, which can be understood analytically through perturbation theory. Our results provide insight into the transport property of TLG QDs, with possible applications to study of spin qubits and valleytronics in TLG QDs.
Quantum chromodynamics and the dynamics of hadrons. [Review, bound state, perturbation theory
Energy Technology Data Exchange (ETDEWEB)
Brodsky, S.J.
1979-03-01
The application of perturbative quantum chromodynamics to the dynamics of hadrons at short distance is reviewed, with particular emphasis on the role of the hadronic bound state. A number of new applications are discussed, including the modification to QCD scaling violations in structure functions due to hadronic binding; a discussion of coherence and binding corrections to the gluon and sea-quark distributions; QCD radiative corrections to dimensional counting rules for exclusive processes and hadronic form factors at large momentum transfer; generalized counting rules for inclusive processes; the special role of photon-induced reactions in QCD, especially applications to jet production in photon-photon collisions, and photon production at large transverse momentum. Also presented is a short review of the central problems in large P/sub T/ hadronic reactions and the distinguishing characteristics of gluon and quark jets. 163 references.
Bound state properties of ABC-stacked trilayer graphene quantum dots
Xiong, Haonan; Jiang, Wentao; Song, Yipu; Duan, Luming
2017-06-01
The few-layer graphene quantum dot provides a promising platform for quantum computing with both spin and valley degrees of freedom. Gate-defined quantum dots in particular can avoid noise from edge disorders. In connection with the recent experimental efforts (Song et al 2016 Nano Lett. 16 6245), we investigate the bound state properties of trilayer graphene (TLG) quantum dots (QDs) through numerical simulations. We show that the valley degeneracy can be lifted by breaking the time reversal symmetry through the application of a perpendicular magnetic field. The spectrum under such a potential exhibits a transition from one group of Landau levels to another group, which can be understood analytically through perturbation theory. Our results provide insight into the transport property of TLG QDs, with possible applications to study of spin qubits and valleytronics in TLG QDs.
Meson-nucleus potentials and the search for meson-nucleus bound states
Metag, V.; Nanova, M.; Paryev, E. Ya.
2017-11-01
Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.
Bound states of a light atom and two heavy dipoles in two dimensions
DEFF Research Database (Denmark)
Rosa, D. S.; Bellotti, F. F.; Jensen, Aksel Stenholm
2016-01-01
We study a three-body system, formed by a light particle and two identical heavy dipoles, in two dimensions in the Born-Oppenheimer approximation. We present the analytic light-particle wave function resulting from an attractive zero-range potential between the light and each of the heavy particles....... It expresses the large-distance universal properties which must be reproduced by all realistic short-range interactions. We calculate the three-body spectrum for zero heavy-heavy interaction as a function of light to heavy mass ratio. We discuss the relatively small deviations from Coulomb estimates...
Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid
Yu, Deshui; Valado, María Martínez; Hufnagel, Christoph; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer
2016-01-01
Hybrids consisting of macroscopic superconducting circuits and microscopic components, such as atoms and spins, have the potential of transmitting an arbitrary state between different quantum species, leading to the prospective of high-speed operation and long-time storage of quantum information. Here we propose a novel hybrid structure, where a neutral-atom qubit directly interfaces with a superconducting charge qubit, to implement the qubit-state transmission. The highly-excited Rydberg atom located inside the gate capacitor strongly affects the behavior of Cooper pairs in the box while the atom in the ground state hardly interferes with the superconducting device. In addition, the DC Stark shift of the atomic states significantly depends on the charge-qubit states. By means of the standard spectroscopic techniques and sweeping the gate voltage bias, we show how to transfer an arbitrary quantum state from the superconducting device to the atom and vice versa. PMID:27922087
Existence of Majorana bound states near impurities in the case of a small superconducting gap
Chuburin, Yu. P.
2017-05-01
We consider the edge states of a 2D topological insulator in the presence of the Zeeman field and in proximity to a s-wave superconductor. We analytically show that two linearly independent Majorana bound states (MBSs) can appear near the impurity located in a small region in which both the pairing parameter Δ and the Zeeman field M may be changed. We find two conditions for the existence of the MBSs: firstly, | Δ | ≈ | M | , ie, the superconducting gap in the spectrum should be sufficiently small; secondly, the absolute value of the average w of the impurity potential should have a certain value; the last condition is necessary. The equation | Δ | = | M | determines the boundary of the topological phase of the system, thus the system as a whole must be close to this boundary in relation to the parameters. If the same is true for the impurity region, then the second condition has the form w ≈ ± v / 2 where v is the edge states velocity. In this case, the electron transmission probability is equal to 1 for energies close to zero.
Bound states in nanoscale graphene quantum dots in a continuous graphene sheet
Qiao, Jia-Bin; Jiang, Hua; Liu, Haiwen; Yang, Hong; Yang, Ning; Qiao, Kai-Yao; He, Lin
2017-02-01
Considerable efforts have been made to trap massless Dirac fermions in a graphene monolayer, but only quasibound states have been realized in continuous graphene sheets up to now. Here, we demonstrate the realization of bound states in nanoscale graphene quantum dots (GQDs) in a continuous graphene sheet. The GQDs are electronically isolated from the surrounding continuous graphene sheet by circular boundaries, which are generated by strong coupling between graphene and the substrate. By using scanning tunneling microscopy (STM), we observe single-electron charging states of the GQDs, seen as Coulomb oscillations in the tunneling conductance. The evolution of single-electron tunneling of the GQDs between the Coulomb blockade regime and the Coulomb staircase regime is observed by tuning the STM tip-sample distances. Spatial maps of the local electronic densities reveal concentric rings inside the GQDs with each ring corresponding to a single Coulomb oscillation of the tunneling spectra. These results indicate explicitly that the electrons are completely trapped inside the nanoscale GQDs.
Directory of Open Access Journals (Sweden)
Sanchari Banerjee
2016-07-01
Full Text Available Macromolecular crystals for X-ray diffraction studies are typically grown in vitro from pure and homogeneous samples; however, there are examples of protein crystals that have been identified in vivo. Recent developments in micro-crystallography techniques and the advent of X-ray free-electron lasers have allowed the determination of several protein structures from crystals grown in cellulo. Here, an atomic resolution (1.2 Å crystal structure is reported of heterogeneous milk proteins grown inside a living organism in their functional niche. These in vivo-grown crystals were isolated from the midgut of an embryo within the only known viviparous cockroach, Diploptera punctata. The milk proteins crystallized in space group P1, and a structure was determined by anomalous dispersion from the native S atoms. The data revealed glycosylated proteins that adopt a lipocalin fold, bind lipids and organize to form a tightly packed crystalline lattice. A single crystal is estimated to contain more than three times the energy of an equivalent mass of dairy milk. This unique storage form of nourishment for developing embryos allows access to a constant supply of complete nutrients. Notably, the crystalline cockroach-milk proteins are highly heterogeneous with respect to amino-acid sequence, glycosylation and bound fatty-acid composition. These data present a unique example of protein heterogeneity within a single in vivo-grown crystal of a natural protein in its native environment at atomic resolution.
Measuring the charge state of an adatom with noncontact atomic force microscopy
Gross, L.; Mohn, F.; Liljeroth, P.|info:eu-repo/dai/nl/314007423; Repp, J.; Meyer, G.; Giessibl, F.J.
2009-01-01
Charge states of atoms can be investigated with scanning tunneling microscopy, but this method requires a conducting substrate. We investigated the charge-switching of individual adsorbed gold and silver atoms (adatoms) on ultrathin NaCl films on Cu(111) using a qPlus tuning fork atomic force
High-fidelity Rydberg quantum gate via a two-atom dark state
Petrosyan, David; Motzoi, Felix; Saffman, Mark; Mølmer, Klaus
2017-10-01
We propose a two-qubit gate for neutral atoms in which one of the logical state components adiabatically follows a two-atom dark state formed by the laser coupling to a Rydberg state and a strong resonant dipole-dipole exchange interaction between two Rydberg excited atoms. Our gate exhibits optimal scaling of the intrinsic error probability E ∝(Bτ ) -1 with the interatomic interaction strength B and the Rydberg state lifetime τ . Moreover, the gate is resilient to variations in the interaction strength, and even for finite probability of double Rydberg excitation the gate does not excite atomic motion and experiences no decoherence due to internal-translational entanglement.
Khan, Mayukh Nilay; Teo, Jeffrey C. Y.; Hughes, Taylor L.; Vishveshwara, Smitha
2017-05-01
flip and charge conjugation are considered, they lead to Z2 n +1 parafermions in Laughlin 1 /(2 n +1 ) states. Our formalism also reproduces known results such as Majorana/parafermionic bound states at superconducting domain walls of topological/fractional Chern insulators when twist defects are constructed based on charge conjugation symmetry. Finally, we briefly describe more exotic twist liquid phases obtained by gauging the AS where the twist defects become deconfined anyonic excitations.
Johnson, T H; Yuan, Y; Bao, W; Clark, S R; Foot, C; Jaksch, D
2016-06-17
We investigate cold bosonic impurity atoms trapped in a vortex lattice formed by condensed bosons of another species. We describe the dynamics of the impurities by a bosonic Hubbard model containing occupation-dependent parameters to capture the effects of strong impurity-impurity interactions. These include both a repulsive direct interaction and an attractive effective interaction mediated by the Bose-Einstein condensate. The occupation dependence of these two competing interactions drastically affects the Hubbard model phase diagram, including causing the disappearance of some Mott lobes.
Energy Technology Data Exchange (ETDEWEB)
Nagasaka, Masanari; Hatsui, Takaki; Setoyama, Hiroyuki; Ruehl, Eckart [Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan); Kosugi, Nobuhiro, E-mail: kosugi@ims.ac.j [Institute for Molecular Science, Myodaiji, Okazaki 444-8585 (Japan)
2011-01-15
Surface-site resolved Kr 3d{sub 5/2}{sup -1}5p and 3d{sub 5/2}{sup -1}6p and Xe 4d{sub 5/2}{sup -1}6p and 4d{sub 5/2}{sup -1}7p Rydberg excited states in small van der Waals Kr and Xe clusters with a mean size of
Fano effect and Andreev bound states in a hybrid superconductor–ferromagnetic nanostructure
Energy Technology Data Exchange (ETDEWEB)
Siqueira, E.C., E-mail: ezcostta@gmail.com [Departamento de Física, Universidade Tecnológica Federal do Paraná – UTFPR, 84016210, Ponta Grossa, PR (Brazil); Orellana, P.A. [Departamento de Física, Universidad Técnica Federico Santa Maria, Av. Vicuña Mackenna 3939, Santiago (Chile); Cestari, R.C. [Departamento de Física e Química, Universidade Estadual Paulista – UNESP, 15385-000, Ilha Solteira, SP (Brazil); Figueira, M.S. [Instituto de Física, Universidade Federal Fluminense, 24210-340, Niterói, RJ (Brazil); Cabrera, G.G. [Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas – UNICAMP, Campinas 13083-859, SP (Brazil)
2015-10-16
In this work, it is considered a hybrid nanostructure composed by a quantum dot coupled to two ferromagnetic leads and a superconductor lead. It is shown that the zero-bias transmittance for the co-tunneling between the ferromagnetic leads presents Fano anti-resonances due to the destructive interference between the two spin channels mixing by the relative orientation of the magnetizations in the leads. When the superconductor is coupled to the system, electron–hole correlations between different spin states lead to a resonance in the place of the dip appearing in the transmittance. Such an effect is accompanied by two Fano anti-resonances explained by a “leakage” of conduction channels from the co-tunneling to the Andreev transport. In the non-equilibrium regime, correlations within the quantum dot introduce a dependence of the resonance condition on the finite bias applied to the ferromagnetic leads. However, it is still possible to observe signatures of the same interference effect in the electrical current. - Highlights: • We have studied an hybrid nanostructure composed by quantum dot coupled to a superconductor and two ferromagnets. • The interplay between spin polarization and Andreev bound states leads to a Fano-like effect. • The Fano-like effect manifests as a resonance in the transmittance for the transport between the ferromagnets.
Electron-electron bound states in Maxwell-Chern-Simons-Proca QED sub 3
Belich, H; Ferreira, M M J; Helayel-Neto, J A
2002-01-01
We start from a parity-breaking MCS QED sub 3 model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e sup - e sup - - bound state. Three expressions V sub e sub f sub f subarrow down subarrow down, V sub e sub f sub f subarrow down subarrow up, V sub e sub f sub f subarrow down subarrow down) are obtained according to the polarization state of the scattered electrons. In an energy scale compatible with condensed matter electronic excitations, these potentials become degenerated. The resulting potential is implemented in the Schroedinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10 - 30 Angstrom are possible indications that the MCS-QED sub 3 model adopted may be suitable to address an eventual case of e sup - e sup - pairing in the presence o...
Electroweak-charged bound states as LHC probes of hidden forces
Li, Lingfeng; Salvioni, Ennio; Tsai, Yuhsin; Zheng, Rui
2018-01-01
We explore the LHC reach on beyond-the-standard model (BSM) particles X associated with a new strong force in a hidden sector. We focus on the motivated scenario where the SM and hidden sectors are connected by fermionic mediators ψ+,0 that carry SM electroweak charges. The most promising signal is the Drell-Yan production of a ψ±ψ¯ 0 pair, which forms an electrically charged vector bound state ϒ± due to the hidden force and later undergoes resonant annihilation into W±X . We analyze this final state in detail in the cases where X is a real scalar ϕ that decays to b b ¯, or a dark photon γd that decays to dileptons. For prompt X decays, we show that the corresponding signatures can be efficiently probed by extending the existing ATLAS and CMS diboson searches to include heavy resonance decays into BSM particles. For long-lived X , we propose new searches where the requirement of a prompt hard lepton originating from the W boson ensures triggering and essentially removes any SM backgrounds. To illustrate the potential of our results, we interpret them within two explicit models that contain strong hidden forces and electroweak-charged mediators, namely λ -supersymmetry (SUSY) and non-SUSY ultraviolet extensions of the twin Higgs model. The resonant nature of the signals allows for the reconstruction of the mass of both ϒ± and X , thus providing a wealth of information about the hidden sector.
Znojil, Miloslav
2017-07-01
The phenomenon of the birth of an isolated quantum bound state at the lower edge of the continuum is studied for a particle moving along a discrete real line of coordinates x ∈Z . The motion is controlled by a weakly nonlocal 2 J -parametric external potential V which is non-Hermitian but P T symmetric. The model is found exactly solvable. The bound states are interpreted as Sturmians. Their closed-form definitions are presented and discussed up to J =7 .
Energy Technology Data Exchange (ETDEWEB)
Sturm, Sven
2012-09-06
This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike {sup 28}Si{sup 13+}. The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10{sup -11}, which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.
Energy Technology Data Exchange (ETDEWEB)
Boutin, D.
2005-08-01
The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. {sup 163}Dy, became unstable. Also a drastic modification of the half-life of bare {sup 187}Re, from 4.12(2) x 10{sup 10} years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio {beta}{sub b}/{beta}{sub c} could also be evaluated for the first time. {sup 207}Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the {beta}{sub b} probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of {sup 207}Tl{sup 81+} have been investigated at the GSI accelerator facility in two separate experiments. For the first time {beta}-decay where the electron could go either to a bound state (atomic orbitals) and lead to {sup 207}Pb{sup 81+} as a daughter nuclide, or to a continuum state and lead to {sup 207}Pb{sup 82+}, has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for {sup 207}Tl{sup 81+}, was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching {beta}{sub b}/{beta}{sub c}=0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of {sup
Automated extraction of single H atoms with STM: tip state dependency
Møller, Morten; Jarvis, Samuel P.; Guérinet, Laurent; Sharp, Peter; Woolley, Richard; Rahe, Philipp; Moriarty, Philip
2017-02-01
The atomistic structure of the tip apex plays a crucial role in performing reliable atomic-scale surface and adsorbate manipulation using scanning probe techniques. We have developed an automated extraction routine for controlled removal of single hydrogen atoms from the H:Si(100) surface. The set of atomic extraction protocols detect a variety of desorption events during scanning tunneling microscope (STM)-induced modification of the hydrogen-passivated surface. The influence of the tip state on the probability for hydrogen removal was examined by comparing the desorption efficiency for various classifications of STM topographs (rows, dimers, atoms, etc). We find that dimer-row-resolving tip apices extract hydrogen atoms most readily and reliably (and with least spurious desorption), while tip states which provide atomic resolution counter-intuitively have a lower probability for single H atom removal.
Bound states in the continuum and polarization singularities in periodic arrays of dielectric rods
Bulgakov, Evgeny N.; Maksimov, Dmitrii N.
2017-12-01
We consider optical bound states in the continuum (BICs) in periodic arrays of dielectric rods. The full classification of BICs in the above system is provided, including the modes propagating along the axes of the rods and bidirectional BICs propagating both along the axes of the rods and the axis of periodicity. It is shown that the leaky zones supporting the BICs generally have elliptically polarized far-field radiation patterns, with the polarization ellipses collapsing on approach to the BICs in momentum space. That allowed us to apply the concept of polarization singularities and demonstrate that the BICs possess a topological charge defined as the winding number of the polarization direction [Phys. Rev. Lett. 113, 257401 (2014), 10.1103/PhysRevLett.113.257401]. It is found that the evolution of the BICs, including their creation and annihilation, under variation of geometric parameters is controlled by the topological charge. Three scenarios of such evolution for different leaky zones are described. Finally, it is shown that the topological properties of the BICs can be extracted from transmission spectra when the system is illuminated by a plane wave of circular polarization.
Lead poisoning in United States-bound refugee children: Thailand-Burma border, 2009.
Mitchell, Tarissa; Jentes, Emily; Ortega, Luis; Scalia Sucosky, Marissa; Jefferies, Taran; Bajcevic, Predrag; Parr, Valentina; Jones, Warren; Brown, Mary Jean; Painter, John
2012-02-01
Elevated blood lead levels lead to permanent neurocognitive sequelae in children. Resettled refugee children in the United States are considered at high risk for elevated blood lead levels, but the prevalence of and risk factors for elevated blood lead levels before resettlement have not been described. Blood samples from children aged 6 months to 14 years from refugee camps in Thailand were tested for lead and hemoglobin. Sixty-seven children with elevated blood lead levels (venous ≥10 µg/dL) or undetectable (capillary lead levels participated in a case-control study. Of 642 children, 33 (5.1%) had elevated blood lead levels. Children aged lead levels risk factors included hemoglobin lead levels among tested US-bound Burmese refugee children was higher than the current US prevalence, and was especially high among children lead levels. A population-specific understanding of preexisting lead exposures can enhance postarrival lead-poisoning prevention efforts, based on Centers for Disease Control and Prevention recommendations for resettled refugee children, and can lead to remediation efforts overseas.
Color-suppression of non-planar diagrams in bosonic bound states
Alvarenga Nogueira, J. H.; Ji, Chueng-Ryong; Ydrefors, E.; Frederico, T.
2018-02-01
We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in 3 + 1 space-time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe-Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for Nc = 3, which supports the use of rainbow-ladder truncations in practical non-perturbative calculations within QCD.
Interaction of rigid C3N- with He: Potential energy surface, bound states, and rotational spectrum
Lara-Moreno, Miguel; Stoecklin, Thierry; Halvick, Philippe
2017-06-01
A two-dimensional rigid rotor model of the potential energy surface is developed for the collision of C3N- with He. Ab initio calculations are performed at the coupled cluster level with single and double excitations and using a perturbative treatment of triple excitations. An augmented correlation consistent polarized valence quadruple zeta basis set complemented with a set of mid-bond functions is chosen for these calculations. The global T-shaped minimum (De = 62.114 cm-1) is found at the intermolecular distance R = 6.42 a0. A secondary minimum (De = 41.384 cm-1) is obtained for the linear configuration C3N--He and for R = 9.83 a0. Calculations of the rovibrational bound states are carried out by using a discrete variable representation method based on Sturmian functions. The first theoretical prediction of the absorption spectra for the He-C3N- complex in the microwave region is also provided.
Johansen, J G; Borge, M J G; Cubero, M; Diriken, J; Elsevier, J; Fraile, L M; Fynbo, H O U; Gaffney, L P; Gernhäuser, R; Jonson, B; Koldste, G T; Konki, J; Kröll, T; Krücken, R; Mücher, D; Nilsson, T; Nowak, K; Pakarinen, J; Pesudo, V; Raabe, R; Riisager, K; Seidlitz, M; Tengblad, O; Törnqvist, H; Voulot, D; Warr, N; Wenander, F; Wimmer, K; De Witte, H
2013-01-01
The bound states of $^{12}$Be have been studied through a $^{11}$Be$(d,p)^{12}$Be transfer reaction experiment in inverse kinematics. A 2.8 MeV/u beam of $^{11}$Be was produced using the REX-ISOLDE facility at CERN. The outgoing protons were detected with the T-REX silicon detector array. The MINIBALL germanium array was used to detect $\\gamma$-rays from the excited states in $^{12}$Be. The $\\gamma$-ray detection enabled a clear identification of the four known bound states in $^{12}$Be, and each of the states has been studied individually. Differential cross sections over a large angular range have been extracted. Spectroscopic factors for each of the states have been determined from DWBA calculations and have been compared to previous experimental and theoretical results.
Localization behavior at bound Bi complex states in GaA s1 -xB ix
Alberi, K.; Christian, T. M.; Fluegel, B.; Crooker, S. A.; Beaton, D. A.; Mascarenhas, A.
2017-07-01
While bismuth-related states are known to localize carriers in GaA s1 -xB ix alloys, the localization behavior of distinct Bi pair, triplet, and cluster states bound above the valence band is less well understood. We probe localization at three different Bi complex states in dilute GaA s1 -xB ix alloys using magnetophotoluminescence and time-resolved photoluminescence spectroscopy. The mass of electrons Coulomb-bound to holes trapped at Bi pair states is found to increase relative to the average electron mass in the alloy. This increase is attributed to enhanced local compressive strain in the immediate vicinity of the pairs. The dependence of energy transfer between these states on composition is also explored.
The role of final-state correlations in recombination of atomic hydrogen
Stoof, H.T.C.; Goey, L.P.H. de; Verhaar, B.J.; Glöckle, W.
1987-01-01
We calculate the rate-constant for recombination in the bulk of a spin-polarized atomic hydrogen gas. We use an exact initial state and include the most essential collision aspects of the final state, except for rearrangement.
Summary of informal workshop on state of ion beam facilities for atomic physics research
Energy Technology Data Exchange (ETDEWEB)
Jones, K.W.; Cocke, C.L.; Datz, S.; Kostroun, V.
1984-11-13
The present state of ion beam facilities for atomic physics research in the United States is assessed by means of a questionnaire and informal workshop. Recommendations for future facilities are given. 3 refs.
Carving complex many-atom entangled states by single-photon detection
Chen, Wenlan; Duan, Yiheng; Braverman, Boris; Zhang, Hao; Vuletic, Vladan
2015-01-01
We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multi-frequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. Complex entangled states such as multicomponent Schroedinger cat states can be generated with high fidelity. This probabilistic but fast heralded state-carving method can be made quasi-deterministic by repeated trial and feedback, yields high success probability per trial, and can be implemented with existing technology.
A New Proof of Existence of a Bound State in the Quantum Coulomb Field
Staruszkiewicz, A.
2004-09-01
Let S(x) be a massless scalar quantum field which lives on the three-dimensional hyperboloid xx= (x0)2-(x1)2-(x2)2-(x3)2=-1. The classical action is assumed to be (hbar=1=c)(8π e2)-1int dx gikpartial i Spartial k S, where e2 is the coupling constant, dx is the invariant measure on the de Sitter hyperboloid xx=-1 and gik, i,k=1,2,3, is the internal metric on this hyperboloid. Let u be a fixed four-velocity i.e. a fixed unit time-like vector. The field S(u)=(1/4 π )int dxδ (ux)S(x)is smooth enough to be exponentiated, being an average of the operator valued distribution S(x) over the entire Cauchy surface ux=0. We prove that if 0 = exp (-iS(u))mid 0>, where mid 0 > is the Lorentz invariant vacuum state, contains a normalizable eigenstate of the Casimir operator C1=-(1/2)Mμ ν Mμ ν ; Mμ ν are generators of the proper orthochronous Lorentz group. The eigenvalue is (e2/π )(2-(e2/π )). This theorem was first proven by the Author in 1992 in his contribution to the Czyz Festschrift, see Erratum Acta Phys. Pol. B 23, 959 (1992). In this paper a completely different proof is given: we derive the partial, differential equation satisfied by the matrix element , σ > 0, and show that the function exp(z)\\cdot (1-z)\\cdot exp [-σ z (2-z)], z= e2/ π , is an exact solution of this differential equation, recovering thus both the eigenvalue and the probability of occurrence of the bound state. A beautiful integral is calculated as a byproduct.
Wang, Xude; Luo, Aiping; Luo, Zhichao; Liu, Meng; Zou, Feng; Zhu, Yanfang; Xue, Jianping; Xu, Wencheng
2017-11-01
We presented a bound-state operation in a fiber laser with near-zero anomalous dispersion based on a silica-coated gold nanorods (GNRs@SiO2) saturable absorber (SA). Using a balanced twin detector measurement technique, the modulation depth and nonsaturable loss of the GNRs@SiO2 SA were measured to be approximately 3.5% and 39.3%, respectively. By virtue of the highly nonlinear effect of the GNRs@SiO2 SA, the bound-state pulses could be easily observed. Besides the lower-order bound-state pulses with two, three, and four solitons, the higher-order bound states with up to 12 solitons were also obtained in the laser cavity. The pulse profiles of the higher-order bound states were further reconstructed theoretically. The experimental results would give further insight towards understanding the complex nonlinear dynamics of bound-state pulses in fiber lasers.
Calculations of antiproton nucleus quasi-bound states using the Paris (N)over-barN potential
Czech Academy of Sciences Publication Activity Database
Hrtánková, Jaroslava; Mareš, Jiří
2018-01-01
Roč. 969, č. 1 (2018), s. 45-59 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : antiproton-nucleus interaction * Paris (N)over-barN potential * antiproton-nuclear bound states Subject RIV: BE - Theoretical Physics Impact factor: 1.916, year: 2016
Energy Technology Data Exchange (ETDEWEB)
Andrade, F.M., E-mail: fmandrade@uepg.br [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa-PR (Brazil); Silva, E.O., E-mail: edilbertoo@gmail.com [Departamento de Física, Universidade Federal do Maranhão, Campus Universitário do Bacanga, 65085-580 São Luís-MA (Brazil); Pereira, M., E-mail: marciano@uepg.br [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa-PR (Brazil)
2013-12-15
In this work the bound state and scattering problems for a spin- 1/2 particle undergone to an Aharonov–Bohm potential in a conical space in the nonrelativistic limit are considered. The presence of a δ-function singularity, which comes from the Zeeman spin interaction with the magnetic flux tube, is addressed by the self-adjoint extension method. One of the advantages of the present approach is the determination of the self-adjoint extension parameter in terms of physics of the problem. Expressions for the energy bound states, phase-shift and S matrix are determined in terms of the self-adjoint extension parameter, which is explicitly determined in terms of the parameters of the problem. The relation between the bound state and zero modes and the failure of helicity conservation in the scattering problem and its relation with the gyromagnetic ratio g are discussed. Also, as an application, we consider the spin- 1/2 Aharonov–Bohm problem in conical space plus a two-dimensional isotropic harmonic oscillator. -- Highlights: •Planar dynamics of a spin- 1/2 neutral particle. •Bound state for Aharonov–Bohm systems. •Aharonov–Bohm scattering. •Helicity nonconservation. •Determination of the self-adjoint extension parameter.
Fujioka, H.; Ayyad, Y.; Benlliure, J.; Brinkmann, K. -T.; Friedrich, S.; Geissel, H.; Gellanki, J.; Guo, C.; Gutz, E.; Haettner, E.; Harakeh, M. N.; Hayano, R. S.; Higashi, Y.; Hirenzaki, S.; Hornung, C.; Igarashi, Y.; Ikeno, N.; Itahashi, K.; Iwasaki, M.; Jido, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knoebel, R.; Kurz, N.; Metag, V.; Mukha, I.; Nagae, T.; Nagahiro, H.; Nanova, M.; Nishi, T.; Ong, H. J.; Pietri, S.; Prochazka, A.; Rappold, C.; Reiter, M. P.; Rodríguez-Sánchez, J. L.; Scheidenberger, C.; Simon, H.; Sitar, B.; Strmen, P.; Sun, B.; Suzuki, K.; Szarka, I.; Takechi, M.; Tanaka, Y. K.; Tanihata, I.; Terashima, S.; Watanabe, Y. N.; Weick, H.; Widmann, E.; Winfield, J. S.; Xu, X.; Yamakami, H.; Zhao, J.
2015-01-01
The possible existence of \\eta'-nucleus bound states has been put forward through theoretical and experimental studies. It is strongly related to the \\eta' mass at finite density, which is expected to be reduced because of the interplay between the $U_A(1)$ anomaly and partial restoration of chiral
Yokoyama, T.; Reutlinger, Johannes; Belzig, Wolfgang; Nazarov, Y.V.
2017-01-01
We consider the spectrum of Andreev bound states (ABSs) in an exemplary four-terminal superconducting structure where four chaotic cavities are connected by quantum point contacts to the terminals and to each other forming a ring. We nickname the resulting device 4T-ring. Such a tunable device
DEFF Research Database (Denmark)
Bogdanov, A. A.; Sadrieva, Z. F.; Sinev, I. S.
2017-01-01
We experimentally and theoretically analyze the role of substrate on the optical bound states in the continuum (BICs). We reveal that a high-index substrate could destroy even in-plane symmetry protected BIC due to leakage into the diffraction channels opening in the substrate. We show how two...
Seo, Kangjun; Sau, Jay D.; Tewari, Sumanta
2017-05-01
We investigate the effect of spin-orbit coupling on the in-gap bound states localized at magnetic impurities in multiband superconductors with unconventional (sign-changed) and conventional (sign-unchanged) s -wave pairing symmetry, which may be relevant to iron-based superconductors. Without spin-orbit coupling, for spin-singlet superconductors it is known that such bound states cross zero energy at a critical value of the impurity scattering strength and acquire a finite spin polarization. Moreover, the degenerate, spin-polarized, zero-energy bound states are unstable to applied Zeeman fields as well as a deviation of the impurity scattering strength away from criticality. Using a T -matrix formalism as well as analytical arguments, we show that, in the presence of spin-orbit coupling, the zero-energy bound states localized at magnetic impurities in unconventional, sign-changed, s -wave superconductors acquire surprising robustness to applied Zeeman fields and variation in the impurity scattering strength, an effect which is absent in the conventional, sign-unchanged, s -wave superconductors. Given that the iron-based multiband superconductors may possess a substantial spin-orbit coupling as seen in recent experiments, our results may provide one possible explanation to the recent observation of surprisingly robust zero bias scanning tunneling microscope peaks localized at magnetic impurities in iron-based superconductors provided the order parameter symmetry is sign changing s+--wave.
Weakly bound states of two- and three-boson systems in the crossover from two to three dimensions
DEFF Research Database (Denmark)
Yamashita, Marcelo; Bellotti, Filipe Furlan; Frederico, Tobias
2015-01-01
The spectrum and properties of quantum bound states is strongly dependent on the dimensionality of space. How this comes about and how one may theoretically and experimentally study the interpolation between different dimensions is a topic of great interest in different fields of physics. In this...
Emelin, M. Yu.; Smirnov, L. A.; Ryabikin, M. Yu.
2017-10-01
The results of both quantum-mechanical numerical calculations beyond the electric dipole approximation and relativistic classical Monte Carlo simulations are presented for a ground-state hydrogen atom exposed to a high-frequency circularly polarized laser field in a wide intensity range. The persistence of the light-induced metastable bound states well into the relativistic regime of laser-atom interaction is demonstrated. The feasibility of high-efficiency electron trapping into these metastable states is examined in the frame of a simple two-stage scenario for a laser field turning on. The optimal parameters of the laser pulse front are found, which provide an optimal balance between the needs to achieve as quickly as possible the higher intensities, for which the decay rate of the metastable states is lower, and to ensure sufficient adiabaticity of the field turning on to avoid the unwanted "shake-off" processes. As a result, more than 60% probability of electron trapping into the metastable states in a relativistically intense high-frequency laser field is demonstrated.
Energy Technology Data Exchange (ETDEWEB)
Miserev, D. S., E-mail: d.miserev@student.unsw.edu.au, E-mail: erazorheader@gmail.com [University of New South Wales, School of Physics (Australia)
2016-06-15
The problem of localized states in 1D systems with a relativistic spectrum, namely, graphene stripes and carbon nanotubes, is studied analytically. The bound state as a superposition of two chiral states is completely described by their relative phase, which is the foundation of the variable phase method (VPM) developed herein. Based on our VPM, we formulate and prove the relativistic Levinson theorem. The problem of bound states can be reduced to the analysis of closed trajectories of some vector field. Remarkably, the Levinson theorem appears as the Poincaré index theorem for these closed trajectories. The VPM equation is also reduced to the nonrelativistic and semiclassical limits. The limit of a small momentum p{sub y} of transverse quantization is applicable to an arbitrary integrable potential. In this case, a single confined mode is predicted.
Cooling a Single Atom in an Optical Tweezer to Its Quantum Ground State
Directory of Open Access Journals (Sweden)
A. M. Kaufman
2012-11-01
Full Text Available We report cooling of a single neutral atom to its three-dimensional vibrational ground state in an optical tweezer. After employing Raman sideband cooling for tens of milliseconds, we measure via sideband spectroscopy a three-dimensional ground-state occupation of about 90%. We further observe coherent control of the spin and motional state of the trapped atom. Our demonstration shows that an optical tweezer, formed simply by a tightly focused beam of light, creates sufficient confinement for efficient sideband cooling. This source of ground-state neutral atoms will be instrumental in numerous quantum simulation and logic applications that require a versatile platform for storing and manipulating ultracold single neutral atoms. For example, these results will improve current optical-tweezer experiments studying atom-photon coupling and Rydberg quantum logic gates, and could provide new opportunities such as rapid production of single dipolar molecules or quantum simulation in tweezer arrays.
Czech Academy of Sciences Publication Activity Database
Pavelková, Lenka
2011-01-01
Roč. 47, č. 3 (2011), s. 370-384 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : non-linear state space model * bounded uncertainty * missing measurements * state filtering * vehicle position estimation Subject RIV: BC - Control Systems Theory Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/AS/pavelkova-0360239.pdf
Preparation of entangled Dicke states using atomic ensembles
Franquet González, Albert
2013-01-01
Treball final de màster oficial fet en col·laboració amb Universitat Autònoma de Barcelona (UAB), Universitat de Barcelona (UB) i Institut de Ciències Fotòniques (ICFO) [ANGLÈS] Phenomena associated with collective interactions in atom-nanofiber interfaces have been of great interest. Here, we show how multipartite entanglement in atomic ensembles can emerge from collective emission in combination with photon detection. We present a novel group theoretical technique to efficiently calculat...
Emergence of quasiparticle Bloch states in artificial crystals crafted atom-by-atom
Directory of Open Access Journals (Sweden)
Jan Girovsky, Jose L. Lado, Floris E. Kalff, Eleonora Fahrenfort, Lucas J. J. M. Peters, Joaquín Fernández-Rossier, Alexander F. Otte
2017-06-01
Full Text Available The interaction of electrons with a periodic potential of atoms in crystalline solids gives rise to band structure. The band structure of existing materials can be measured by photoemission spectroscopy and accurately understood in terms of the tight-binding model, however not many experimental approaches exist that allow to tailor artificial crystal lattices using a bottom-up approach. The ability to engineer and study atomically crafted designer materials by scanning tunnelling microscopy and spectroscopy (STM/STS helps to understand the emergence of material properties. Here, we use atom manipulation of individual vacancies in a chlorine monolayer on Cu(100 to construct one- and two-dimensional structures of various densities and sizes. Local STS measurements reveal the emergence of quasiparticle bands, evidenced by standing Bloch waves, with tuneable dispersion. The experimental data are understood in terms of a tight-binding model combined with an additional broadening term that allows an estimation of the coupling to the underlying substrate.
The ground state properties of spin-aligned atomic hydrogen, deuterium, and tritium
Etters, R. D.; Dugan, J. V., Jr.; Palmer, R. W.
1975-01-01
The internal energy, pressure, and compressibility of ground-state, spin-aligned atomic hydrogen, deuterium, and tritium are calculated assuming that all pair interactions occur via the atomic triplet (spin-aligned) potential. The conditions required to obtain atomic hydrogen and its isotopes in bulk are discussed; such a development would be of value in propulsion systems because of the light mass and energetic recombination of atomic hydrogen. Results show that atomic triplet hydrogen and deuterium remain gaseous at 0 K, and that tritium forms a liquid with a binding energy of approximately -0.75 K per atom at a molar volume of 130 cu cm per mole. The pair distribution function for these systems is calculated, and the predicted superfluid behavior of atomic triplet hydrogen and tritium is briefly discussed.
State-to-state modeling of non equilibrium low-temperature atomic plasmas
Bultel, Arnaud; Morel, Vincent; Annaloro, Julien; Druguet, Marie-Claude
2017-03-01
The most relevant approach leading to a thorough understanding of the behavior of non equilibrium atomic plasmas is to elaborate state-to-state models in which the mass conservation equation is applied directly to atoms or ions on their excited states. The present communication reports the elaboration of such models and the results obtained. Two situations close to each other are considered. First, the plasmas produced behind shock fronts obtained in ground test facilities (shock tubes) or during planetary atmospheric entries of spacecrafts are discussed. We focused our attention on the nitrogen case for which a complete implementation of the CoRaM-N2 collisional-radiative model has been performed in a steady one-dimensional computation code based on the Rankine-Hugoniot assumptions. Second, the plasmas produced by the interaction between an ultra short laser pulse and a tungsten sample are discussed in the framework of the elaboration of the Laser-Induced Breakdown Spectroscopy (LIBS) technique. In the present case, tungsten has been chosen in the purpose of validating an in situ experimental method able to provide the elemental composition of the divertor wall of a tokamak like WEST or ITER undergoing high energetic deuterium and tritium nuclei fluxes.
Lifetime measurement of excited atomic and ionic states of some ...
Indian Academy of Sciences (India)
Abstract. High-frequency deflection (HFD) technique with a delayed coincidence single photon counting arrangement is an efficient technique for radiative lifetime measurement. An apparatus for measurement of the radiative lifetime of atoms and molecules has been developed in our laboratory and measurements have ...
Lifetime measurement of excited atomic and ionic states of some ...
Indian Academy of Sciences (India)
High-frequency deflection (HFD) technique with a delayed coincidence single photon counting arrangement is an efficient technique for radiative lifetime measurement. An apparatus for measurement of the radiative lifetime of atoms and molecules has been developed in our laboratory and measurements have been ...
Dynamics Resonances in Atomic States of Astrophysical Relevance
Indian Academy of Sciences (India)
This research grounded the applicability of quasi-classics in describing the development of dynamic chaos phenomena in a quasi-hydrogen Rydberg alkali atom and showed the difference of the arising pro- cess of 'stochastic diffusion' from multiphoton and tunnel ionizations in a diatomic quasi-molecular complex.
The ρ(ω/B*(B system and bound states in the unitary local Hidden Gauge approach
Directory of Open Access Journals (Sweden)
Fernandez-Soler P.
2016-01-01
Full Text Available In this work, we study systems composed of a ρ/ω and B* meson pair. We find three bound states in isospin, spin-parity channels (1/2, 0+, (1/2, 1+ and (1/2, 2+. The state with J = 2 can be a good candidate for the B*2(5747. We also study the ρB system, and a bound state with mass 5728 MeV and width around 20 MeV is obtained, which can be identified with the B1(5721 resonance. In the case of I = 3/2, one obtains repulsion and thus, no exotic (molecular mesons in this sector are generated in the approach.
In-medium bound-state formation and inhomogeneous condensation in Fermi gases in a hard-wall box
Roscher, Dietrich; Braun, Jens
2017-10-01
The formation of bosonic bound states underlies the formation of a superfluid ground state in the many-body phase diagram of ultracold Fermi gases. We study bound-state formation in a spin- and mass-imbalanced ultracold Fermi gas confined in a box with hard-wall boundary conditions. Because of the presence of finite Fermi spheres, the center-of-mass momentum of the potentially formed bound states can be finite, depending on the parameters controlling mass and spin imbalance as well as the coupling strength. We exploit this observation to estimate the potential location of inhomogeneous phases in the many-body phase diagram as a function of spin- and mass imbalance as well as the box size. Our results suggest that a hard-wall box does not alter substantially the many-body phase diagram calculated in the thermodynamic limit. Therefore, such a box may serve as an ideal trap potential to bring experiment and theory closely together and facilitate the search for exotic inhomogeneous ground states.
Bubble-bound state of triple-stranded DNA: Efimov physics in DNA with repulsion
Maji, Jaya; Seno, Flavio; Trovato, Antonio; Bhattacharjee, Somendra M.
2017-07-01
The presence of a thermodynamic phase of a three-stranded DNA, namely, a mixed phase of bubbles of two bound strands and a single one, is established for large dimensions (d≥slant 5 ) by using exact real space renormalization group transformations and exact computations of specific heat for finite length chains. Similar exact computations for the fractal Sierpinski gasket of dimension d stability of the phase in the presence of a repulsive three chain interaction. Although, for d DNA, where three strands are bound though no two are bound, the mixed phase appears at temperatures less than the two chain melting temperature. Both the Efimov-DNA and the mixed phase are formed essentially due to the strand exchange mechanism.
Application of solid state NMR for the study of surface bound species and fossil fuels
Althaus, Stacey
Recent advances in solid state NMR have been utilized to study a variety of systems. These advancements have allowed for the acquisition of sequences previously only available for solution state detection. The protocol for the measurement of coals and other carbonaceous materials was updated to incorporate the recent advancements in fast magic angle spinning (MAS) and high magnetic fields. Argonne Premium Coals were used to test the sensitivity and resolution of the experiments preformed at high field and fast MAS. The higher field spectra were shown to be slightly less sensitive than the traditional lower field spectra, however, the new high field fast MAS spectra had better resolution. This increased resolution allowed for the separation of a variety of different functional groups, thereby allowing the composition of the coal to be determined. The use of 1 H detection allowed for 2D spectra of coals for the first time. These spectra could be filtered to examine either through-space or through-bond correlations. Indirect detection via 1 H was also pivotal in the detection of natural abundance 15 N spectra. Through-space and through-bond 2D spectra of natural abundance bulk species are shown with a sensitivity increase of 15 fold over traditional detection. This sensitivity enhancement allowed for the detection of natural abundance 15 N surface bound species in 2D, something that could not be acquired via traditional methods. The increased efficiency of the through-space magnetization transfer, Cross polarization, at fast MAS compared to the slower MAS rates is shown. The through-bond magnetization transfer via INEPT was examined and the effect of J-coupling is confirmed. Solid State NMR can be utilized to help improve catalytic interactions. Solid state NMR was used to examine the aldol condensation between p-nitrobenzaldehyde and acetone. The formation of a stable intermediate with p-nitrobenzaldehyde was found on the primary functionalized amine mesoporous
Atom capture by nanotube and scaling anomaly
Giri, Pulak Ranjan
2007-01-01
The existence of bound state of the polarizable neutral atom in the inverse square potential created by the electric field of single walled charged carbon nanotube (SWNT) is shown to be theoretically possible. The consideration of inequivalent boundary conditions due to self-adjoint extensions lead to this nontrivial bound state solution. It is also shown that the scaling anomaly is responsible for the existence of bound state. Binding of the polarizable atoms in the coupling constant interval \\eta^2\\in[0,1) may be responsible for the smearing of the edge of steps in quantized conductance, which has not been considered so far in literature.
Fujioka, H.; Ayyad, Y.; Benlliure, J.; Brinkmann, K.-T.; Friedrich, S.; Geissel, H.; Gellanki, J.; Guo, C.; Gutz, E.; Haettner, E.; Harakeh, M. N.; Hayano, R. S.; Higashi, Y.; Hirenzaki, S.; Hornung, C.; Igarashi, Y.; Ikeno, N.; Itahashi, K.; Iwasaki, M.; Jido, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knoebel, R.; Kurz, N.; Metag, V.; Mukha, I.; Nagae, T.; Nagahiro, H.; Nanova, M.; Nishi, T.; Ong, H. J.; Pietri, S.; Prochazka, A.; Rappold, C.; Reiter, M. P.; Rodríguez-Sánchez, J. L.; Scheidenberger, C.; Simon, H.; Sitar, B.; Strmen, P.; Sun, B.; Suzuki, K.; Szarka, I.; Takechi, M.; Tanaka, Y. K.; Tanihata, I.; Terashima, S.; Watanabe, Y. N.; Weick, H.; Widmann, E.; Winfield, J. S.; Xu, X.; Yamakami, H.; Zhao, J.
2015-08-01
The possible existence of η'-nucleus bound states has been put forward through theoretical and experimental studies. It is strongly related to the η' mass at finite density, which is expected to be reduced because of the interplay between the U A (1) anomaly and partial restoration of chiral symmetry. The investigation of the C( p, d) reaction at GSI and FAIR, as well as an overview of the experimental program at GSI and future plans at FAIR are discussed.
Hatleskog, Anne; Lappi, Henna
2010-01-01
The objective of this paper is to assess unconventional monetary policy at the zero nominal bound: First, we assemble a framework for implementing and evaluating unconventional monetary policy. Second, we use the framework to conduct three detailed case studies on unconventional policy responses in Japan, United States and United Kingdom. Third, we make a cross-country analysis of the development in key macroeconomic variables after the adaption of unconventional monetary policies. We find...
How does a synthetic non-Abelian gauge field influence the bound states of two spin- 1 / 2 fermions?
Vyasanakere, Jayantha; Shenoy, Vijay
2011-03-01
We study the bound states of two spin- 1 / 2 fermions interacting via a contact attraction (characterized by the scattering length) in the singlet channel in 3 D space in presence of a uniform non-Abelian gauge field. The configuration of the gauge field that generates a Rashba type spin-orbit interaction is described by three coupling parameters (λx ,λy ,λz) . For a generic gauge field configuration, the critical scattering length required for the formation of a bound state is negative, i.e., shifts to the ``BCS side'' of the resonance. Interestingly, we find that there are special high-symmetry configurations (e.g., λx =λy =λz) for which there is a two body bound state for any scattering length however small and negative. Our results show that the BCS-BEC crossover is drastically affected by the presence of a non-Abelian gauge field. We discuss possible experimental signatures of our findings both at high and low temperatures. Work supported by DST, India through Ramanujan grant.
State-to-state three-atom time-dependent reactive scattering in hyperspherical coordinates.
Crawford, Jeff; Parker, Gregory A
2013-02-07
We present a time-dependent, hyperspherical wave packet method for calculating three-atom state-to-state S-matrix elements. The wave packet is propagated in time using adiabatically adjusting, principal axes hyperspherical coordinates that treat all arrangement channels equivalently, allowing the simultaneous analysis of the products in all three arrangement channels. We take advantage of the symmetry of the potential energy surface and decompose the initial wave packet into its component irreducible representations, propagating each component separately. Each irreducible representation component of the wave packet is analyzed by projecting it onto the hyperspherical basis at a fixed, asymptotic hyperradius, and irreducible representation dependent S-matrix elements are obtained by matching the hyperspherical projections to symmetry-adapted Jacobi coordinate boundary conditions. We obtain arrangement channel-dependent S-matrix elements as linear combinations of the irreducible representation dependent elements. State-to-state H + H(2) and F + H(2) results for zero total angular momentum are presented.
Liu, Tang-Kun; Tao, Yu; Shan, Chuan-Jia; Liu, Ji-bing
2017-10-01
Using the three criterions of the concurrence, the negative eigenvalue and the geometric quantum discord, we investigate the quantum entanglement and quantum correlation dynamics of two two-level atoms interacting with the coherent state optical field. We discuss the influence of different photon number of the mean square fluctuations on the temporal evolution of the concurrence, the negative eigenvalue and the geometric quantum discord between two atoms when the two atoms are initially in specific three states. The results show that different photon number of the mean square fluctuations can lead to different effects of quantum entanglement and quantum correlation dynamics.
Horing, N. J. M.
1997-03-01
An explicit position-space inversion of the dielectric function of a planar quantum well with a bound state embedded in a bulk medium having a 3D band of extended states is carried out here in closed form.The resulting nonlocal dynamic inverse dielectric function K(z,z^';barq,w) is exact within the framework of the random phase approximation with the assumption that the 3D band of extended states is translationally invariant in the z-direction,and that intersubband transitions between the 3D band and the discrete bound state are negligible.The frequency poles of K(z,z^';barq,w) obtained here represent the coupling of nonlocal bulk plasmons with 2D intrasubband plasmons of the quantum well and the residues of these poles provide the oscillator strength of such coupled collective modes.
Superfluid state of repulsively interacting three-component fermionic atoms in optical lattices
Suga, Sei-Ichiro; Inaba, Kensuke
2013-03-01
We investigate the superfluid state of repulsively interacting three-component (color) fermionic atoms in optical lattices using Feynman diagrammatic approaches and the dynamical mean field theory. When the anisotropy of the three repulsive interactions is strong, atoms of two of the three colors form Cooper pairs and atoms of the third color remain a Fermi liquid. This superfluid emerges close to half filling at which the Mott insulating state characteristic of the three-component repulsive fermions appears. An effective attractive interaction is induced by density fluctuations of the third-color atoms. The superfluid state is stable against the phase separation that occurs in the strongly repulsive region. We determine the phase diagrams in terms of temperature, filling, and the anisotropy of the repulsive interactions. This work was supported by Grant-in-Aid for Scientific Research (C) (No. 23540467) from the Japan Society for the Promotion of Science.
Spectrum of Andreev bound states in Josephson junctions with a ferromagnetic insulator
Kawabata, S.; Tanaka, Y.; Golubov, Alexandre Avraamovitch; Vasenko, A.; Asano, Y.
2012-01-01
Ferromagnetic-insulator (FI) based Josephson junctions are promising candidates for a coherent superconducting quantum bit as well as a classical superconducting logic circuit. Recently the appearance of an intriguing atomic-scale 0–π transition has been theoretically predicted. In order to uncover
Kuzmanovski, Dushko; Black-Schaffer, Annica; Linder, Jacob
Silicene, the Si-atom analog of graphene, is a viable candidate for experimental realization of non-trivial topological phases due to the larger spin-orbit coupling. Also, owing to the buckled structure, it allows for tuning of its various band gaps by an applied electric field. An intriguing prospect is to consider effects due to the interplay between the non-trivial band structure and superconducting correlations in silicene, and to study the external control of such unusual phenomena via an electric field. We demonstrate theoretically that proximity-induced superconductivity in silicene offers the possibility to exert strong quantum ground state control. We show that electrically controlled 0- π transitions occur in Josephson junctions in the presence of an exchange field. We also discover that zigzag-oriented interfaces, featuring intervalley scattering, cause a φ0 state with an applied electric field. Additionally, we demonstrate that Majorana bound states along the silicene edge are tunable via the edge orientation, electric, and in-plane spin exchange fields. Finally, we investigate odd-frequency superconducting pair amplitudes in both bulk silicene, and nanoribbons with two kinds of edges.
Kornilov, Oleg; Bünermann, Oliver; Haxton, Daniel J; Leone, Stephen R; Neumark, Daniel M; Gessner, Oliver
2011-07-14
Ultrafast relaxation of electronically excited pure He droplets is investigated by femtosecond time-resolved photoelectron imaging. Droplets are excited by extreme ultraviolet (EUV) pulses with photon energies below 24 eV. Excited states and relaxation products are probed by ionization with an infrared (IR) pulse with 1.6 eV photon energy. An initially excited droplet state decays on a time scale of 220 fs, leading predominantly to the emission of unaligned 1s3d Rydberg atoms. In a second relaxation channel, electronically aligned 1s4p Rydberg atoms are emitted from the droplet within less than 120 fs. The experimental results are described within a model that approximates electronically excited droplet states by localized, atomic Rydberg states perturbed by the local droplet environment in which the atom is embedded. The model suggests that, below 24 eV, EUV excitation preferentially leads to states that are localized in the surface region of the droplet. Electronically aligned 1s4p Rydberg atoms are expected to originate from excitations in the outermost surface regions, while nonaligned 1s3d Rydberg atoms emerge from a deeper surface region with higher local densities. The model is used to simulate the He droplet EUV absorption spectrum in good agreement with previously reported fluorescence excitation measurements.
Probing the Quantum States of a Single Atom Transistor at Microwave Frequencies.
Tettamanzi, Giuseppe Carlo; Hile, Samuel James; House, Matthew Gregory; Fuechsle, Martin; Rogge, Sven; Simmons, Michelle Y
2017-03-28
The ability to apply gigahertz frequencies to control the quantum state of a single P atom is an essential requirement for the fast gate pulsing needed for qubit control in donor-based silicon quantum computation. Here, we demonstrate this with nanosecond accuracy in an all epitaxial single atom transistor by applying excitation signals at frequencies up to ≈13 GHz to heavily phosphorus-doped silicon leads. These measurements allow the differentiation between the excited states of the single atom and the density of states in the one-dimensional leads. Our pulse spectroscopy experiments confirm the presence of an excited state at an energy ≈9 meV, consistent with the first excited state of a single P donor in silicon. The relaxation rate of this first excited state to the ground state is estimated to be larger than 2.5 GHz, consistent with theoretical predictions. These results represent a systematic investigation of how an atomically precise single atom transistor device behaves under radio frequency excitations.
Probabilistic Cloning of two Single-Atom States via Thermal Cavity
Rui, Pin-Shu; Liu, Dao-Jun
2016-12-01
We propose a cavity QED scheme for implementing the 1 → 2 probabilistic quantum cloning (PQC) of two single-atom states. In our scheme, after the to-be-cloned atom and the assistant atom passing through the first cavity, a measurement is carried out on the assistant atom. Based on the measurement outcome we can judge whether the PQC should be continued. If the cloning fails, the other operations are omitted. This makes our scheme economical. If the PQC is continued (with the optimal probability) according to the measurement outcome, two more cavities and some unitary operations are used for achieving the PQC in a deterministic way. Our scheme is insensitive to the decays of the cavities and the atoms.
Generation of multipartite entangled states for chains of atoms in the framework of cavity-QED
Energy Technology Data Exchange (ETDEWEB)
Gonta, Denis
2010-07-07
Cavity quantum electrodynamics is a research field that studies electromagnetic fields in confined spaces and the radiative properties of atoms in such fields. Experimentally, the simplest example of such system is a single atom interacting with modes of a high-finesse resonator. Theoretically, such system bears an excellent framework for quantum information processing in which atoms and light are interpreted as bits of quantum information and their mutual interaction provides a controllable entanglement mechanism. In this thesis, we present several practical schemes for generation of multipartite entangled states for chains of atoms which pass through one or more high-finesse resonators. In the first step, we propose two schemes for generation of one- and two-dimensional cluster states of arbitrary size. These schemes are based on the resonant interaction of a chain of Rydberg atoms with one or more microwave cavities. In the second step, we propose a scheme for generation of multipartite W states. This scheme is based on the off-resonant interaction of a chain of three-level atoms with an optical cavity and a laser beam. We describe in details all the individual steps which are required to realize the proposed schemes and, moreover, we discuss several techniques to reveal the non-classical correlations associated with generated small-sized entangled states. (orig.)
Ilo-Okeke, Ebubechukwu O
2016-01-01
We further examine a theory of phase contrast imaging (PCI) of cold atomic gases, first introduced by us in Phys. Rev. Lett. {\\bf 112}, 233602 (2014). We model the PCI measurement by directly calculating the entangled state between the light and the atoms due to the ac Stark shift, which induces a conditional phase shift on the light depending upon the atomic state. By interfering the light that passes through the BEC with the original light, one can obtain information of the atomic state at a single shot level. We derive an exact expression for a measurement operator that embodies the information obtained from PCI, as well as the back-action on the atomic state. By the use of exact expressions for the measurement process, we go beyond the continuous variables approximation such that the non-Gaussian regime can be accessed for both the measured state and the post-measurement state. Features such as the photon probability density, signal, signal variance, Fisher information, error of the measurement, and the b...
Men'shov, V N; Tugushev, V V; Menshchikova, T V; Eremeev, S V; Echenique, P M; Chulkov, E V
2014-12-03
We apply both analytical and ab-initio methods to explore heterostructures composed of a 3D topological insulator (3D TI) and an ultrathin normal insulator (NI) overlayer as a proving ground for the principles of topological phase engineering. Using the continual model of a semi-infinite 3D TI we study the surface potential (SP) effect caused by an attached ultrathin layer of 3D NI on the formation of topological bound states at the interface. The results reveal that the spatial profile and spectrum of these near-surface states strongly depend on both the sign and the strength of the SP. Using ab-initio band structure calculations to take the specificity of the materials into account, we investigate the NI/TI heterostructures formed by a single tetradymite-type quintuple or septuple layer block and the 3D TI substrate. The analytical continuum theory results relate the near-surface state evolution with the SP variation and are in good qualitative agreement with those obtained from density-functional theory (DFT) calculations. We also predict the appearance of the quasi-topological bound state on the 3D NI surface caused by a local band gap inversion induced by an overlayer.
Rosi, G.; D'Amico, G.; Cacciapuoti, L.; Sorrentino, F.; Prevedelli, M.; Zych, M.; Brukner, Č.; Tino, G. M.
2017-06-01
The Einstein equivalence principle (EEP) has a central role in the understanding of gravity and space-time. In its weak form, or weak equivalence principle (WEP), it directly implies equivalence between inertial and gravitational mass. Verifying this principle in a regime where the relevant properties of the test body must be described by quantum theory has profound implications. Here we report on a novel WEP test for atoms: a Bragg atom interferometer in a gravity gradiometer configuration compares the free fall of rubidium atoms prepared in two hyperfine states and in their coherent superposition. The use of the superposition state allows testing genuine quantum aspects of EEP with no classical analogue, which have remained completely unexplored so far. In addition, we measure the Eötvös ratio of atoms in two hyperfine levels with relative uncertainty in the low 10-9, improving previous results by almost two orders of magnitude.
Rosi, G; D'Amico, G; Cacciapuoti, L; Sorrentino, F; Prevedelli, M; Zych, M; Brukner, Č; Tino, G M
2017-06-01
The Einstein equivalence principle (EEP) has a central role in the understanding of gravity and space-time. In its weak form, or weak equivalence principle (WEP), it directly implies equivalence between inertial and gravitational mass. Verifying this principle in a regime where the relevant properties of the test body must be described by quantum theory has profound implications. Here we report on a novel WEP test for atoms: a Bragg atom interferometer in a gravity gradiometer configuration compares the free fall of rubidium atoms prepared in two hyperfine states and in their coherent superposition. The use of the superposition state allows testing genuine quantum aspects of EEP with no classical analogue, which have remained completely unexplored so far. In addition, we measure the Eötvös ratio of atoms in two hyperfine levels with relative uncertainty in the low 10-9, improving previous results by almost two orders of magnitude.
Probing electronic state at atomic scale on the surface of SrVO3 film
Okada, Yoshinori; Shimizu, Ryota; Shiraki, Susumu; Hitosugi, Taro
2014-03-01
Probing electronic structure of atomically well controlled surface of Perovskite-type 3d transition-metal oxides have been attracting much interest because of their intriguing emergent physical properties by heterostructure engineering. In this study, we have especially focused on SrVO3, where importance of correlation effects has been considered. We successfully obtained atomically flat surfaces of SrVO3, which gave us the great opportunity to visualize correlated electronic state at atomic scale by means of spectroscopic imaging scanning tunneling spectroscopy. Based on the experimental data, we discuss spectroscopic signature of many body effects on the surface of SrVO3 system.
Energy Technology Data Exchange (ETDEWEB)
Lilienthal, David E.; Bacher, Robert F.; Pike, Sumner T.; Strauss, Lewis L.; Waymack, William W.
1948-02-02
The document includes the letter of submittal and the third semiannual report. These reports are called for pursuant to Section 17 of the Atomic Energy Act of 1946. The letter of submittal was titled ''Letter from the Chairman and Members of the United States Atomic Energy Commission transmitting pursuant to law the third semiannual report of the Atomic Energy Commission''. It was authored by David E. Lilienthal, Chairman, and Robert F. Bacher, Sumner T. Pike, Lewis L. Strauss, and William W. Waymack of the AEC.
State-insensitive trapping of Rb atoms: Linearly versus circularly polarized light
Arora, Bindiya; Sahoo, B. K.
2012-09-01
We study the cancellation of differential ac Stark shifts in the 5s and 5p states of the rubidium atom using the linearly and circularly polarized lights by calculating their dynamic polarizabilities. Matrix elements were calculated using a relativistic coupled-cluster method at the single and double excitations and at the important valence triple excitation approximation including all possible nonlinear correlation terms. Some of the important matrix elements were further optimized using the experimental results available for the lifetimes and static polarizabilities of atomic states. “Magic wavelengths” are determined from the differential Stark shifts and results for the linearly polarized light are compared with the previously available results. The possible scope of facilitating state-insensitive optical trapping schemes using the magic wavelengths for circularly polarized light is discussed. Using the optimized matrix elements, the lifetimes of the 4d and 6s states of this atom are ameliorated.
Topcu, T
2016-01-01
We predict the possibility of "triply-magic" optical lattice trapping of neutral divalent atoms. In such a lattice, the ${^1}\\!S_{0}$ and ${^3}\\!P_{0}$ clock states and an additional Rydberg state experience identical optical potentials, fully mitigating detrimental effects of the motional decoherence. In particular, we show that this triply magic trapping condition can be satisfied for Yb atom at optical wavelengths and for various other divalent systems (Ca, Mg, Hg and Sr) in the UV region. We assess the quality of triple magic trapping conditions by estimating the probability of excitation out of the motional ground state as a result of the excitations between the clock and the Rydberg states. We also calculate trapping laser-induced photoionization rates of divalent Rydberg atoms at magic frequencies. We find that such rates are below the radiative spontaneous-emission rates, due to the presence of Cooper minima in photoionization cross-sections.
Numerical calculation of the ground state of Helium atom using ...
African Journals Online (AJOL)
Hylleraas did the calculation of the ground state in 1926 using the variational parameter a. In this paper we trace Hylleraas historic calculation, the use of computer enables us to improve the approximation found by Hylleraas . The program was written in FORTRAN language, designed in such away that for a particular value ...
Preparation of spin squeezed atomic states by optical phase shift measurement
Bouchoule, Isabelle; Moelmer, Klaus
2002-01-01
In this paper we present a state vector analysis of the generation of atomic spin squeezing by measurement of an optical phase shift. The frequency resolution is improved when a spin squeezed sample is used for spectroscopy in place of an uncorrelated sample. When light is transmitted through an atomic sample some photons will be scattered out of the incident beam, and this has a destructive effect on the squeezing. We present quantitative studies for three limiting cases: the case of a sampl...
Friedrich, Harald
2017-01-01
This expanded and updated well-established textbook contains an advanced presentation of quantum mechanics adapted to the requirements of modern atomic physics. It includes topics of current interest such as semiclassical theory, chaos, atom optics and Bose-Einstein condensation in atomic gases. In order to facilitate the consolidation of the material covered, various problems are included, together with complete solutions. The emphasis on theory enables the reader to appreciate the fundamental assumptions underlying standard theoretical constructs and to embark on independent research projects. The fourth edition of Theoretical Atomic Physics contains an updated treatment of the sections involving scattering theory and near-threshold phenomena manifest in the behaviour of cold atoms (and molecules). Special attention is given to the quantization of weakly bound states just below the continuum threshold and to low-energy scattering and quantum reflection just above. Particular emphasis is laid on the fundamen...
Zayarnyi, D. A.; L'dov, A. Yu; Kholin, I. V.
2014-11-01
The processes of collision quenching of the resonance 5s[3/2]1o(3P1) state of the krypton atom are studied by the absorption probe method in electron-beam-excited high-pressure He - Kr mixtures with a low content of krypton. The rate constants of plasmochemical reactions Kr* + Kr + He → Kr*2 + He [(4.21 ± 0.42) × 10-33 cm6 s-1], Kr* + 2He → HeKr* + He [(4.5 ± 1.2) × 10-36 cm6 s-1] and Kr* + He → products + He [(2.21 ± 0.22) × 10-15 cm3 s-1] are measured for the first time. The rate constants of similar reactions are refined for krypton in the metastable 5s[3/2]2o (3P2) state.
Nonlinear Sensing With Collective States of Ultracold Atoms in Optical Lattices
2015-04-02
Letters (submitted) (09 2012) TOTAL: 6 Received Book TOTAL: Patents Submitted Patents Awarded Awards Graduate Students Names of Post Doctorates Names of...states. The atomic state is also indicated by small oriented arrows. The gray and red boxes correspond to unitary operations. Detectors (brown) measure
Probing an Excited-State Atomic Transition Using Hyperfine Quantum Beat Spectroscopy
Wade, Christopher G; Keaveney, James; Adams, Charles S; Weatherill, Kevin J
2014-01-01
We describe a method to observe the dynamics of an excited-state transition in a room temperature atomic vapor using hyperfine quantum beats. Our experiment using cesium atoms consists of a pulsed excitation of the D2 transition, and continuous-wave driving of an excited-state transition from the 6P$_{3/2}$ state to the 7S$_{1/2}$ state. We observe quantum beats in the fluorescence from the 6P$_{3/2}$ state which are modified by the driving of the excited-state transition. The Fourier spectrum of the beat signal yields evidence of Autler-Townes splitting of the 6P$_{3/2}$, F = 5 hyperfine level and Rabi oscillations on the excited-state transition. A detailed model provides qualitative agreement with the data, giving insight to the physical processes involved.
Gao, Yide; Alecu, I M; Hsieh, P-C; Morgan, Brad P; Marshall, Paul; Krasnoperov, Lev N
2006-06-01
The rate constant for Cl + NH3 --> HCl + NH2 has been measured over 290-570 K by the time-resolved resonance fluorescence technique. Ground-state Cl atoms were generated by 193 nm excimer laser photolysis of CCl4 and reacted under pseudo-first-order conditions with excess NH3. The forward rate constant was fit by the expression k1 = (1.08 +/- 0.05) x 10(-11) exp(-11.47 +/- 0.16 kJ mol(-1)/RT) cm3 molecule(-1) s(-1), where the uncertainties in the Arrhenius parameters are +/-1 sigma and the 95% confidence limits for k1 are +/-11%. To rationalize the activation energy, which is 7.4 kJ mol(-1) below the endothermicity in the middle of the 1/T range, the potential energy surface was characterized with MPWB1K/6-31++G(2df,2p) theory. The products NH2 + HCl form a hydrogen-bonded adduct, separated from Cl + NH3 by a transition state lower in energy than the products. The rate constant for the reverse process k(-1) was derived via modified transition state theory, and the computed k(-1) exhibits a negative activation energy, which in combination with the experimental equilibrium constant yields k1 in fair accord with experiment.
Kidun, O; Berakdar, J
2002-01-01
Following the framework of the variable-phase approach, we derive an equation for determining the scattering amplitude of a non-relativistic quantum particle in a non-local potential. Its solution implies the integration of the Volterra integro-differential equation of the first kind and allows determination of bound-state energies and wavefunctions. A fast numerical scheme for the solution of these equations is suggested and it is demonstrated that the proposed method requires the numerical efforts of the same order as in the local potential case.
Golub, A; Kuzmenko, I; Avishai, Y
2011-10-21
Electron transport through a normal-metal-quantum-dot-topological-superconductor junction is studied and reveals interlacing physics of Kondo correlations with two Majorana fermions bound states residing on the opposite ends of the topological superconductor. When the strength of the Majorana fermion coupling exceeds the temperature T, this combination of Kondo-Majorana fermion physics might be amenable for an experimental test: The usual peak of the temperature dependent zero bias conductance σ(V=0,T) splits and the conductance has a dip at T=0. The heights of the conductance side peaks decrease with magnetic field. © 2011 American Physical Society
Sedlmayr, Nicholas; Kaladzhyan, Vardan; Dutreix, Clément; Bena, Cristina
2017-11-01
The bulk-boundary correspondence establishes a connection between the bulk topological index of an insulator or superconductor, and the number of topologically protected edge bands or states. For topological superconductors in two dimensions, the first Chern number is related to the number of protected bands within the bulk energy gap, and is therefore assumed to give the number of Majorana band states in the system. Here we show that this is not necessarily the case. As an example, we consider a hexagonal-lattice topological superconductor based on a model of graphene with Rashba spin-orbit coupling, proximity-induced s -wave superconductivity, and a Zeeman magnetic field. We explore the full Chern number phase diagram of this model, extending what is already known about its parity. We then demonstrate that, despite the high Chern numbers that can be seen in some phases, these do not strictly always contain Majorana bound states.
Epée Epée, M. D.; Motapon, O.; Darby-Lewis, D.; Tennyson, J.
2017-06-01
The UK molecular R-matrix codes are used to study electron collisions with the {{He}}2+ molecular ion. Full configuration interaction calculations are performed to obtain the potential energy curves of the ground X {}2{{{Σ }}}u+ and the first excited A {}2{{{Σ }}}g+ electronic states of {{He}}2+. Resonances, effective quantum numbers, and resonance widths as a function of the internuclear separation are determined for the lowest singlet {}1{{{Σ }}}g+,{}1{{{Σ }}}u+,{}1{{{\\Pi }}}g and {}1{{{\\Pi }}}u and triplet {}3{{{Σ }}}g+,{}3{{{Σ }}}u+,{}3{{{\\Pi }}}g,{}3{{{\\Pi }}}u and {}3{{{Δ }}}u states, which are relevant for the study of the reactive collision of {{He}}2+ with low-energy electrons. In addition, bound states are also calculated for each symmetry of {{He}}2 at several geometries.
State-to-state chemiluminescence in reactions of Mn atoms with S2Cl2.
Khanniche, Sarah; Levy, Martin Richard
2011-10-21
A combined experimental and time-dependent density functional theory (TDDFT) investigation of the title reaction is presented. Both 'hot' and 'cold' laser-ablated Mn atom beams have been employed to determine the translational excitation functions for production of MnCl*(c(5)Σ(+), d(5)Π, e(5)Δ, e(5)Σ(+), A(7)Π). Analysis in terms of the multiple line-of-centres approach shows that the 'hot' results are dominated by reactions of the second metastable state of Mn, z(8)P(J), all with very low thresholds; while the first metastable state, a(6)D(J), and the ground state, a(6)S, are the precursors in the 'cold' results, all with significant excess barriers. The post-threshold behaviour of most z(8)P(J) and a(6)D(J) reaction channels implies that the transition states shift forward with increasing collision energy. The TDDFT calculations suggest that, while Mn*(z(8)P(J), a(6)D(J)) insertion into the S-Cl bond is facile, the observed chemiluminescence channels mostly derive from abstraction in a preferred linear Mn-Cl-S configuration, and that the low z(8)P(J) thresholds originate from attractive but excited reagent potentials which either reach a seam of interactions in the product valley or (in the c(5)Σ(+) case) lead to an octet potential very close in energy to the product sextet. The excess barriers in the Mn*(a(6)D(J)) and Mn(a(6)S) reactions appear for the most part to derive from exit channel mixing with lower-lying product potentials. The observed transition state shifts are consistent with the system being forced to ride up the repulsive wall of the entrance valley as collision energy increases, the location of that wall being different for the z(8)P(J) and a(6)D(J) cases. This journal is © the Owner Societies 2011
The reactions of ground and excited state sodium atoms with hydrogen halide molecules
Weiss, P. S.; Mestdagh, J. M.; Covinsky, M. H.; Balko, B. A.; Lee, Y. T.
1988-10-01
The reactions of ground and excited state Na atoms with hydrogen halide (HX) molecules have been studied using the crossed molecular beams method. With both increasing translational and increasing electronic energy, the reactive cross sections increase in the reactions of HCl and HBr. From product angular and velocity distributions detailed center-of-mass information is derived. For the reactions of Na (3 2S 1/2, 3 2P 1/2, 4 2D 5/2, 5 2S 1/2) with HCl, the product NaCl is back-scattered with respect to the incoming Na atom in the center-of-mass frame of reference. The reaction of each Na state studied with HCl is direct and proceeds via collinear and near-collinear Na-Cl-H approach geometries. For the Na (3 2P 3/2) and Na (4 2D 5/2) reactions with HCl the predominant transition state symmetry is 2Σ in a collinear (C ∞ν) Na-Cl-H geometry. This is consistent with the reaction proceeding via electron transfer from the Na atom to the halide atom. Absolute reactive cross sections for each state of Na studied with HCl were determined by comparison with both small and large angle elastic scattering. We were unable to observe Na atoms with over 4 eV of electronic energy react with HF up to collision energies of 13 kcal/mole.
Laser spectroscopy of the antiprotonic helium atom – its energy levels and state lifetimes
Hidetoshi, Yamaguchi
2003-01-01
The antiprotonic atom is a three-body exotic system consisting of an antiproton, an electron and a helium nucleus. Its surprising longevity was found and has been studied for more than 10 years. In this work, transition energies and lifetimes of this exotic atom were systematically studied by using the antiproton beam of AD(Antiproton Decelerator) facility at CERN, with an RFQ antiproton decelerator, a narrow-bandwidth laser, Cerenkov counters with fast-response photomultiplier tubes, and cryogenic helium target systems. Thirteen transition energies were determined with precisions of better than 200 ppb by a laser spectroscopy method, together with the elimination of the shift effect caused by collisions with surrounding atoms. Fifteen lifetimes (decay rates) of short-lived states were determined from the time distributions of the antiproton-annihilation signals and the resonance widths of the atomic spectral lines. The relation between the magnitude of the decay rates and the transition multipolarity was inv...
Benchmark calculations of low-lying triplet states of Be atom
Bubin, Sergiy
Benchmark variational calculations of several lowest triplet states of the beryllium atom are reported. The wave functions of the states were expanded in terms of highly optimized explicitly correlated Gaussian basis sets and accurate energies are deterimed assuming finite nuclear mass of the atom. These wave functions were used to compute various expectation values, including those that appear in the leading relativistic and QED corrections. Density distributions and pair correlation functions are analyzed for both electrons an nucleus. This work has been supported by the Ministry of Education and Science of Kazakhstan.
Ground state of the hydrogen atom via Dirac equation in a minimal-length scenario
Energy Technology Data Exchange (ETDEWEB)
Antonacci Oakes, T.L.; Francisco, R.O.; Fabris, J.C.; Nogueira, J.A. [Universidade Federal do Espirito Santo, Departamento de Fisica, Vitoria (Brazil)
2013-07-15
In this work we calculate the correction to the ground state energy of the hydrogen atom due to contributions arising from the presence of a minimal length. The minimal-length scenario is introduced by means of modifying the Dirac equation through a deformed Heisenberg algebra (Kempf algebra). With the introduction of the Coulomb potential in the new Dirac energy operator, we calculate the energy shift of the ground state of the hydrogen atom in first order of the parameter related to the minimal length via perturbation theory. (orig.)
Ground state atomic oxygen in high-power impulse magnetron sputtering: a quantitative study
Britun, Nikolay; Belosludtsev, Alexandr; Silva, Tiago; Snyders, Rony
2017-02-01
The ground state density of oxygen atoms in reactive high-power impulse magnetron sputtering discharges has been studied quantitatively. Both time-resolved and space-resolved measurements were conducted. The measurements were performed using two-photon absorption laser-induced fluorescence (TALIF), and calibrated by optical emission actinometry with multiple Ar emission lines. The results clarify the dynamics of the O ground state atoms in the discharge afterglow significantly, including their propagation and fast decay after the plasma pulse, as well as the influence of gas pressure, O2 admixture, etc.
Influence of quasi-bound states on the carrier capture into quantum dots
DEFF Research Database (Denmark)
Magnúsdóttir, Ingibjörg; Uskov, A.; Bischoff, Svend
2002-01-01
An important characteristic of quantum dot (QD) materials is the timescale on which carriers are captured into the dots and relax to their ground state. The properties of devices based on QDs, such as lasers, thus rely on efficient carrier feeding to the active QD states. These processes are beli...
Topologically protected bound states in photonic parity-time-symmetric crystals
Weimann, S.; Kremer, M.; Plotnik, Y.; Lumer, Y.; Nolte, S.; Makris, K. G.; Segev, M.; Rechtsman, M. C.; Szameit, A.
2017-04-01
Parity-time (PT)-symmetric crystals are a class of non-Hermitian systems that allow, for example, the existence of modes with real propagation constants, for self-orthogonality of propagating modes, and for uni-directional invisibility at defects. Photonic PT-symmetric systems that also support topological states could be useful for shaping and routing light waves. However, it is currently debated whether topological interface states can exist at all in PT-symmetric systems. Here, we show theoretically and demonstrate experimentally the existence of such states: states that are localized at the interface between two topologically distinct PT-symmetric photonic lattices. We find analytical closed form solutions of topological PT-symmetric interface states, and observe them through fluorescence microscopy in a passive PT-symmetric dimerized photonic lattice. Our results are relevant towards approaches to localize light on the interface between non-Hermitian crystals.
Search for the He-η bound states with the WASA-at-COSY facility
Directory of Open Access Journals (Sweden)
Krzemien W.
2012-12-01
Full Text Available The η-mesic nuclei in which the η meson is bound with nucleus via strong interaction was postulated already in 1986, however till now no experiment confirmed empirically its existence. The discovery of this new kind of an exotic nuclear matter would be very important for better understanding of the η meson structure and its interaction with nucleons. The search for η-mesic helium is carried out with high statistic and high acceptance with the WASA-at-COSY detection setup in the Research Center Jülich. The search is conducted via the measurement of the excitation function for the chosen decay channels of the 4He-η system. Till now two reactions dd → (4He-ηbs → 3Hepπ− and dd → (4He-ηbs → 3Henπ0 were measured with the beam momentum ramped around the η production threshold. This report includes the description of experimental method and status of the analysis.
Energy Technology Data Exchange (ETDEWEB)
Seaborg, Glenn T.
1962-01-31
This volume contains a name and subject index for the 1961 report of the United States Atomic Energy Commission to Congress. The full semiannual report covers the major unclassified activities of the Commission from January through December 1961.
Energy Technology Data Exchange (ETDEWEB)
Seaborg, Glenn T.
1963-01-31
This volume contains a name and subject index for the 1962 report of the United States Atomic Energy Commission to Congress. The full semiannual report covers the major unclassified activities of the Commission from January through December 1962.
Energy Technology Data Exchange (ETDEWEB)
McCone, John A.
1961-01-31
This volume contains a name and subject index for the 1960 report of the United States Atomic Energy Commission to Congress. The full semiannual report covers the major unclassified activities of the Commission from January through December 1960.
Energy Technology Data Exchange (ETDEWEB)
McCone, John A.
1960-01-31
This volume contains a name and subject index for the 1959 report of the United States Atomic Energy Commission to Congress. The full semiannual report covers the major unclassified activities of the Commission from January through December 1959.
Zayarnyi, D. A.; L'dov, A. Yu; Kholin, I. V.
2013-08-01
We have used the absorption probe method to study the processes of collisional quenching of the metastable 5s [3/2]o2(3P2) state of the krypton atom in electron-beam-excited high-pressure He - Kr mixtures with a low content of krypton. The rate constants of plasma-chemical reactions Kr* + Kr + He → Kr*2+He [(2.88 +/- 0.29) × 10-33 cm6 s-1], Kr* + 2He → HeKr* + He [(4.6 +/- 1.3) × 10-36 cm6 s-1] and Kr* + He → products + He [(1.51 +/- 0.15) × 10-15 cm3 s-1] are measured for the first time. The rate constants of similar reactions in the Ar - Kr mixture are refined.
Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices.
Robens, Carsten; Zopes, Jonathan; Alt, Wolfgang; Brakhane, Stefan; Meschede, Dieter; Alberti, Andrea
2017-02-10
We create low-entropy states of neutral atoms by utilizing a conceptually new optical-lattice technique that relies on a high-precision, high-bandwidth synthesis of light polarization. Polarization-synthesized optical lattices provide two fully controllable optical lattice potentials, each of them confining only atoms in either one of the two long-lived hyperfine states. By employing one lattice as the storage register and the other one as the shift register, we provide a proof of concept using four atoms that selected regions of the periodic potential can be filled with one particle per site. We expect that our results can be scaled up to thousands of atoms by employing an atom-sorting algorithm with logarithmic complexity, which is enabled by polarization-synthesized optical lattices. Vibrational entropy is subsequently removed by sideband cooling methods. Our results pave the way for a bottom-up approach to creating ultralow-entropy states of a many-body system.
Scattering and bound states for the Hulthén potential in a cosmic string background
Hosseinpour, Mansoureh; Andrade, Fabiano M.; Silva, Edilberto O.; Hassanabadi, Hassan
2017-05-01
In this work we study the Dirac equation with vector and scalar potentials in the spacetime generated by a cosmic string. Using an approximation for the centrifugal term, a solution for the radial differential equation is obtained. We consider the scattering states under the Hulthén potential and obtain the phase shifts. From the poles of the scattering S-matrix the states energies are determined as well.
Scattering and bound states for the Hulthen potential in a cosmic string background
Energy Technology Data Exchange (ETDEWEB)
Hosseinpour, Mansoureh; Hassanabadi, Hassan [Shahrood University of Technology, Physics Department, P. O. Box: 3619995161-316, Shahrood (Iran, Islamic Republic of); Andrade, Fabiano M. [Universidade Estadual de Ponta Grossa, Departamento de Matematica e Estatistica, Ponta Grossa, PR (Brazil); Silva, Edilberto O. [Universidade Federal do Maranhao, Departamento de Fisica, Sao Luis, MA (Brazil)
2017-05-15
In this work we study the Dirac equation with vector and scalar potentials in the spacetime generated by a cosmic string. Using an approximation for the centrifugal term, a solution for the radial differential equation is obtained. We consider the scattering states under the Hulthen potential and obtain the phase shifts. From the poles of the scattering S-matrix the states energies are determined as well. (orig.)
Distortion-free propagation in a chiral medium using the coherent superposition of atomic states
Ullah, Sana; Muhammad, Fayaz; Ullah, Irfan; Bacha, Bakht Amin; Arif Ullah, Sayed
2017-11-01
We propose a scheme for distortion free left/right circularly polarized beams in a chiral atomic medium in a tripod-type configuration using the superposition of atomic states. We measure and control the group index, group velocity and delay and advance times for left/right circularly polarized beams in a transparent chiral atomic medium by varying the population distribution probability in the superposition states. For the left and right circularly polarized beams of the probe field, delay and advance times have been observed at resonance and away from resonance. A negligible distortion and large phase shift in the left/right circularly polarized beams is theoretically investigated in the system. The results show potential applications in telecommunication, cloaking base technology and information processing.
Harbola, Varun
2011-01-01
In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron…
Liu, Yecai; Posey, Drew L.; Cetron, Martin S.; Painter, John A.
2015-01-01
Background Before 2007, U.S.-bound immigrants and refugees were screened for tuberculosis (TB) by a smear-based algorithm that could not diagnose smear-negative and culture-positive TB. In 2007, the Centers for Disease Control and Prevention began to implement a culture-based algorithm. Objective To evaluate the effect of the culture-based algorithm on preventing the importation of TB to the United States by immigrants and refugees from foreign countries. Design Population-based, cross-sectional study. Setting Panel physician sites for overseas medical examination. Patients Immigrants and refugees with TB. Measurements Comparison of the increase of smear-negative and culture-positive TB cases diagnosed overseas among immigrants and refugees by the culture-based algorithm with the decline of reported TB cases among foreign-born persons within 1 year after arrival in the United States from 2007 to 2012. Results Of the 3 212 421 arrivals of immigrants and refugees from 2007 to 2012, 1 650 961 (51.4%) were screened by the smear-based algorithm and 1 561 460 (48.6%) were screened by the culture-based algorithm. Among the 4032 TB cases diagnosed by the culture-based algorithm, 2195 (54.4%) were smear-negative and culture-positive. Before implementation (2002 to 2006), the annual number of reported TB cases among foreign-born persons within 1 year after arrival was relatively constant (range, 1424 to 1626 cases; mean, 1504 cases) but decreased from 1511 to 940 cases during implementation (2007 to 2012). During the same period, the annual number of smear-negative and culture-positive TB cases diagnosed overseas among U.S.-bound immigrants and refugees by the culture-based algorithm increased from 4 in 2007 to 629 in 2012. Limitation This analysis did not control for the decline in new arrivals of nonimmigrant visitors to the United States and the decrease of incidence of TB in their countries of origin. Conclusion Implementation of the culture-based algorithm in U.S.-bound
Energy Technology Data Exchange (ETDEWEB)
Wang, Dong-Yang [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wen, Jing-Ji [College of Foundation Science, Harbin University of Commerce, Harbin, Heilongjiang 150028 (China); Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wang, Hong-Fu, E-mail: hfwang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhu, Ai-Dong [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhang, Shou, E-mail: szhang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China)
2015-09-15
An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.
DEFF Research Database (Denmark)
Langbein, W.; Hvam, Jørn Märcher
2002-01-01
We investigate the influence of excitonic localization on the corresponding biexcitonic states in GaAs quantum wells by spectrally resolved four-wave mixing. With increasing localization, the biexciton binding energy increases, while the biexciton continuum shifts to higher energies....... The localization leads to an inhomogeneous broadening of the biexciton binding energy and the biexciton continuum edge. Simultaneously, the oscillator strength of the biexciton continuum-edge is reduced. This is interpreted as a result of the different localization of biexcitonic and excitonic states by the random...
State-dependent self-representations: a culture-bound aspect of identity.
Ghorpade, Amar
2009-03-01
The concepts of identity, self and self-representation have been discussed extensively in psychoanalytic metapsychology. These concepts are at times confusing and are used interchangeably by various authors. Regardless of what one calls it, what one experiences in a given moment is one's representation as an analyst or a father or a son or daughter, depending on the situation one is in. This paper describes such state-dependent self-representations as an aspect of the self and argues that state-dependent self-representations are probably more clinically relevant and useful in day-to-day practice.
Bound states of Dirac electrons in a graphene-based magnetic quantum dot
Wang, Dali; Jin, Guojun
2009-10-01
We investigate the magnetically confined states of the massless Dirac fermions in a graphene quantum dot formed by the inhomogeneous distributions of the magnetic fields inside and outside the dot. The calculated energy spectrum exhibits quite different features with and without the magnetic field inside the dot. It is found that the degeneracy of the relativistic Landau level with negative angular momenta can be lifted, and this degeneracy breaking can be modulated by the magnetic field inside the dot. Moreover, such a system can form the strongly localized states within the dot and along its boundary, especially with the magnetic field inside the dot.
Directory of Open Access Journals (Sweden)
V.V. Eremenko
2016-06-01
Full Text Available The electron local density of states (LDOS are calculated for graphene with isolated vacancies, divacancies and vacancy group of four nearest-neighbor vacancies. A strong anisotropy of behavior of LDOS near Fermi level is demonstrated for atoms near defect. Effect of next-to-nearest neighbor interaction on the properties of graphene with vacancies is established.
Theoretical study on ground-state proton/H-atom exchange in formic ...
Indian Academy of Sciences (India)
The ground-state triple proton/H-atom transfer (GSTPT/GSTHAT) reactions in HCOOH complexed cyclically with H₂O, CH₃OH, NH₃ and mixed solvents H₂O-NH₃/CH₃ OH-NH₃ were studied byquantum mechanical methods in heptane. The GSTPT/GSTHAT in HCOOH-(H₂O) ₂, HCOOH-(CH₃OH)₂, ...
Energy Technology Data Exchange (ETDEWEB)
Bhattacharya, A.; Talukdar, B. [Department of Physics, Visva-Bharati University, Santiniketan (India); Banerji, G. [Mathematics Department, BU, Burdwan (India); Roy, U. [Theoretical Physics Department, IACS, Calcutta (India)
1998-01-30
A differential equation approach to the perturbation theoretic correction for excited hydrogenic states is introduced. The radial equations for the problem are solved in terms of known transcendental functions and the method to determine the complete primitive is discussed. The constructed perturbative correction to the wavefunction is adapted to evaluate the dipole polarizability of hydrogenic atoms. (author)
Michels, M.A.J.; Suttorp, L.G.
1972-01-01
The inductive contribution to the retarded interatomic potential energy of two atoms in degenerate ground states is calculated up to all multipole orders on the basis of quantum electrodynamics. The result, which is found to have nonretarded character, is written in such a way as to show the
Pulsed excitation of Rydberg-atom-pair states in an ultracold Cs gas
Saßmannshausen, Heiner; Deiglmayr, Johannes
2015-01-01
Pulsed laser excitation of a dense ultracold Cs vapor has been used to study the pairwise interactions between Cs atoms excited to $n$p$_{3/2}$ Rydberg states of principal quantum numbers in the range $n=22-36$. Molecular resonances were observed that correspond to excitation of Rydberg-atom-pair states correlated not only to the $n$p$_{3/2}+n$p$_{3/2}$ dissociation asymptotes, but also to $n$s$_{1/2}+(n+1)$s$_{1/2}$, $n$s$_{1/2}+n'$f$_{j}$, and $(n-4)$f$_{j}+(n-3)$f$_{j}$ $(j=5/2,7/2)$ dissociation asymptotes. These pair resonances are interpreted as arising from dipole-dipole, and higher long-range-interaction terms between the Rydberg atoms on the basis of i) their spectral positions, ii) their response to static and pulsed electric fields, and iii) millimeter-wave spectra between pair states correlated to different pair-dissociation asymptotes. The Rydberg-atom--pair states were found to spontaneously decay by Penning ionization and the dynamics of the ionization process were investigated during the first...
Pregalactic black hole formation with an atomic hydrogen equation of state
Spaans, Marco; Silk, Joseph
2006-01-01
The polytropic equation of state of an atomic hydrogen gas is examined for primordial halos with baryonic masses of M-h similar to 10(7)-10(9) M-circle dot. For roughly isothermal collapse around 10(4) K, we find that line trapping of Ly alpha (H I and He II) photons causes the polytropic exponent
Angular momentum-induced delays in solid-state photoemission enhanced by intra-atomic interactions.
Siek, Fabian; Neb, Sergej; Bartz, Peter; Hensen, Matthias; Strüber, Christian; Fiechter, Sebastian; Torrent-Sucarrat, Miquel; Silkin, Vyacheslav M; Krasovskii, Eugene E; Kabachnik, Nikolay M; Fritzsche, Stephan; Muiño, Ricardo Díez; Echenique, Pedro M; Kazansky, Andrey K; Müller, Norbert; Pfeiffer, Walter; Heinzmann, Ulrich
2017-09-22
Attosecond time-resolved photoemission spectroscopy reveals that photoemission from solids is not yet fully understood. The relative emission delays between four photoemission channels measured for the van der Waals crystal tungsten diselenide (WSe 2 ) can only be explained by accounting for both propagation and intra-atomic delays. The intra-atomic delay depends on the angular momentum of the initial localized state and is determined by intra-atomic interactions. For the studied case of WSe 2 , the photoemission events are time ordered with rising initial-state angular momentum. Including intra-atomic electron-electron interaction and angular momentum of the initial localized state yields excellent agreement between theory and experiment. This has required a revision of existing models for solid-state photoemission, and thus, attosecond time-resolved photoemission from solids provides important benchmarks for improved future photoemission models. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
Entanglement between atomic thermal states and coherent or squeezed photons in a damping cavity
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.
Dillon, Joseph; Yarkony, David R; Schuurman, Michael S
2011-01-28
The quadratic vibronic coupling model is an important computational tool for simulating photoelectron spectra involving strongly coupled electronic states in polyatomic molecules. However, recent work has indicated the need for higher order terms, with most of the initial studies focusing on molecules with symmetry-required degeneracies. In this study we report an extension of our approach for constructing fully quadratic representations of bound electronic states coupled by conical intersections, which allows for the inclusion of higher order terms, demonstrated here employing a quartic expansion. Procedures are developed that eliminate unphysical behavior for large displacements, a problem likely to be an endemic to anharmonic expansions. Following work on representing dissociative electronic states, Lagrange multipliers are used to constrain the constructed representation to reproduce exactly the energy, energy gradients, and∕or derivative couplings at specific points, or nodes, in nuclear coordinate space. The approach is illustrated and systematically studied using the four lowest electronic states of triazolyl, (CH)(2)N(3).
Electron impact excitation of the D states of Mg, Ca and Sr atoms ...
Indian Academy of Sciences (India)
decay of the atom from D → P and then P → S) is required [3,7–9]. ... for the excitation of helium from its ground 1S state to the 3 1D state at 40 eV. We ..... Further, we use for the projectile electron distorted wave function. FDW i(f) the following relativistic form of partial wave expansion: F± ch,µch (kch, r) = 1. (2π)3/2 ∑ κm.
Bound states within the radiation continuum in diffraction gratings and the role of leaky modes
Monticone, Francesco; Alù, Andrea
2017-09-01
We discuss resonant states with diverging Q factor within the radiation continuum based on the anomalous interaction of leaky guided modes and diffracted waves in suitably designed reflection gratings. We show that these trapped optical states can be understood within the framework of leaky-wave theory, which unveils their generation process and dynamics. Our findings reveal an interesting mechanism to realize embedded eigenstates in periodic structures, shedding light on their electromagnetic properties, and offering the possibility to quantitatively predict their occurrence and systematically design optimal structures that support them. The realization of extraordinary optical trapping in open structures may be important for applications that require strongly confined and enhanced fields and high selectivity in angle and frequency.
An Efficient Implementation of Non-Linear Limit State Analysis Based on Lower-Bound Solutions
DEFF Research Database (Denmark)
Damkilde, Lars; Schmidt, Lotte Juhl
2005-01-01
Limit State analysis has been used in design for decades e.g. the yield line theory for concrete slabs or slip line solutions in geotechnics. In engineering practice manual methods have been dominating but in recent years the interest in numerical methods has been increasing. In this respect...... it is mandatory to formulate the methods using the well-known finite element concept in order to interface with other types of analysis....
Energy of van der Waals and dipole-dipole interactions between atoms in Rydberg states
Kamenski, A. A.; Manakov, N. L.; Mokhnenko, S. N.; Ovsiannikov, V. D.
2017-09-01
The van der Waals coefficient C6(θ ;n l J M ) of two like Rydberg atoms in their identical Rydberg states |n l J M 〉 is resolved into four irreducible components called scalar Rs s, axial (vector) Ra a, scalar-tensor Rs T=RT s , and tensor-tensor RT T parts in analogy with the components of dipole polarizabilities. The irreducible components determine the dependence of C6(θ ;n l J M ) on the angle θ between the interatomic and the quantization axes of atoms. The spectral resolution for the biatomic Green's function with account of the most contributing terms is used for evaluating the components Rα β of atoms in their Rydberg series of doublet states of the low angular momenta (2S , 2P , 2D , 2F ). The polynomial presentations in powers of the Rydberg-state principal quantum number n taking into account the asymptotic dependence C6(θ ;n l J M ) ∝n11 are derived for simplified evaluations of irreducible components. Numerical values of the polynomial coefficients are determined for Rb atoms in their n 2S1 /2 , n 2P1 /2 ,3 /2 , n 2D3 /2 ,5 /2 , and n 2F5 /2 ,7 /2 Rydberg states of arbitrary high n . The transformation of the van der Waals interaction law -C6/R6 into the dipole-dipole law C3/R3 in the case of close dipole-connected two-atomic states (the Förster resonance) is considered and the dependencies on the magnetic quantum numbers M and on the angle θ of the constant C3(θ ;n l J M ) are determined together with the ranges of interatomic distances R , where the transformation appears.
Bound states in one-dimensional acoustic parity-time-symmetric lattices for perfect sensing
Energy Technology Data Exchange (ETDEWEB)
Zhao, Degang; Shen, Yaxi; Zhang, Yu; Zhu, Xuefeng, E-mail: xfzhu@hust.edu.cn; Yi, Lin
2016-08-06
In this letter, we study the propagation of acoustic waves through a one-dimensional multilayer structure composed of a thin defect layer sandwiched by two phononic crystals. Two kinds of defect states will generate in band gaps and both of them cause unitary transmission. However, they have very unlike field distributions due to the different contrasted acoustic impedances between the defect layer and its neighboring layers. Spectral positions of transmission peaks can be exactly determined by the resonant phase condition. In a non-dissipative system, these resonant states correspond to single crossing point of two eigenvalues of scattering matrix. When gain and loss are introduced to judiciously construct an acoustic parity-time-symmetric lattice, the crossing point will split into a pair of exceptional points (EPs). Interestingly, the EPs correspond to unidirectional zero reflection that is very sensitive to the thickness of defect layer. Taking advantage of this virtue, a very sensitive acoustic sensor can be designed, which has potentially applications in ultrasonic inspection, noise detection, ultrasonic medicine, etc. - Highlights: • Two kinds of defect states have been systematically studied. • Studying the eigenvalues of scattering matrix for non-dissipative and PT-symmetric system. • Proposing a design of sensitive acoustic sensor.
Depopulation of lowly excited ns-states of Rb colliding with the He atom
Energy Technology Data Exchange (ETDEWEB)
Verma, S.K. [Jagdam College, Chapra (India). Dept. of Physics; Khan, A.A. [ZAI College, Siwan (India). Dept. of Physics; Kumar, V. [Rajendra College, Chapra (India). Dept. of Physics; Kumar, A. [JP University, Chapra (India). Dept. of Physics
1996-03-28
A semiclassical impact-parameter method has been used to study the total depopulation of lowly excited ns-states of the Rb atom colliding with ground-state He in the thermal energy region. A fairly large basis set of STO has been used to generate MO states and then a 14-state calculation has been carried out to evaluate the total as well as individual cross sections for quenching. A comparative study with the previously investigated Li-He and Na-He pairs is also presented. (Author).
Energy Technology Data Exchange (ETDEWEB)
Kano, Naokazu; O' Brien, Nathan J. [Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Uematsu, Ryohei; Ramozzi, Romain; Morokuma, Keiji [Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyou-ku, Kyoto, 606-8103 (Japan)
2017-05-15
The first trihydroborate bearing a pentacoordinated phosphorus atom was synthesized as a new P-B bonded compound. Hydride abstraction of the trihydroborate gave an intermediary dihydroborane, which showed hydroboration reactivity and was trapped with pyridine whilst maintaining the P-B bond. The dihydroborane underwent a rearrangement, which involved a double ring expansion to compensate for the unbalanced coordination states of the phosphorus and boron atoms, to give a new fused bicyclic phosphine-boronate. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)
Accuracy of bound-state form factors extracted from dispersive sum rules
Energy Technology Data Exchange (ETDEWEB)
Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Nuclear Physics Institute, Moscow State University, 119992 Moscow (Russian Federation)], E-mail: dmitri_melikhov@gmx.de; Simula, Silvano [INFN, Sezione di Roma III, Via della Vasca Navale 84, I-00146 Roma (Italy)
2009-02-02
We discuss the extraction of form factors from three-point sum rules making use of a harmonic-oscillator model, where we derive the exact expression for the relevant correlator. We determine the form factor of the ground state by the standard procedures adopted in the method of sum rules, and compare the obtained results with the known exact values. We show that the uncontrollable uncertainty in the extracted value of the form factor is typically much larger than that for the decay constant. In the example considered, we find the uncontrolled systematic error in the extracted form factor to exceed the 10% level.
isospin mixing in the 4He bound state and the nucleon strange form factor
Energy Technology Data Exchange (ETDEWEB)
Rocco Schiavilla
2006-10-11
The contribution of isospin admixtures in the ground state of the {sup 4}He nucleus is studied using wave functions derived from the most modern nuclear interactions, including isospin symmetry breaking terms. The present calculations show that this contribution is larger than previous estimates had indicated. Its effect on parity violating elastic scattering of polarized electrons from {sup 4}He is investigated. In particular, a simple analysis of the recently measured left-right asymmetry at low Q{sup 2} shows that the contribution of these isospin admixtures is of comparable magnitude to that associated with strangeness components in the nucleon electric form factor.
DEFF Research Database (Denmark)
Johnsen, Kristinn; Yngvason, Jakob
1996-01-01
We report on a numerical study of the density matrix functional introduced by Lieb, Solovej, and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes exactly the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge Z...... and the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained...... by other methods. For iron at B=1012 G the ground-state energy differs by less than 2% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative charge...
Aspects of Majorana Bound States in One-Dimensional Systems with and without Time-Reversal Symmetry
DEFF Research Database (Denmark)
Wölms, Konrad Udo Hannes
. In particular they are very important for the closely related phase of one-dimensional topological superconductors with time-reversal symmetry. This phase also exhibits Majorana bound states, and we will study some of its aspects in this thesis. We will discuss some issues related to obtaining this topological......In recent years there has been a lot of interest in topological phases of matter. Unlike conventional phases of matter, topological phases are not distinguished by symmetries, but by so-called topological invariants which have more subtle physical implications. It comes therefore as no surprise...... that for a long time only a few topological phases were studied and those that were, were not studied in the full topological context, which is only known now. One of the topological phases that has been know for a very long time is the quantum Hall eect. The quantum Hall eect is a topological phase in two...
Designing exotic many-body states of atomic spin and motion in photonic crystals
Manzoni, Marco T.; Mathey, Ludwig; Chang, Darrick E.
2017-01-01
Cold atoms coupled to photonic crystals constitute an exciting platform for exploring quantum many-body physics. For example, such systems offer the potential to realize strong photon-mediated forces between atoms, which depend on the atomic internal (spin) states, and where both the motional and spin degrees of freedom can exhibit long coherence times. An intriguing question then is whether exotic phases could arise, wherein crystalline or other spatial patterns and spin correlations are fundamentally tied together, an effect that is atypical in condensed matter systems. Here, we analyse one realistic model Hamiltonian in detail. We show that this previously unexplored system exhibits a rich phase diagram of emergent orders, including spatially dimerized spin-entangled pairs, a fluid of composite particles comprised of joint spin-phonon excitations, phonon-induced Néel ordering, and a fractional magnetization plateau associated with trimer formation. PMID:28272466
Particle beam technology for control of atomic-bonding state in materials
Energy Technology Data Exchange (ETDEWEB)
Ishikawa, Junzo [Kyoto Univ. (Japan). Faculty of Engineering
1997-03-01
The atomic-bonding state in materials can be controlled through `kinetic bonding` process by energetic particle beams which have a sufficient atomic kinetic energy. In order to clarify the `kinetic bonding` process the negative-ion beam deposition is considered as an ideal method because the negative ion has no additional active energies. Sputter type heavy negative-ion sources can be used for this purpose. Carbon films prepared by carbon negative-ion beam deposition have a strong dependency of the film properties on ion beam kinetic energy and have a quite high thermal conductivity which is comparable to that of the IIb diamond at a kinetic energy of 50-100 eV/atom. It suggests that new or metastable materials could be formed through the `kinetic bonding` process. Negative-ion beams can also be used for ion implantation, in which charging problems are perfectly reduced. (author)
Molecular dynamics simulations of a silver atom in water: evidence for a dipolar excitonic state.
Spezia, Riccardo; Nicolas, Cédric; Boutin, Anne; Vuilleumier, Rodolphe
2003-11-14
The properties of a silver atom in bulk water were studied for the first time by molecular dynamics simulations using two complementary mixed quantum-classical approaches. The first one consists of treating by quantum mechanics one electron only, which interacts with a classical silver cation and solvent through one-electron pseudopotentials. The second one is Car-Parrinello molecular dynamics that treats all the valence electrons quantum-mechanically. Very good agreement is obtained between these two methods, and the calculated absorption spectrum of the solvated silver atom agrees very well with experimental data. Both simulations reveal that the silver atom is in the critical region for the appearance of a dipolar excitonic state and exhibits a dipole moment of approximately 2 D with large fluctuations of +/-1 D. The structure of the solvation shell is also analyzed.
Optical frequency synthesizer for precision spectroscopy of Rydberg states of Rb atoms
Watanabe, Naoto; Tamura, Hikaru; Musha, Mitsuru; Nakagawa, Ken'ichi
2017-11-01
We have developed an optical frequency synthesizer for the precision spectroscopy of highly excited Rydberg states of Rb atoms. This synthesizer can generate a widely tunable 480 nm laser light with an optical power of 150 mW and an absolute frequency uncertainty of less than 100 kHz using a high-repetition-rate (325 MHz) Er fiber-based optical frequency comb and a tunable frequency-doubled diode laser at 960 nm. We demonstrate the precision two-photon spectroscopy of the Rydberg states of 87Rb atoms by observing the electromagnetically induced transparency in a vapor cell, and measure the absolute transition frequencies of 87Rb to nD (n = 53-92) and nS (n = 60-90) Rydberg states with an uncertainty of less than 250 kHz. It is the first direct frequency measurements of these transitions using an optical frequency comb.
Detecting correlations in deterministically prepared quantum states with single-atom imaging
Bergschneider, Andrea; Klinkhamer, Vincent M.; Becher, Jan Hendrik; Bommer, Philine L.; Niedermayer, Justin F.; Zuern, Gerhard; Preiss, Philipp M.; Jochim, Selim
2017-04-01
We deterministically prepare quantum states consisting of few fermions in single and double-well potentials. Here we report on a new imaging scheme for 6Lithium with which we detect the correlations of the quantum state on a single-atom level and with spin resolution. The detection method uses fluorescence imaging at high magnetic field where the optical transitions for the used hyperfine states are almost closed. With a high-resolution objective we image about 15 scattered photons per atom on an EMCCD camera. This is sufficient to identify and locate single atoms in our imaging plane. We can perform this scheme in situ or after an expansion in time-of-flight and additionally resolve the spin by subsequently adressing the different hyperfine states. By combining this scheme with our deterministic preparation, we measure the two-point momentum correlations to probe the spatial symmetry of the two-particle wavefunction. The high contrast and the scalability of the detection technique allows us to go beyond measuring two-point correlations and characterize many-body quantum states.
Photon-Mediated Interactions: A Scalable Tool to Create and Sustain Entangled States of N Atoms
Directory of Open Access Journals (Sweden)
Camille Aron
2016-03-01
Full Text Available We propose and study the use of photon-mediated interactions for the generation of long-range steady-state entanglement between N atoms. Through the judicious use of coherent drives and the placement of the atoms in a network of cavity QED systems, a balance between their unitary and dissipative dynamics can be precisely engineered to stabilize a long-range correlated state of qubits in the steady state. We discuss the general theory behind such a scheme and present an example of how it can be used to drive a register of N atoms to a generalized W state and how the entanglement can be sustained indefinitely. The achievable steady-state fidelities for entanglement and its scaling with the number of qubits are discussed for presently existing superconducting quantum circuits. While the protocol is primarily discussed for a superconducting circuit architecture, it is ideally realized in any cavity QED platform that permits controllable delivery of coherent electromagnetic radiation to specified locations.
Albendazole therapy and enteric parasites in United States-bound refugees.
Swanson, Stephen J; Phares, Christina R; Mamo, Blain; Smith, Kirk E; Cetron, Martin S; Stauffer, William M
2012-04-19
Beginning on May 1, 1999, the Centers for Disease Control and Prevention (CDC) recommended presumptive treatment of refugees for intestinal parasites with a single dose of albendazole (600 mg), administered overseas before departure for the United States. We conducted a retrospective cohort study involving 26,956 African and Southeast Asian refugees who were screened by means of microscopical examination of stool specimens for intestinal parasites on resettlement in Minnesota between 1993 and 2007. Adjusted prevalence ratios for intestinal nematodes, schistosoma species, giardia, and entamoeba were calculated among refugees who migrated before versus those who migrated after the CDC recommendation of presumptive predeparture albendazole treatment. Among 4370 untreated refugees, 20.8% had at least one stool nematode, most commonly hookworm (in 9.2%). Among 22,586 albendazole-treated refugees, only 4.7% had one or more nematodes, most commonly trichuris (in 3.9%). After adjustment for sex, age, and region, albendazole-treated refugees were less likely than untreated refugees to have any nematodes (prevalence ratio, 0.19), ascaris (prevalence ratio, 0.06), hookworm (prevalence ratio, 0.07), or trichuris (prevalence ratio, 0.27) but were not less likely to have giardia or entamoeba. Schistosoma ova were identified exclusively among African refugees and were less prevalent among those treated with albendazole (prevalence ratio, 0.60). After implementation of the albendazole protocol, the most common pathogens among 17,011 African refugees were giardia (in 5.7%), trichuris (in 5.0%), and schistosoma (in 1.8%); among 5575 Southeast Asian refugees, only giardia remained highly prevalent (present in 17.2%). No serious adverse events associated with albendazole use were reported. Presumptive albendazole therapy administered overseas before departure for the United States was associated with a decrease in the prevalence of intestinal nematodes among newly arrived African and
Atomic state and characterization of nitrogen at the SiC/SiO2 interface
Xu, Y.; Zhu, X.; Lee, H. D.; Xu, C.; Shubeita, S. M.; Ahyi, A. C.; Sharma, Y.; Williams, J. R.; Lu, W.; Ceesay, S.; Tuttle, B. R.; Wan, A.; Pantelides, S. T.; Gustafsson, T.; Garfunkel, E. L.; Feldman, L. C.
2014-01-01
We report on the concentration, chemical bonding, and etching behavior of N at the SiC(0001)/SiO2 interface using photoemission, ion scattering, and computational modeling. For standard NO processing of a SiC MOSFET, a sub-monolayer of nitrogen is found in a thin inter-layer between the substrate and the gate oxide (SiO2). Photoemission shows one main nitrogen related core-level peak with two broad, higher energy satellites. Comparison to theory indicates that the main peak is assigned to nitrogen bound with three silicon neighbors, with second nearest neighbors including carbon, nitrogen, and oxygen atoms. Surprisingly, N remains at the surface after the oxide was completely etched by a buffered HF solution. This is in striking contrast to the behavior of Si(100) undergoing the same etching process. We conclude that N is bound directly to the substrate SiC, or incorporated within the first layers of SiC, as opposed to bonding within the oxide network. These observations provide insights into the chemistry and function of N as an interface passivating additive in SiC MOSFETs.
Titov, Anatoly V.; Lomachuk, Yuriy V.; Skripnikov, Leonid V.
2014-01-01
A new approach for describing the effective electronic states of "atoms in compounds" to study the properties of molecules and condensed matter which are circumscribed by the operators heavily concentrated in atomic cores is proposed. Among the properties are hyperfine structure, space parity (P) and time reversal invariance (T) nonconservation effects, chemical shifts of x-ray emission lines (XES), M\\"{o}ssbauer effect, etc. Advantage of the approach is that a good quantitative agreement of ...
Gauge invariant description of heavy quark bound states in quantum chromodynamics
Energy Technology Data Exchange (ETDEWEB)
Moore, S.E.
1980-08-01
A model for a heavy quark meson is proposed in the framework of a gauge-invariant version of quantum chromodynamics. The field operators in this formulation are taken to be Wilson loops and strings with quark-antiquark ends. The fundamental differential equations of point-like Q.C.D. are expressed as variational equations of the extended loops and strings. The 1/N expansion is described, and it is assumed that nonleading effects such as intermediate quark pairs and nonplanar gluonic terms can be neglected. The action of the Hamiltonian in the A/sub 0/ = 0 gauge on a string operator is derived. A trial meson wave functional is constructed consisting of a path-averaged string operator applied to the full vacuum. A Gaussian in the derivative of the path location is assumed for the minimal form of the measure over paths. A variational parameter is incorporated in the measure as the exponentiated coefficient of the squared path location. The expectation value of the Hamiltonian in the trial state is evaluated for the assumption that the negative logarithm of the expectation value of a Wilson loop is proportional to the loop area. The energy is then minimized by deriving the equivalent quantum mechanical Schroedinger's equation and using the quantum mechanical 1/n expansion to estimate the effective eigenvalues. It is found that the area law behavior of the Wilson loop implies a nonzero best value of the variational parameter corresponding to a quantum broadening of the flux tube.
Hur, Gwang-Ok
The -kicked rotor is a paradigm of quantum chaos. Its realisation with clouds of cold atoms in pulsed optical lattices demonstrated the well-known quantum chaos phenomenon of 'dynamical localisation'. In those experi ments by several groups world-wide, the £-kicks were applied at equal time intervals. However, recent theoretical and experimental work by the cold atom group at UCL Monteiro et al 2002, Jonckheere et al 2003, Jones et al 2004 showed that novel quantum and classical dynamics arises if the atomic cloud is pulsed with repeating sequences of unequally spaced kicks. In Mon teiro et al 2002 it was found that the energy absorption rates depend on the momentum of the atoms relative to the optical lattice hence a type of chaotic ratchet was proposed. In Jonckheere et al and Jones et al, a possible mechanism for selecting atoms according to their momenta (velocity filter) was investigated. The aim of this thesis was to study the properties of the underlying eigen values and eigenstates. Despite the unequally-spaced kicks, these systems are still time-periodic, so we in fact investigated the Floquet states, which are eigenstates of U(T), the one-period time evolution operator. The Floquet states and corresponding eigenvalues were obtained by diagonalising a ma trix representation of the operator U(T). It was found that the form of the eigenstates enables us to analyse qual itatively the atomic momentum probability distributions, N(p) measured experimentally. In particular, the momentum width of the individual eigen states varies strongly with as expected from the theoretical and ex- perimental results obtained previously. In addition, at specific close to values which in the experiment yield directed motion (ratchet transport), the probability distribution of the individual Floquet states is asymmetric, mirroring the asymmetric N(p) measured in clouds of cesium atoms. In the penultimate chapter, the spectral fluctuations (eigenvalue statis tics) are
Liu, Xiao-Juan; Luo, An; Peng, Zhao-Hui; Jia, Chun-Xia; Jiang, Chun-Lei; Zhou, Bing-Ju
2018-01-01
Considering two two-level atoms initially in Bell state, we send one atom into a vacuum cavity while leaving the other outside, and consider the motion of atom inside the cavity. Using quantum information entropy squeezing theory, the time evolution of the entropy squeezing factor of atom inside the cavity is discussed for two cases, i.e., before and after performing rotation operations and measuring atom outside, the influences of the field mode structure and atomic motions on the atomic entropy squeezing are evaluated. It is shown that atom inside the cavity has no entropy squeezing phenomenon before operating atom outside the cavity. However, the optimal entropy squeezing phenomenon of period T = 2 π/ p emerges and constant entropy squeezing phenomenon can occur by adjusting rotation operation to R( π/4), and setting the field mode structure parameter 0 50, a sustained optimal entropy squeezing state (SOESS) can be generated. We also present the schematic circuit diagram of preparation of SOESS. Our proposal provides a possible way for the initial decoherent state recovering into sustained maximal coherent superposition state of single atom in the quantum noise environment.
Liu, Xiao-Juan; Luo, An; Peng, Zhao-Hui; Jia, Chun-Xia; Jiang, Chun-Lei; Zhou, Bing-Ju
2017-10-01
Considering two two-level atoms initially in Bell state, we send one atom into a vacuum cavity while leaving the other outside, and consider the motion of atom inside the cavity. Using quantum information entropy squeezing theory, the time evolution of the entropy squeezing factor of atom inside the cavity is discussed for two cases, i.e., before and after performing rotation operations and measuring atom outside, the influences of the field mode structure and atomic motions on the atomic entropy squeezing are evaluated. It is shown that atom inside the cavity has no entropy squeezing phenomenon before operating atom outside the cavity. However, the optimal entropy squeezing phenomenon of period T = 2π/p emerges and constant entropy squeezing phenomenon can occur by adjusting rotation operation to R(π/4), and setting the field mode structure parameter 0 50, a sustained optimal entropy squeezing state (SOESS) can be generated. We also present the schematic circuit diagram of preparation of SOESS. Our proposal provides a possible way for the initial decoherent state recovering into sustained maximal coherent superposition state of single atom in the quantum noise environment.
Lifetime determination of the 5d(2) F-3(2) state in barium using trapped atoms
De, S.; Dammalapati, U.; Willmann, L.
2015-01-01
Magneto-optically trapped atoms enable the determination of lifetimes of metastable states and higher lying excited states like the 5d(2) F-3(2) state in barium. The state is efficiently populated by driving strong transitions from metastable states within the cooling cycle of the barium
Formation of H-atom in 2s excited state of proton-lithium and proton ...
Indian Academy of Sciences (India)
Abstract. The differential and total cross-sections have been investigated in the forma- tion of H-atom in the 2s excited state of proton-lithium and proton-sodium scattering by using the Coulomb projected Born (CPB) approximation in the energy range from 50 to. 10,000 keV. The results thus obtained are compared with the ...
Analytical approach to the helium-atom ground state using correlated wavefunctions
Energy Technology Data Exchange (ETDEWEB)
Bhattacharyya, S.; Bhattacharyya, A.; Talukdar, B. [Visvabharati Univ., Santiniketan (India). Dept. of Physics; Deb, N.C. [Indian Association for the Cultivation of Science, Calcutta (India). Dept. of Theoretical Physics
1996-03-14
A realistic three-parameter correlated wavefunction is used to construct an exact analytical expression for the expectation value of the helium-atom Hamiltonian expressed in the interparticle coordinates. The parameters determined variationally are found to satisfy the orbital and correlation cusp conditions to a fair degree of accuracy and yield a value for the ground-state energy which is in good agreement with the exact result. (author).
Arc plasma generator of atomic driver for steady-state negative ion source.
Ivanov, A A; Belchenko, Yu I; Davydenko, V I; Ivanov, I A; Kolmogorov, V V; Listopad, A A; Mishagin, V V; Putvinsky, S V; Shulzhenko, G I; Smirnov, A
2014-02-01
The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.
Cyclotron transitions of bound ions
Bezchastnov, Victor G.; Pavlov, George G.
2017-06-01
A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.
Lucchese, Robert; McCurdy, C. W.; Rescigno, T. N.
2017-04-01
The conversion of resonant metastable states to bound states with changing potential strength in the presence of a Coulomb potential proceeds by a mechanism fundamentally different from the same process in the case of short-range potentials. This phenomenon, which can accompany changes in molecular geometry, is central to the physics of the process of dissociative recombination of electrons with molecular cations. We verify computationally that there is no direct connection between a resonance pole of the S-matrix and the bound state poles for several model problems. We present a detailed analysis of the analytic structure of the scattering matrix in which the resonance pole remains distinct in the complex plane while a new state appears in the bound state spectrum. Nonetheless, as might be expected from quantum-defect theory, there is a close analytic relation between the resonant behavior of scattering at positive energies and the energies of the bound states. This connection allows the width of a resonance at low energies to be calculated directly from the behavior of the quantum defects with changing potential strength or molecular geometry. US-DOE, OBES, Chemical Sciences, Geosciences, and Biosciences Division.
Atomic substitutions in synthetic apatite; Insights from solid-state NMR spectroscopy
Vaughn, John S.
Apatite, Ca5(PO4)3X (where X = F, Cl, or OH), is a unique mineral group capable of atomic substitutions for cations and anions of varied size and charge. Accommodation of differing substituents requires some kind of structural adaptation, e.g. new atomic positions, vacancies, or coupled substitutions. These structural adaptations often give rise to important physicochemical properties relevant to a range of scientific disciplines. Examples include volatile trapping during apatite crystallization, substitution for large radionuclides for long-term storage of nuclear fission waste, substitution for fluoride to improve acid resistivity in dental enamel composed dominantly of hydroxylapatite, and the development of novel biomaterials with enhanced biocompatibility. Despite the importance and ubiquity of atomic substitutions in apatite materials, many of the mechanisms by which these reactions occur are poorly understood. Presence of substituents at dilute concentration and occupancy of disordered atomic positions hinder detection by bulk characterization methods such as X-ray diffraction (XRD) and infrared (IR) spectroscopy. Solid-state nuclear magnetic resonance (NMR) spectroscopy is an isotope-specific structural characterization technique that does not require ordered atomic arrangements, and is therefore well suited to investigate atomic substitutions and structural adaptations in apatite. In the present work, solid-state NMR is utilized to investigate structural adaptations in three different types of apatite materials; a series of near-binary F, Cl apatite, carbonate-hydroxylapatite compositions prepared under various synthesis conditions, and a heat-treated hydroxylapatite enriched in 17O. The results indicate that hydroxyl groups in low-H, near binary F,Cl apatite facilitate solid-solution between F and Cl via column reversals, which result in average hexagonal symmetry despite very dilute OH concentration ( 2 mol percent). In addition, 19F NMR spectra indicate
Energy Technology Data Exchange (ETDEWEB)
Harbola, Varun, E-mail: varunh@iitk.ac.in [Kendriya Vidyalaya (Central School) Indian Institute of Technology, Kanpur-208 016 (India)
2011-11-15
In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron cloud. Our calculation also shows how the Coulomb interaction between electrons affects their distribution. This leads to a physical picture of how electrons are located with respect to each other in these atoms. Finally, we also obtain through our calculations a general formula for the estimate of ground-state energy and radius of two electron atoms and ions with atomic number Z.
Guo, Qiao-Ling; Li, Peng-Cheng; Zhou, Xiao-Xin; Chu, Shih-I.
2018-03-01
We propose an efficient method for the enhancement of below-threshold harmonic generation (BTHG) by mid-infrared laser-driven excited states of a Cs atom. The BTHG is calculated by solving three-dimensional time-dependent Schrödinger equation accurately and efficiently using the time-dependent generalized pseudospectral method. We adopt an excited state as the initial state of a Cs atom. As a result, the BTHG is significantly enhanced by two orders of magnitude compared with the case of the initial ground state. Furthermore, we find that a single vacuum-ultraviolet pulse can be generated by mid-infrared laser-driven excited states by superposing several below-threshold harmonics of a Cs atom. Our finding suggests that the generation of below-threshold harmonics by laser-driven excited states of an atom can provide a powerful methodology for the production of intense vacuum-ultraviolet pulses.
Electron impact ionization of atomic hydrogen from the 1S and 2S states
Energy Technology Data Exchange (ETDEWEB)
Bartschat, K.; Bray, I.
1996-05-01
We present results from R-Matrix with Pseudo-States (RMPS) and Convergent Close-Coupling (CCC) calculations for electron impact total ionization of the 1S and 2S states of atomic hydrogen in the energy region from threshold to 100 eV. Particular attention is given to the near threshold region. We find the results for energies more than 2 eV above threshold to be in excellent agreement with the available experimental data. (authors). 19 refs., 3 figs.
Directory of Open Access Journals (Sweden)
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
Pradas, Marc; Tseluiko, Dmitri; Kalliadasis, Serafim
2011-04-01
We examine the interaction of two-dimensional solitary pulses on falling liquid films. We make use of the second-order model derived by Ruyer-Quil and Manneville [Eur. Phys. J. B 6, 277 (1998); Eur. Phys. J. B 15, 357 (2000); Phys. Fluids 14, 170 (2002)] by combining the long-wave approximation with a weighted residual technique. The model includes (second-order) viscous dispersion effects which originate from the streamwise momentum equation and tangential stress balance. These effects play a dispersive role that primarily influences the shape of the capillary ripples in front of the solitary pulses. We show that different physical parameters, such as surface tension and viscosity, play a crucial role in the interaction between solitary pulses giving rise eventually to the formation of bound states consisting of two or more pulses separated by well-defined distances and traveling at the same velocity. By developing a rigorous coherent-structure theory, we are able to theoretically predict the pulse-separation distances for which bound states are formed. Viscous dispersion affects the distances at which bound states are observed. We show that the theory is in very good agreement with computations of the second-order model. We also demonstrate that the presence of bound states allows the film free surface to reach a self-organized state that can be statistically described in terms of a gas of solitary waves separated by a typical mean distance and characterized by a typical density.
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)
2017-05-15
The quasi-bound states of charged massive scalar fields in the near-extremal charged Reissner-Nordstroem black-hole spacetime are studied analytically. These discrete resonant modes of the composed black-hole-field system are characterized by the physically motivated boundary condition of ingoing waves at the black-hole horizon and exponentially decaying (bounded) radial eigenfunctions at spatial infinity. Solving the Klein-Gordon wave equation for the linearized scalar fields in the black-hole spacetime, we derive a remarkably compact analytical formula for the complex frequency spectrum which characterizes the quasi-bound state resonances of the composed Reissner-Nordstroem-black-hole-charged-massive-scalar-field system. (orig.)
Observation of coherent quench dynamics in a metallic many-body state of fermionic atoms.
Will, Sebastian; Iyer, Deepak; Rigol, Marcos
2015-01-27
Quantum simulation with ultracold atoms has become a powerful technique to gain insight into interacting many-body systems. In particular, the possibility to study nonequilibrium dynamics offers a unique pathway to understand correlations and excitations in strongly interacting quantum matter. So far, coherent nonequilibrium dynamics has exclusively been observed in ultracold many-body systems of bosonic atoms. Here we report on the observation of coherent quench dynamics of fermionic atoms. A metallic state of ultracold spin-polarized fermions is prepared along with a Bose-Einstein condensate in a shallow three-dimensional optical lattice. After a quench that suppresses tunnelling between lattice sites for both the fermions and the bosons, we observe long-lived coherent oscillations in the fermionic momentum distribution, with a period that is determined solely by the Fermi-Bose interaction energy. Our results show that coherent quench dynamics can serve as a sensitive probe for correlations in delocalized fermionic quantum states and for quantum metrology.
Towards hybrid quantum systems: Trapping a single atom near a nanoscale solid-state structure
Directory of Open Access Journals (Sweden)
Tiecke T.G.
2013-08-01
Full Text Available We describe and demonstrate a method to deterministically trap single atoms near nanoscale solid-state objects. The trap is formed by the interference of an optical tweezer and its reflection from the nano object, creating a one-dimensional optical lattice where the first lattice site is at z0 ∼ λ/4 from the surface. Using a tapered optical fiber as the nanoscopic object, we characterize the loading into different lattice sites by means of the AC-Stark shift induced by a guided fiber mode. We demonstrate a loading efficiency of 94(6% into the first lattice site, and measure the cooperativity for the emission of the atom into the guided mode of the nanofiber. We show that by tailoring the dimensions of the nanofiber the distance of the trap to the surface can be adjusted. This method is applicable to a large variety of nanostructures and represents a promising starting point for interfacing single atoms with arbitrary nanoscale solid-state systems.
Coqblin-Schrieffer model for an ultracold gas of ytterbium atoms with metastable state
Kuzmenko, Igor; Kuzmenko, Tetyana; Avishai, Yshai; Jo, Gyu-Boong
2016-03-01
Motivated by the impressive recent advance in manipulating cold ytterbium atoms, we explore and substantiate the feasibility of realizing the Coqblin-Schrieffer model in a gas of cold fermionic 173Yb atoms. Making use of different AC polarizabillity of the electronic ground state (electronic configuration S10) and the long lived metastable state (electronic configuration P30), it is substantiated that the latter can be localized and serve as a magnetic impurity while the former remains itinerant. The exchange mechanism between the itinerant S10 and the localized P30 atoms is analyzed and shown to be antiferromagnetic. The ensuing SU(6) symmetric Coqblin-Schrieffer Hamiltonian is constructed, and, using the calculated exchange constant J , perturbative renormalization group (RG) analysis yields the Kondo temperature TK that is experimentally accessible. A number of thermodynamic measurable observables are calculated in the weak-coupling regime T >TK (using perturbative RG analysis) and in the strong-coupling regime T
Photonic quantum state transfer between a cold atomic gas and a crystal.
Maring, Nicolas; Farrera, Pau; Kutluer, Kutlu; Mazzera, Margherita; Heinze, Georg; de Riedmatten, Hugues
2017-11-22
Interfacing fundamentally different quantum systems is key to building future hybrid quantum networks. Such heterogeneous networks offer capabilities superior to those of their homogeneous counterparts, as they merge the individual advantages of disparate quantum nodes in a single network architecture. However, few investigations of optical hybrid interconnections have been carried out, owing to fundamental and technological challenges such as wavelength and bandwidth matching of the interfacing photons. Here we report optical quantum interconnection of two disparate matter quantum systems with photon storage capabilities. We show that a quantum state can be transferred faithfully between a cold atomic ensemble and a rare-earth-doped crystal by means of a single photon at 1,552 nanometre telecommunication wavelength, using cascaded quantum frequency conversion. We demonstrate that quantum correlations between a photon and a single collective spin excitation in the cold atomic ensemble can be transferred to the solid-state system. We also show that single-photon time-bin qubits generated in the cold atomic ensemble can be converted, stored and retrieved from the crystal with a conditional qubit fidelity of more than 85 per cent. Our results open up the prospect of optically connecting quantum nodes with different capabilities and represent an important step towards the realization of large-scale hybrid quantum networks.
2002-01-01
This experiment uses a magnetic spectrometer to search for monoenergetic @g and @p@+ transitions between bound N&bar.N states. The spectrometer is instrumented with drift chambers (NDC, RDC and PDC), proportional wire chambers (A-E), and various thin scintillation counters (S,M,G,AH,V,Q,D,E and PH) f purposes, as shown in the accompanying drawing.\\\\ \\\\ Gamma-rays produced in the LH^2 target are materialized by a 10\\% converter located in the B chamber with an acceptance (@D@W/4@p) of @=2-6x10|-|3 (100-400 MeV) and 6x10|-|3 ($>$400 MeV). Trajectories of bent electron-positron pairs and @p@+ are measured in the A-E~chambers. Trajectories of less frequent high energy penetrating tracks, as well as the remaining associated charged annihilation products exiting the target, are measured in the drift chamber system. \\\\ \\\\ The resultant energy resolution (@DE/E) is better than 1,5\\% R.M.S. over the full range of energies studied. To illustrate the sensitivity of this experiment, a @g line at 300 MeV produced at t...
Ghorbel, Imen; Amara, Ibtissem Ben; Ktari, Naourez; Elwej, Awatef; Boudawara, Ons; Boudawara, Tahia; Zeghal, Najiba
2016-12-01
Accumulation of aluminium and acrylamide in food is a major source of human exposure. Their adverse effects are well documented, but there is no information about the health problems arising from their combined exposure. The aim of the present study was to examine the possible neurotoxic effects after co-exposure of pregnant and lactating rats to aluminium and acrylamide in order to evaluate redox state, cholinergic function and membrane-bound ATPases in the cerebellum of adult rats and their progeny. Pregnant female rats have received aluminium (50 mg/kg body weight) via drinking water and acrylamide (20 mg/kg body weight) by gavage, either individually or in combination from the 14th day of pregnancy until day 14 after delivery. Exposure to these toxicants provoked an increase in malondialdehyde (MDA) and advanced oxidation protein product (AOPP) levels and a decrease in SOD, CAT, GPx, Na+K+-ATPase, Mg2+-ATPase and AChE activities in the cerebellum of mothers and their suckling pups. A reduction in GSH, NPSH and vitamin C levels was also observed. These changes were confirmed by histological results. Interestingly, co-exposure to these toxicants exhibited synergism based on physical and biochemical variables in the cerebellum of mothers and their progeny.
Energy Technology Data Exchange (ETDEWEB)
Christiansen, H.R. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]. E-mail: hugo@cbpf.br; Cima, O.M. Del [Universidade Catolica de Petropolis, RJ (Brazil). Grupo de Fisica Teorica]. E-mail: delcima@gft.ucp.br; Ferreira Junior, M.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]|[Maranhao Univ., Sao Luis, MA (Brazil). Dept. de Fisica]. E-mail: manojr@cbpf.br; Helayel-Neto, J.A. [Universidade Catolica de Petropolis, RJ (Brazil). Grupo de Fisica Teorica]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]. E-mail: helayel@gft.ucp.br
2001-08-01
We consider a parity-preserving QED{sub 3} model with spontaneous breaking of the gauge symmetry as a framework for the evaluation of the electron-electron interaction potential underlying high-T{sub e} superconductivity. The fact that resulting potential, - C{sub s} K{sub o} (Mr), is non-confining and weak (in the sense of Kato) strongly suggests the mechanism of pair-condensation. This potential, compatible with an s-wave order parameters, is then applied to the Schrodinger equation for the sake of numerical calculations, thereby enforcing the existence of bound states. The results worked out by means of our theoretical framework are checked by considering a number of phenomenological data extracted from different copper oxide superconductors. The agreement may motivate a deeper analysis of our model viewing an application to quasi-planar cuprate superconductors. The data analyzed here suggest an energy scale of 1-10 meV for the breaking of the U(1)-symmetry. (author)
Sharma, Natasha
2016-01-01
The excellent particle identification capabilities of the ALICE detector, using the time projection chamber and the time-of-flight detector, allow the detection of light nuclei and anti-nuclei. Furthermore, the high tracking resolution provided by the inner tracking system enables the separation of primary nuclei from those coming from the decay of heavier systems. This allows for the reconstruction of decays such as the hypertriton mesonic weak decay ($^3_{\\Lambda}$H$\\rightarrow ^3$He + $\\pi^-$), the decay of a hypothetical bound state of a $\\Lambda$n into a deuteron and pion or the H-dibaryon decaying into a $\\Lambda$, a proton and a $\\pi^{-}$. An overview of the production of stable nuclei and anti-nuclei in proton-proton, proton-lead and, in particular, lead-lead collisions is presented. Hypernuclei production rates in Pb--Pb are also shown, together with the upper limits estimated on the production of hypothetical exotica candidates. The results are compared with predictions for the production in thermal...
National Research Council Canada - National Science Library
Ballester Pla, Coralio; Hernández, Penélope
2012-01-01
The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models...
[Atomic force microscopy monitoring of temperature dependence of cytochrome BM3 oligomeric state].
Bukharina, N S; Ivanov, Iu D; Pleshakova, T O; Frantsuzov, P A; Ivanova, N D; Krokhin, N V; Petushkova, N A; Archakov, A I
2015-01-01
The change in temperature is one of the factors affecting the activity of enzymes. In this work thermal denaturation and aggregation of cytochrome P450 BM3 were studied by atomic force microscopy. To determine specific temperature transitions the fluorescence analysis was used. In the low melting temperature range, 10-33 degrees C, a decrease in the fluorescence intensity of aromatic residues was observed with an increase in the fluorescence intensity of flavin groups. Protein melting in this range indicated three narrow S-shaped cooperative transitions at temperatures 16, 22 and 29 degrees C. Atomic force microscopy analysis in this temperature range showed that the shape of BM3 molecules remained globular in the form of compact objects (heights h < 7 nm, lateral dimensions d < 50 nm), but protein oligomeric state changed. The first two transitions were accompanied by a decrease in the degree of oligomerization and the third one was accompanied by its increase.
Gutiérrez-Rodríguez, A
2003-01-01
A bound on the nu /sup tau / magnetic moment is calculated through the reaction e/sup +/e/sup -/ to nu nu gamma at the Z/sub 1/-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle phi of the model in the allowed experimental range for this parameter. (31 refs).
Bounding Species Distribution Models
Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].
A Probabilistic Finite State Logic Machine Realized Experimentally on a Single Dopant Atom.
Fresch, Barbara; Bocquel, Juanita; Rogge, Sven; Levine, R D; Remacle, F
2017-03-08
Exploiting the potential of nanoscale devices for logic processing requires the implementation of computing functionalities departing from the conventional switching paradigm. We report on the design and the experimental realization of a probabilistic finite state machine in a single phosphorus donor atom placed in a silicon matrix electrically addressed and probed by scanning tunneling spectroscopy (STS). The single atom logic unit simulates the flow of visitors in a maze whose topology is determined by the dynamics of the electronic transport through the states of the dopant. By considering the simplest case of a unique charge state for which three electronic states can be resolved, we demonstrate an efficient solution of the following problem: in a maze of four connected rooms, what is the optimal combination of door opening rates in order to maximize the time that visitors spend in one specific chamber? The implementation takes advantage of the stochastic nature of electron tunneling, while the output remains the macroscopic current whose reading can be realized with standard techniques and does not require single electron sensitivity.
Nishiyama, Yoshihiro
2008-05-01
The low-lying spectrum of the three-dimensional Ising model is investigated numerically; we made use of an equivalence between the excitation gap and the reciprocal correlation length. In the broken-symmetry phase, the magnetic excitations are attractive, forming a bound state with an excitation gap m_{2} (mass-gap ratio as m_{2}/m_{1}=1.84(3) .
Experimental study of bound states in ^{12}Be through low-energy ^{11}Be(d,p)-transfer reactions
DEFF Research Database (Denmark)
Johansen, Jacob S.; Bildstein, V.; Borge, M. J. G.
2013-01-01
The bound states of 12Be have been studied through a 11Be(d,p)12Be transfer reaction experiment in inverse kinematics. A 2.8 MeV/u beam of 11Be was produced using the REX-ISOLDE facility at CERN. The outgoing protons were detected with the T-REX silicon detector array. The MINIBALL germanium arra...
DEFF Research Database (Denmark)
Naqvi, Mohsin M; Heiðarsson, Pétur Orri; Otazo, Mariela R
2015-01-01
were reconstructed through hidden Markov model analysis. Unlike what has been observed with the Ca(2+)-bound state, the presence of Mg(2+) allows both the N- and C-domain to fold through all-or-none transitions with similar refolding rates. In the absence of divalent ions, NCS-1 unfolds and refolds...
Wigner’s phase-space function and atomic structure: II. Ground states for closed-shell atoms
DEFF Research Database (Denmark)
Springborg, Michael; Dahl, Jens Peder
1987-01-01
display and analyze the function for the closed-shell atoms helium, beryllium, neon, argon, and zinc in the Hartree-Fock approximation. The quantum-mechanical exact results are compared with those obtained with the approximate Thomas-Fermi description of electron densities in phase space....
Properties of ground states of atomic nuclei in self-consistent theory of finite fermi-system
Energy Technology Data Exchange (ETDEWEB)
Sapershtejn, Eh.E.; Khodel' , V.A. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)
1983-05-01
Ground states of atomic nuclei are described within the framework of the self-consistent theory of finite Fermi systems. The developed approach is compared with the Hartree-Fock method with effective forces.
Schreck, Simon; Pietzsch, Annette; Kennedy, Brian; Såthe, Conny; Miedema, Piter S; Techert, Simone; Strocov, Vladimir N; Schmitt, Thorsten; Hennies, Franz; Rubensson, Jan-Erik; Föhlisch, Alexander
2016-01-29
Thermally driven chemistry as well as materials' functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are lacking. Here we demonstrate how sub-natural linewidth resonant inelastic soft x-ray scattering at vibrational resolution is utilized to determine ground state potential energy surfaces locally and detect long-range changes of the potentials that are driven by local modifications. We show how the general concept is applicable not only to small isolated molecules such as O2 but also to strongly interacting systems such as the hydrogen bond network in liquid water. The weak perturbation to the potential energy surface through hydrogen bonding is observed as a trend towards softening of the ground state potential around the coordinating atom. The instrumental developments in high resolution resonant inelastic soft x-ray scattering are currently accelerating and will enable broad application of the presented approach. With this multidimensional potential energy surfaces that characterize collective phenomena such as (bio)molecular function or high-temperature superconductivity will become accessible in near future.
Norris, D G; Orozco, L A; Barberis-Blostein, P; Carmichael, H J; 10.1103/PhysRevA.86.053816
2012-01-01
The spontaneous creation and persistence of ground-state coherence in an ensemble of intracavity Rb atoms has been observed as a quantum beat. Our system realizes a quantum eraser, where the detection of a first photon prepares a superposition of ground-state Zeeman sublevels, while detection of a second erases the stored information. Beats appear in the time-delayed photon-photon coincidence rate (intensity correlation function). We study the beats theoretically and experimentally as a function of system parameters, and find them remarkably robust against perturbations such as spontaneous emission. Although beats arise most simply through single-atom-mediated quantum interference, scattering pathways involving pairs of atoms interfere also in our intracavity experiment. We present a detailed model which identifies all sources of interference and accounts for experimental realities such as imperfect pre-pumping of the atomic beam, cavity birefringence, and the transit of atoms across the cavity mode.
Plasma Effects On Atomic Data For The K-Vacancy States Of Highly Charged Iron Ions
Deprince, J; Fritzsche, S; Kallman, T. R.; Palmeri, P; Quinet, Pascal
2017-01-01
The main goal of the present work is to estimate the effects of plasma environment on the atomic parameters associated with the K-vacancy states in highly charged iron ions within the astrophysical context of accretion disks around black holes. In order to do this, multiconfiguration Dirac-Fock computations have been carried out by considering a time averaged Debye-H\\"uckel potential for both the electron-nucleus and electron-electron interactions. In the present paper, a first sample of resu...
Existence of a ground state for the confined hydrogen atom in non-relativistic QED
DEFF Research Database (Denmark)
Amour, Laurent; Faupin, Jeremy
2008-01-01
We consider a system of a hydrogen atom interacting with the quantized electromagnetic field. Instead of fixing the nucleus, we assume that the system is confined by its center of mass. This model is used in theoretical physics to explain the Lamb-Dicke effect. After a brief review...... of the literature, we explain how to verify some properly chosen binding conditions which, by [25], lead to the existence of a ground state for our model, and for all values of the fine-structure constant...
Laughlin-like States in Bosonic and Fermionic Atomic Synthetic Ladders
Directory of Open Access Journals (Sweden)
Marcello Calvanese Strinati
2017-06-01
Full Text Available The combination of interactions and static gauge fields plays a pivotal role in our understanding of strongly correlated quantum matter. Cold atomic gases endowed with a synthetic dimension are emerging as an ideal platform to experimentally address this interplay in quasi-one-dimensional systems. A fundamental question is whether these setups can give access to pristine two-dimensional phenomena, such as the fractional quantum Hall effect, and how. We show that unambiguous signatures of bosonic and fermionic Laughlin-like states can be observed and characterized in synthetic ladders. We theoretically diagnose these Laughlin-like states focusing on the chiral current flowing in the ladder, on the central charge of the low-energy theory, and on the properties of the entanglement entropy. Remarkably, Laughlin-like states are separated from conventional liquids by Lifschitz-type transitions, characterized by sharp discontinuities in the current profiles, which we address using extensive simulations based on matrix-product states. Our work provides a qualitative and quantitative guideline towards the observability and understanding of strongly correlated states of matter in synthetic ladders. In particular, we unveil how state-of-the-art experimental settings constitute an ideal starting point to progressively tackle two-dimensional strongly interacting systems from a ladder viewpoint, opening a new perspective for the observation of non-Abelian states of matter.
Mizukoshi, Yumiko; Takeuchi, Koh; Arutaki, Misa; Tokunaga, Yuji; Takizawa, Takeshi; Hanzawa, Hiroyuki; Shimada, Ichio
2016-11-14
The thermodynamic properties of a ligand in the bound state affect its binding specificity. Strict binding specificity can be achieved by introducing multiple spatially defined interactions, such as hydrogen bonds and van der Waals interactions, into the ligand-receptor interface. These introduced interactions are characterized by restricted local dynamics and improved surface complementarity in the bound state. In this study, we experimentally evaluated the local dynamics and the surface complementarity of weak-affinity ligands in the receptor-bound state by forbidden coherence transfer analysis in free-bound exchange systems (Ex-FCT), using the interaction between a ligand, a myocyte-enhancer factor 2A (MEF2A) docking peptide, and a receptor, p38α, as a model system. The Ex-FCT analyses successfully provided information for the rational design of a ligand with higher affinity and preferable thermodynamic properties for p38α. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Directory of Open Access Journals (Sweden)
Z. T. Jiang
2016-12-01
Full Text Available We theoretically investigate the electron transport properties of a wheel-like quantum dot (QD structure with a central QD side coupled with many pairs of QD and Majorana bound states (MBSs by using the nonequilibrium Green’s function method. For clarity, we concentrate our researches on the parameter regime where interdot couplings is much smaller than the inter-MBS and MBS-QD couplings, which ensures the conductance peaks induced by them distinguishable. In the absence of the interdot couplings among the side QDs, the increase of the MBS-QD pair number is equivalent to the increase of the interdot coupling in the QD structure including one central QD and one MBS-QD pair. It is shown that as a response the interval between two side symmetrical peaks will be enlarged, and the MBS-QD couplings will bring into being a zero-bias conductance peak which can be split into two symmetrical sub-peaks by the nonzero inter-MBS couplings. In the presence of the interdot couplings among the side QDs, they make serious influences on the conductance peaks determined by the QD energy levels, and still comes into being the zero-bias conductance peak due to the MBS-QD couplings, yet which is split into two asymmetrical sub-peaks under the influences of the nonzero inter-MBS couplings. Moreover, we conduct a detailed investigation into how the couplings among side QDs affect the transport properties, clearly exposing the underneath mechanics responsible for producing these phenomena. Finally, a generalization is made so as to discuss the geometry universality and the parameter universality of the conclusion drawn in the present work. It should be emphasized that this research will be helpful for a comprehensive understanding the quantum transport through the QD systems coupled with MBSs.
Quasi-bound alpha resonant states populated by the {sup 12}C({sup 6}Li, d) reaction
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, M.R.D.; Borello-Lewin, T.; Miyake, H.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Souza, M.A. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Cunsolo, A.; Cappuzzello, F.; Foti, A.; Agodi, C.; Cavallaro, M. [Istituto Nazionale di Fisica Nucleare (LNS/INFN), Catania (Italy). Lab. Nazionali del Sud; Ukita, G.M. [Universidade de Santo Amaro (UNISA), Sao Paulo, SP (Brazil). Faculdade de Psicologia
2012-07-01
Full text: The alpha cluster phenomenon in the light nuclei structure has been the subject of a long time investigation since the proposal of the Ikeda diagrams [1]. The main purpose of the research program in progress is the investigation of this phenomenon in (x{alpha}) and (x{alpha}+n) nuclei through the ({sup 6}Li, d) alpha transfer reaction [2-4]. Alpha resonant states around the (4{alpha}) threshold in the nucleus {sup 16}O are the focus of the present contribution. In fact, the importance of these resonances at the elements production in stars is recognized, as primarily pointed out by Hoyle in {sup 12}C [6]. The existence of a rotational band with the {alpha} +{sup 12} C (Hoyle) cluster state structure was recently demonstrated by Ohkubo and Hirabayashi [6]. In order to explore this region of interest, measurements of the {sup 12}C({sup 6}Li, d){sup 16}O reaction up to 17 MeV of excitation at an incident energy of 25.5 MeV, have been performed employing the Sao Paulo Pelletron-Enge Split-Pole facility and the nuclear emulsion detection technique (plates Fuji G6B, 50 {mu}m thick). Spectra associated with six scattering angles, from 5 deg to 29 deg in the laboratory frame, each one 50 cm along the focal surface, were measured. Several narrow resonances with a quasi-bound behavior embedded in the continuum were detected and the resolution of 25 keV allowed for the separation of doublets not resolved before [7,8]. The absolute cross sections and the respective deuteron angular distributions were determined and the analysis is in progress. [1] K. Ikeda et al., Prog. Theor. Phys. Suppl. E 68, 464 (1968); H. Horiuchi, K. Ikeda, and Y. Suzuki, ibid. 44, 225 (1978). [2] M.R.D.Rodrigues et al., in12th International Conference on Nuclear Reaction Mechanism, Varenna, Italy, edited by F. Cerutti and A. Ferrari , CERN Proceedings, 2010-2, pp. 331- 335. [3] T. Borello-Lewin et al., Proceedings of SOTANCP2, Brussels, Belgium 2010, edited by P. Descouvemount et al., Int. J
Entanglement of mixed quantum states for qubits and qudit in double photoionization of atoms
Energy Technology Data Exchange (ETDEWEB)
Chakraborty, M., E-mail: bminakshi@yahoo.com [Department of Physics, Asansol Girls’ College, Asansol 713304 (India); Sen, S. [Department of Physics, Triveni Devi Bhalotia College, Raniganj 713347 (India)
2015-08-15
Highlights: • We study tripartite entanglement between two electronic qubits and an ionic qudit. • We study bipartite entanglement between any two subsystems of a tripartite system. • We have presented a quantitative application of entangled properties in Neon atom. - Abstract: Quantum entanglement and its paradoxical properties are genuine physical resources for various quantum information tasks like quantum teleportation, quantum cryptography, and quantum computer technology. The physical characteristic of the entanglement of quantum-mechanical states, both for pure and mixed, has been recognized as a central resource in various aspects of quantum information processing. In this article, we study the bipartite entanglement of one electronic qubit along with the ionic qudit and also entanglement between two electronic qubits. The tripartite entanglement properties also have been investigated between two electronic qubits and an ionic qudit. All these studies have been done for the single-step double photoionization from an atom following the absorption of a single photon without observing spin orbit interaction. The dimension of the Hilbert space of the qudit depends upon the electronic state of the residual photoion A{sup 2+}. In absence of SOI, when Russell–Saunders coupling (L–S coupling) is applicable, dimension of the qudit is equal to the spin multiplicity of A{sup 2+}. For estimations of entanglement and mixedness, we consider the Peres–Horodecki condition, concurrence, entanglement of formation, negativity, linear and von Neumann entropies. In case of L–S coupling, all the properties of a qubit–qudit system can be predicted merely with the knowledge of the spins of the target atom and the residual photoion.
Ground and excited states for exotic three-body atomic systems
Directory of Open Access Journals (Sweden)
Gasaneo G.
2010-04-01
Full Text Available An Angular Correlated Conﬁguration Interaction method is extended and applied to exotic threebody atomic systems with general masses. A recently proposed angularly correlated basis set is used to construct, simultaneously and with a single diagonalization, ground and excited states wave functions which: (i satisfy exactly Kato cusp conditions at the two-body coalescence points; (ii have only linear parameters; (iii show a fast convergency rate for the energy; (iv form an orthogonal set. The eﬃciency of the construction is illustrated by the study a variety of three-body atomic systems [m1− m2− m3z3+ ] with two negatively charged light particles, with 123 diverse masses m1− and m2−, and a heavy positively charged nucleus m3z3+. The calculated ground 11S and several excited n1,3S state energies are compared with those given in the literature, when available. We also present a short discussion on the critical charge necessary to get a stable three-body system supporting two electrons, an electron and a muon, or two muons.
Systematics of ground state multiplets of atomic nuclei in the delta-interaction approach
Energy Technology Data Exchange (ETDEWEB)
Imasheva, L. T.; Ishkhanov, B. S.; Stepanov, M. E., E-mail: stepanov@depni.sinp.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Tretyakova, T. Yu. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)
2015-12-15
Pairing forces between nucleons in an atomic nucleus strongly influence its structure. One of the manifestations of pair interaction is the ground state multiplet (GSM) formation in the spectrum of low-lying excited states of even–even nuclei. The value of GSM splitting is determined by the value of pair interaction of nucleons; for each isotope, it can be estimated on the basis of experimental nuclear masses. The quality of this estimate is characterized by the degree of reproduction of GSM levels in the nucleus. The GSM systematics in even–even nuclei with a pair of identical nucleons in addition to the filled nuclear core is considered on the basis of delta interaction.
Search for Long-Lived States of $\\pi^+\\pi^-$ Atoms : Addendum to the DIRAC Proposal
Adeva, B; Anania, A; Aogaki, S; Augsten, K; Batyuk, P; Benelli, A; Brekhovskikh, V; Cechak, T; Chiba, M; Ciortea, C; Curceanu, C; Doskarova, P; Dudarev, A; Dumitriu, D; Drijard, D; Fluerasu, D; Gortchakov, O; Gritsay, K; Guaraldo, C; Gugiu, M; Hansroul, M; Hosek, R; Hons, Z; Iwashita, Y; Karpukhin, V; Kluson, J; Kobayashi, M; Kruglov, V; Kruglova, L; Kulikov, A; Kulish, E; Kuptsov, A; Lamberto, A; Lednicky, R; Martincik, J; Nemenov, L; Nikitin, M; Okada, K; Pentia, M; Plo, M; Prusa, P; Rappazzo, G; Ryazantsev, A; Romero, A; Ronzhin, V; Rykalin, V; Saborido, J; Schacher, J; Shlyapnikov, P; Smolik, J; Takeutchi, F; Trojek, T; Urban, T; Vrba, T; Vazquez, P; Yazkov, V; Yoshimura, Y; Zhabitsky, M; Zrelov, P
2012-01-01
The proposed experiment is a further development of the DIRAC experiment already running at CERN PS. The observation of long-lived (metastable) states of $\\pi^+\\pi^-$ atoms ($A_{2\\pi}$) will be performed with the same setup. This observation opens a possibility to measure the energy difference between $ns$ and $np$ states and to determine the value of the combination $2a_0+a_2$ of S-wave $\\pi\\pi$ scattering lengths in a model-independent way. In combination with the $A_{2\\pi}$ lifetime measurement providing the value $|a_0-a_2|$ DIRAC is in the position to get $a_0$ and $a_2$ separately on the basis of $A_{2\\pi}$ data only.
Yokoyama, Tomohiro; Reutlinger, Johannes; Belzig, Wolfgang; Nazarov, Yuli V.
2017-01-01
We consider the spectrum of Andreev bound states (ABSs) in an exemplary four-terminal superconducting structure where four chaotic cavities are connected by quantum point contacts to the terminals and to each other forming a ring. We nickname the resulting device 4T-ring. Such a tunable device can be realized in a 2D electron gas-superconductor or a graphene-based hybrid structure. We concentrate on the limit of a short structure and large conductance of the point contacts where there are many ABS in the device forming a quasicontinuous spectrum. The energies of the ABS can be tuned by changing the superconducting phases of the terminals. We observe the opening and closing of gaps in the spectrum upon changing the phases. This concerns the usual proximity gap that separates the levels from zero energy as well as less usual "smile" gaps that split the levels of the quasicontinuous spectrum. We demonstrate a remarkable crossover in the overall spectrum that occurs upon changing the ratio of conductances of the inner and outer point contacts. At big values of the ratio (closed limit), the levels exhibit a generic behavior expected for the spectrum of a disordered system manifesting level repulsion and Brownian "motion" upon changing the phases. At small values of the ratio (open limit), the levels are squeezed into narrow bunches separated by wide smile gaps. Each bunch consists of almost degenerate ABS formed by Andreev reflection between two adjacent terminals. We study in detail the properties of the spectrum in the limit of a small ratio, paying special attention to the crossings of bunches. We distinguish two types of crossings: (i) with a regular phase dependence of the levels and (ii) crossings where the Brownian motion of the levels leads to an apparently irregular phase dependence. We work out a perturbation theory that explains the observations both at a detailed level of random scattering in the device and at a phenomenological level of positively defined
Sinninghe Damsté, J.S.; Leeuw, J.W. de
1990-01-01
This paper reviews the developments of the 1980s in the characterisation of organically-bound sulphur in the geosphere and summarises the geochemical significance of the results obtained by these studies. The identification of more than 1500 novel OSC (organic sulphur compounds) with structures
Electron impact excitation cross sections and rates from the ground state of atomic calcium
Samson, A M
2001-01-01
New R-matrix calculations are presented for electron excitation of atomic calcium. The target state expansion includes 22 states: 4s sup 2 sup 1 S; 4snl sup 1 sup , sup 3 L, where nl is 3d, 4p, 5s, 5p, 4d and 4f; 3d4p sup 1 sup , sup 3 P,D,F; and 4p sup 2 sup 3 P, sup 1 D, sup 1 S terms. The calculation is in LS coupling, and configuration interaction involving 3p subshell correlation is included. Electron impact excitation cross sections from the 4s sup 2 ground state to the next 10 states are tabulated for low energies, and thermally averaged effective collision strengths are tabulated over a range of electron temperatures from 1000 to 10,000 K. Comparisons are made with previous cross sections calculations for the 4s sup 2 -4s4p sup 3 P deg. transition; excellent agreement is found with experimentally derived rates for 4s sup 2 -4s4p sup 1 P deg
Vyvey, K; Cottenier, S; Balabanski, D L; Coulier, N; Coussement, R; Georgiev, G; Lépine-Szily, A; Ternier, S; Teughels, S
2001-01-01
An extension of the time-integrated atomic decoupling technique to measure g-factors of (sub)nanosecond isomers and/or the magnetic hyperfine field induced by highly excited atomic electrons on nuclei recoiling into vacuum is discussed. A high average field B sub h sub f =1080 sub - sub 1 sub 7 sub 5 sup + sup 2 sup 7 sup 0 T and an average atomic spin J=2.7(2) is deduced using the known magnetic moment of a 4.05(7) mu s isomer in sup 6 sup 9 Ge. Such high magnetic fields allow g-factor measurements of (sub)nanosecond states. Ab initio calculations show that the combination of a high average magnetic hyperfine field and a high average atomic spin is only possible if a considerable fraction of the ions is in a metastable excited state.
DEFF Research Database (Denmark)
Kutchinsky, Jonatan; Taboryski, Rafael Jozef; Sørensen, C B
2001-01-01
We report measurements on three-terminal superconductor-semiconductor-superconductor injection devices demonstrating enhancement of the supercurrent by injection from a superconducting injector electrode. Two other electrodes were used to form the detector junction. Applying a small voltage to th...... of enhancement of the supercurrent by non-equilibrium injection into bound supercurrent-carrying Andreev states. The effect persists to temperatures where the equilibrium supercurrent has vanished. (C) 2001 Elsevier Science B.V. All rights reserved....
A multi-state modified embedded atom method potential for titanium
Gibson, J. S.; Srinivasan, S. G.; Baskes, M. I.; Miller, R. E.; Wilson, A. K.
2017-01-01
The continuing search for broadly applicable, predictive, and unique potential functions led to the invention of the multi-state modified embedded atom method (MS-MEAM) (Baskes et al 2007 Phys. Rev. B 75 094113). MS-MEAM replaced almost all of the prior arbitrary choices of the MEAM electron densities, embedding energy, pair potential, and angular screening functions by using first-principles computations of energy/volume relationships for multiple reference crystal structures and transformation paths connecting those reference structures. This strategy reasonably captured diverse interactions between atoms with variable coordinations in a face-centered-cubic (fcc)-stable copper system. However, a straightforward application of the original MS-MEAM framework to model technologically useful hexagonal-close-packed (hcp) metals proved elusive. This work describes the development of an hcp-stable/fcc-metastable MS-MEAM to model titanium by introducing a new angular function within the background electron density description. This critical insight enables the titanium MS-MEAM potential to reproduce first principles computations of reference structures and transformation paths extremely well. Importantly, it predicts lattice and elastic constants, defect energetics, and dynamics of non-ideal hcp and liquid titanium in good agreement with first principles computations and corresponding experiments, and often better than the three well-known literature models used as a benchmark. The titanium MS-MEAM has been made available in the Knowledgebase of Interatomic Models (https://openkim.org/) (Tadmor et al 2011 JOM 63 17).
Energy Technology Data Exchange (ETDEWEB)
Jungk, R.
1991-01-01
Illustrous, eloquent, and yet easy to read for the interested layman, the book begins with alleged deplorable conditions at the reprocessing centra La Hague, portrays, amongst other things, the spying on and supervision of persons in the nuclear field and in research, the misuse of fissile material, and threats and blackmail as a consequence thereof, human error as a cause of accidents, and it concludes with a nonviolent new International against the state and atomic energy, against technological tyranny. Titles of chapters: The hard road; radiation feed; the gamblers; homo atomicus; the intimidated; the ''proliferators''; nuclear terrorists; those supervised; the smooth road. It remains an open question whether the book contributes to defusing the nuclear controversy - in the book almost an ideology - and to bringing the two sides closer together. (HP).
Strong light-matter coupling from atoms to solid-state systems
2014-01-01
The physics of strong light-matter coupling has been addressed in different scientific communities over the last three decades. Since the early eighties, atoms coupled to optical and microwave cavities have led to pioneering demonstrations of cavity quantum electrodynamics, Gedanken experiments, and building blocks for quantum information processing, for which the Nobel Prize in Physics was awarded in 2012. In the framework of semiconducting devices, strong coupling has allowed investigations into the physics of Bose gases in solid-state environments, and the latter holds promise for exploiting light-matter interaction at the single-photon level in scalable architectures. More recently, impressive developments in the so-called superconducting circuit QED have opened another fundamental playground to revisit cavity quantum electrodynamics for practical and fundamental purposes. This book aims at developing the necessary interface between these communities, by providing future researchers with a robust conceptu...
An all-solid-state laser source at 671 nm for cold atom experiments with lithium
Eismann, Ulrich; Canalias, Carlota; Zukauskas, Andrius; Trénec, Gérard; Vigué, Jacques; Chevy, Frédéric; Salomon, Christophe
2011-01-01
We present an all solid-state narrow line-width laser source emitting $670\\,\\mathrm{mW}$ output power at $671\\,\\mathrm{nm}$ delivered in a diffraction-limited beam. The source is based on a frequency-doubled diode-end-pumped ring laser operating on the ${^4F}_{3/2} \\rightarrow {^4I}_{13/2}$ transition in Nd:YVO$_4$. By using periodically-poled potassium titanyl phosphate (ppKTP) in an external build-up cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over $100\\,\\rm GHz$ is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally a simplified design based on intra-cavity doubling is described and first results are presented.
Measurements of atomic state distribution functions of the Philips QL-lamp
Energy Technology Data Exchange (ETDEWEB)
Jonkers, J.; Bakker, M.; Mullen, J.A.M. van der [Eindhoven Univ. of Technology (Netherlands). Dept. of Applied Physics
1996-12-31
In 1992 Philips Lighting introduced the QL-lamp, an inductively coupled low pressure RF discharge containing a mixture of argon and mercury. Its main advantage is the absence of electrodes, which benefits the life-time. In order to improve the knowledge of this kind of plasmas a model has been developed and measurements have been performed. In every plasma the free electrons are an important species: they control the energy transfer from the electromagnetic field to the heavy particles. Therefore, it is important to know the spatial distribution of the electron temperature and of the electron density. These parameters can be obtained from the Atomic State Distribution Function (ASDF), since the levels close the ionization limit are in partial Local Saha Equilibrium (pLSE). The densities of the excited states are obtained from absolute line intensity measurements. However, it appears that the highly excited, measurable, states are not in pLSE, indicating that the QL plasma is far from Saha equilibrium. In order to obtain the electron densities and temperatures the ASDF has to be combined with either measurements of continuum radiation or a Collisional Radiative Model (CRM). The results of both methods will be presented and compared with a third technique to obtain the electron density and temperature: Thomson scattering.
Shan, Wu-Jiang; Xia, Yan; Chen, Ye-Hong; Song, Jie
2016-06-01
By jointly using quantum Zeno dynamics and the approach of "transitionless quantum driving (TQD)" proposed by Berry to construct shortcuts to adiabatic passage, we propose an efficient scheme to fast generate multiatom Greenberger-Horne-Zeilinger (GHZ) state in separate cavities connected by optical fibers only by one-step manipulation. We first detail the generation of the three-atom GHZ state via TQD; then, we compare the proposed TQD scheme with the traditional ones with adiabatic passage. At last, the influence of various decoherence factors, such as spontaneous emission, cavity decay and fiber photon leakage, is discussed by numerical simulations. All of the results show that the present TQD scheme is fast and insensitive to atomic spontaneous emission and fiber photon leakage. Furthermore, the scheme can be directly generalized to realize N-atom GHZ state generation by the same principle in theory.
Decaying Dark Atom Constituents and Cosmic Positron Excess
DEFF Research Database (Denmark)
Belotsky, K.; Khlopov, M.; Kouvaris, C.
2014-01-01
of dark matter is in the form of a bound state between a helium nucleus and a -2 particle and a small component is in the form of a WIMP-like dark atom compatible with direct searches in underground detectors. One of the constituents of this WIMP-like state is a +2 metastable particle with a mass of 1 Te...
Effect of dipole-dipole interaction in two atom systems : A steady state analysis
Ahmed, Shaik; Lakshmi, P Anantha
2012-01-01
The behaviour of a system of two two-level atoms, both identical as well as non-identical, under the influence of a continuously varying dipole-dipole coupling parameter for a wide range of other parameters such as the atomic level separations and the coupling strength of the external radiation field is explored. A detailed analysis of the behaviour of various level populations and some of the atomic coherences is presented. The influence of the competing effects between the Rabi field strength and the dipole dipole interaction on the two photon absorption probability is explored in detail both for identical as well as non-identical atoms. There are significant variations in the behaviour of identical and non-identical atoms as a function of the dipole coupling strength, even for small amounts of non-identity of the atoms, which in this study is incorporated through the atomic level separations.
Zhao, Bin; Sun, Zhigang; Guo, Hua
2014-06-21
A recently proposed transition-state wave packet method [R. Welsch, F. Huarte-Larrañaga, and U. Manthe, J. Chem. Phys. 136, 064117 (2012)] provides an efficient and intuitive framework to study reactive quantum scattering at the state-to-state level. It propagates a few transition-state wave packets, defined by the eigenfunctions of the low-rank thermal flux operator located near the transition state, into the asymptotic regions of the reactant and product arrangement channels separately using the corresponding Jacobi coordinates. The entire S-matrix can then be assembled from the corresponding flux-flux cross-correlation functions for all arrangement channels. Since the transition-state wave packets can be defined in a relatively small region, its transformation into either the reactant or product Jacobi coordinates is accurate and efficient. Furthermore, the grid/basis for the propagation, including the maximum helicity quantum number K, is much smaller than that required in conventional wave packet treatments of state-to-state reactive scattering. This approach is implemented for atom-diatom reactions using a time-dependent wave packet method and applied to the H + D2 reaction with all partial waves. Excellent agreement with benchmark integral and differential cross sections is achieved.
Search for Long-Lived States of $\\pi^+\\pi^-$ Atoms Addendum to the DIRAC Proposal
Adeva, B; Amsler, C; Anania, A; Aogaki, S; Augsten, K; Benelli, A; Brekhovskikh, V; Cechak, T; Chiba, M; Ciortea, C; Ciocarlan, C; Constantinescu, S; Curceanu, C; Doskarova, P; Dudarev, A; Dumitriu, D; Drijard, D; Enulescu, A; Fluerasu, D; Gortchakov, O; Gritsay, K; Guaraldo, C; Gugiu, M; Hansroul, M; Hosek, R; Hons, Z; Karpukhin, V; Kluson, J; Kobayashi, M; Kulikov, A; Kulish, E; Kuptsov, A; Kruglov, V; Kruglova, L; Kuroda, K; Lamberto, A; Lednicky, R; Martincik, J; Nemenov, L; Nikitin, M; Okada, K; Pentia, M; Plo, M; Prusa, P; Rappazzo, G; Ryazantsev, A; Romero, A; Ronzhin, V; Rykalin, V; Saborido, J; Schacher, J; Shlyapnikov, P; Smolik, J; Takeutchi, F; Tarasov, A; Trojek, T; Urban, T; Vrba, T; Vazquez, P; Yazkov, V; Yoshimura, Y; Zhabitsky, M; Zrelov, P
2011-01-01
The proposed experiment is a further development of the DIRAC experiment already running at CERN PS. Up to now more than 21000 $\\pi^+\\pi^-$ pairs originated from the $\\pi^+\\pi^-$ atom ($A_{2\\pi}$) breakup were identified and the overall accuracy of the $A_{2\\pi}$ lifetime is about 9% in accordance with the DIRAC proposal. This measurement allowed to extract the difference $|a_0-a_2|$ of $s$-wave $\\pi\\pi$-scattering length with accuracy of 4.3%. The observation of long-lived (metastable) $A_{2\\pi}$ states will be performed with the same setup. This observation opens a possibility to measure the energy difference between $ns$ and $np$ states and to determine the value of another combination $2a_0+a_2$ of $\\pi\\pi$ scattering length in a model-independent way. In combination with the first measurement it allows to get $a_0$ and $a_2$ separately. An additional measurement of the multiple scattering angles in different materials with accuracy better than 1% will be performed in parallel with the observation. This m...
Bounding approaches to system identification
Norton, John; Piet-Lahanier, Hélène; Walter, Éric
1996-01-01
In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.
Schmiedmayer, Jörg; Scrinzi, Armin
1996-06-01
A neutral atom with a magnetic moment can be bound to, and guided along, a current-carrying wire. The atom is attracted to regions of high field strength (high-field seeking state) and repelled from the wire by the centrifugal barrier. In the classical regime the atoms move in Kepler-like orbits. In the quantum regime, the system resembles a two-dimensional hydrogen atom in Rydberg-like states. The wire replaces the nucleus and the atom plays the role of the electron. We give a quantum mechanical and a classical description of the system. We rigorously prove the existence of infinitely many bound states for zero or finite wire cross section and any spin (F) of the atom. The bound-state energies closely follow a Coulomb-like behaviour with an effective angular momentum, 1355-5111/8/3/029/img5.
Liang, Qiangbing; Yang, Baodong; Zhang, Tiancai; Wang, Junmin
2010-06-21
By monitoring the transmission of probe laser beam (also served as coupling laser beam) which is locked to a cycling hyperfine transition of cesium D(2) line, while pumping laser is scanned across cesium D(1) or D(2) lines, the single-resonance optical pumping (SROP) spectra are obtained with atomic vapor cell. The SROP spectra indicate the variation of the zero-velocity atoms population of one hyperfine fold of ground state, which is optically pumped into another hyperfine fold of ground state by pumping laser. With the virtue of Doppler-free linewidth, high signal-to-noise ratio (SNR), flat background and elimination of crossover resonance lines (CRLs), the SROP spectra with atomic vapor cell around room temperature can be employed to measure dressed-state splitting of ground state, which is normally detected with laser-cooled atomic sample only, even if the dressed-state splitting is much smaller than the Doppler-broaden linewidth at room temperature.
Directory of Open Access Journals (Sweden)
Yoshiki Tanaka
2015-11-01
Full Text Available The bacterial SecYEG translocon functions as a conserved protein-conducting channel. Conformational transitions of SecYEG allow protein translocation across the membrane without perturbation of membrane permeability. Here, we report the crystal structures of intact SecYEG at 2.7-Å resolution and of peptide-bound SecYEG at 3.6-Å resolution. The higher-resolution structure revealed that the cytoplasmic loop of SecG covers the hourglass-shaped channel, which was confirmed to also occur in the membrane by disulfide bond formation analysis and molecular dynamics simulation. The cytoplasmic loop may be involved in protein translocation. In addition, the previously unknown peptide-bound crystal structure of SecYEG implies that interactions between the cytoplasmic side of SecY and signal peptides are related to lateral gate opening at the first step of protein translocation. These SecYEG structures therefore provide a number of structural insights into the Sec machinery for further study.
Structure of the weakly bound triatomic He2Li and He2Na molecules
Suno, Hiroya
2017-07-01
We study the structure of triatomic molecules containing two helium atoms and one alkali-metal atom X (X = Li, Na). The three-body Schrödinger equation is solved in hyperspherical coordinates using the He-He and He-X pair van der Waals potentials available in the literature. We calculate the structural properties of the He2Li and He2Na bound states, and analyze one-dimensional pair and angle distribution functions as well as two-dimensional pair-pair and angle-angle distribution functions. These bound states are characterized by so peculiar weakly bound structures that classifying them into particular sizes and geometrical shapes appears to be elusive. Particularly, the JΠ=0+ excited states of He426Li and He427Li are found to constitute giant triatomic molecules with their size amounting to several hundred bohrs.
McAndrew, Josephine; Paul, Stephan; Emmerich, Ralf; Engels, Ralf; Fierlinger, Peter; Gabriel, Mirko; Gutsmiedl, Erwin; Mellenthin, Johannes; Schön, Johannes; Schott, Wolfgang; Ulrich, Andreas; Grüenauer, Florian; Röhrmoser, Anton
2012-05-01
An experiment to observe the bound beta-decay (BOB) of the free neutron into a hydrogen atom and an electron anti-neutrino is described. The hyperfine spin state population of the monoenergetic hydrogen atom yields the neutrino left-handedness or possible right-handed admixture as well as possible small scalar and tensor contributions to the weak force. The BOB H(2s) hyperfine states can be separated with a Lamb-Shift Spin Filter. These monoenergetic H(2s) atoms are ionised into H- by charge exchanging within an argon cell. These ions are then separated using an adaptation of a MAC-E Filter. A first experiment is proposed at the FRMII high thermal-neutron flux beam reactor SR6 through-going beam tube, where we will seek to observe this rare neutron decay-mode for the first time and determine the branching ratio. After successful completion, the hyperfine spin state population will be determined, possibly at the ILL high-flux beam reactor through-going beam tube H6-H7, where the thermal neutron flux is a factor of four larger.
Indian Academy of Sciences (India)
http://www.ias.ac.in/article/fulltext/reso/015/10/0905-0925. Keywords. Atomic theory; Avogadro's hypothesis; atomic weights; periodic table; valence; molecular weights; molecular formula; isomerism. Author Affiliations. S Ramasesha1. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, ...
Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C. T.; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey
2017-03-01
The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement.
Energy Technology Data Exchange (ETDEWEB)
Odagiri, Takeshi; Kumagai, Yoshiaki; Tanabe, Takehiko; Nakano, Motoyoshi; Kouchi, Noriyuki [Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Suzuki, Isao H, E-mail: joe@chem.titech.ac.j [Photon Factory, IMSS, KEK, Tsukuba, Ibaraki 305-0801 (Japan)
2009-11-01
Symmetry-resolved spectroscopy for investigating the doubly excited states of molecular hydrogen has been newly developed, where a metastable hydrogen atom dissociating in a direction parallel and perpendicular to the electric vector of the linearly polarized incident light is detected.
Energy Technology Data Exchange (ETDEWEB)
Buchleitner, A
1993-12-15
We develop a theoretical formalism which provides a powerful tool for the detailed numerical analysis of the interaction of three-dimensional hydrogen atoms with an intense radiation field. The application of this approach to the microwave ionization of Rydberg states of hydrogen provides the most realistic numerical experiments ever made in this area. A thorough analysis of ionization signals and thresholds, of level dynamics and of the phase space projections of associated wave functions is provided for a one-dimensional model of the atom. The comparison to the ionization of three-dimensional atoms confirms the validity of the one-dimensional model for extended initial states and, hence, dynamical localization theory, as far as the ionization threshold is concerned. Three classes of three-dimensional initial states with distinct symmetries are identified and they appear to be more or less adapted to the symmetries of the eigenstates of the microwave problem. 'Scarred' wavefunctions of the three-dimensional hydrogen atom exposed to microwave field are shown. Finally, the dynamics of a circular state in a microwave and in an intense laser field are compared. (author)
Directory of Open Access Journals (Sweden)
Suparmi
2014-12-01
Full Text Available The bound state solution of the Dirac equation for generalized PöschlTeller and trigonometric Pöschl-Teller non-central potentials was obtained using SUSY quantum mechanics and the idea of shape invariance potential. The approximate relativistic energy spectrum was expressed in the closed form. The radial and polar wave functions were obtained using raising and lowering of radial and polar operators. The orbital quantum numbers were found from the polar Dirac equation, which was solved using SUSY quantum mechanics and the idea of shape invariance.
A search for the K−pp bound state in the 3He(K−in-flight, n reaction at J-PARC
Directory of Open Access Journals (Sweden)
Hashimoto T.
2014-03-01
Full Text Available We have collected the first physics data of an experimental search for the simplest kaonic nuclear bound state, “K− pp”, by the 3He(K− n reaction at J-PARC. We confirmed that our spectrometer system works as designed and observed clear peak structure composed of the quasi-elastic K−“n” → K−n and the charge-exchange K−“p” → ¯̅K0n reactions in the forward neutron spectrum.
Charge-state distribution of Li ions from the β decay of laser-trapped 6He atoms
Hong, R.; Leredde, A.; Bagdasarova, Y.; Fléchard, X.; García, A.; Knecht, A.; Müller, P.; Naviliat-Cuncic, O.; Pedersen, J.; Smith, E.; Sternberg, M.; Storm, D. Â. W.; Swanson, H. Â. E.; Wauters, F.; Zumwalt, D.
2017-11-01
The accurate determination of atomic final states following nuclear β decay plays an important role in several experiments. In particular, the charge state distributions of ions following nuclear β decay are important for determinations of the β -ν angular correlation with improved precision. Beyond the hydrogenic cases, the decay of neutral 6He presents the simplest case. Our measurement aims at providing benchmarks to test theoretical calculations. The kinematics of Lin + ions produced following the β decay of 6He within an electric field were measured using 6He atoms in the metastable (1 s 2 s ,S31) and (1 s 2 p ,P32) states confined by a magneto-optical trap. The electron shakeoff probabilities were deduced, including their dependence on ion energy. We find significant discrepancies on the fractions of Li ions in the different charge states with respect to a recent calculation.
Bound and continuum states of molecular anions C{sub 2}H{sup -} and C{sub 3}N{sup -}
Energy Technology Data Exchange (ETDEWEB)
Harrison, Stephen; Tennyson, Jonathan, E-mail: j.tennyson@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower St, London WC1E 6BT (United Kingdom)
2011-02-28
Recently a number of molecular anions, closed-shell linear carbon chains of the form C{sub n}H{sup -} and C{sub n}N{sup -}, have been detected in space. The molecules C{sub 2}H{sup -} and C{sub 3}N{sup -} are investigated by using the R-matrix method to consider electron scattering from the corresponding neutral targets. Initial target calculations are conducted and refined in order to produce target state characteristics similar to the experimental data. A number of different scattering models are tested including static exchange and close-coupling models, and the use of Hartree-Fock or natural orbitals in the close-coupling calculations. The calculations concentrate on bound and resonances states for the anions as well as eigenphase sums, elastic cross-sections and electronic excitation cross-sections for electron collisions with the neutral. It is found that electronic resonances are all too high in energy to be important for anion formation in the interstellar medium. However, C{sub 3}N{sup -}, unlike C{sub 2}H{sup -}, supports a number of very weakly bound excited states, which may well provide the route to electron attachment for this system.
Energy Technology Data Exchange (ETDEWEB)
Li, Jingcheng; Wang, Yu [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Li, Bin, E-mail: libin@mail.ustc.edu.cn, E-mail: bwang@ustc.edu.cn; Zhao, Aidi; Wang, Bing, E-mail: libin@mail.ustc.edu.cn, E-mail: bwang@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
2015-07-21
We investigate the modification of electronic properties of single cobalt phthalocyanine (CoPc) molecule by an extra Co atom co-adsorbed on Au (111) surface using scanning tunneling microscopy (STM), joint with density functional theory (DFT) calculations. By manipulating CoPc molecules using the STM tip to contact individually adsorbed Co atom, two types of relatively stable complexes can be formed, denoted as CoPc-Co(I) and CoPc-Co(II). In CoPc-Co(I), the Co atom is at an intramolecular site close to aza-N atom of CoPc, which induces significant modifications of the electronic states of CoPc, such as energy shifts and splitting of nonlocal molecular orbitals. However, in CoPc-Co(II) where the Co atom is underneath a benzene lobe of CoPc, it only slightly modifies the electronic states of CoPc, and mainly local characteristics of specific molecular orbitals are affected, even though CoPc-Co(II) is more stable than CoPc-Co(I). Our DFT calculations give consistent results with the experiments, and related analyses based on the molecular orbital theory reveal mechanism behind the experimental observations.
Immune function in aging atomic bomb survivors residing in the United States
Energy Technology Data Exchange (ETDEWEB)
Bloom, E.T. (VA West Los Angeles Medical Center, Los Angeles, CA); Korn, E.L.; Takasugi, M.; Toji, D.S.; Onari, K.; Makinodan, T.
1983-11-01
Immunologic parameters were studied among survivors of the 1945 atomic bombs who now reside in the United States. Of all known survivors living in the US, about 40% (n = 189) participated in this study. Of those survivors on whom radiation exposure information was available (n = 168), 96% were exposed to less than 50 rad at the time of the bomb (ATB). Survivors were divided into two groups; those exposed to varying low doses of radiation (S/sub +/ group, exposed at less than or equal to 2500 m from the hypocenter) were compared with those exposed to 0 rad (S/sub 0/ group, exposed at > 2500 m from the hypocenter). Of the former group, 92% were exposed to less than 100 rad and 89% to less than 50 rad ATB. Cellular immune responses, including natural cell-mediated cytotoxicity (NCMC), interferon production, and the mitogenic response to PHA, tended to be higher among S/sub +/ individuals, although only the different for NCMC was statistically significant. This was suggestive of a trend which was consistent with the higher serum interferon levels and lower frequencies of detectable immune complexes and antimitochondrial antibodies among the S/sub +/ group, although these differences were not statistically significant.
On The Vibrational Flux in Bounded Atoms
Caturello, Naidel A M dos S
2011-01-01
In this paper we derived a model based on general assumptions and allowed us to derive some important thermodynamic functions that are time-dependent, also we could see the behavior of these functions by surfaces. The model is based on independent movements that couple and construct a flux, which makes the system as a whole not to be independent at all.
DEFF Research Database (Denmark)
Loft, N. J. S.; Marchukov, O. V.; Petrosyan, D.
2016-01-01
We have developed an efficient computational method to treat long, one-dimensional systems of strongly-interacting atoms forming self-assembled spin chains. Such systems can be used to realize many spin chain model Hamiltonians tunable by the external confining potential. As a concrete demonstrat...... demonstration, we consider quantum state transfer in a Heisenberg spin chain and we show how to determine the confining potential in order to obtain nearly-perfect state transfer....
Long-range interactions of hydrogen atoms in excited states. III. n S -1 S interactions for n ≥3
Adhikari, C. M.; Debierre, V.; Jentschura, U. D.
2017-09-01
The long-range interaction of excited neutral atoms has a number of interesting and surprising properties such as the prevalence of long-range oscillatory tails and the emergence of numerically large van der Waals C6 coefficients. Furthermore, the energetically quasidegenerate n P states require special attention and lead to mathematical subtleties. Here we analyze the interaction of excited hydrogen atoms in n S states (3 ≤n ≤12 ) with ground-state hydrogen atoms and find that the C6 coefficients roughly grow with the fourth power of the principal quantum number and can reach values in excess of 240 000 (in atomic units) for states with n =12 . The nonretarded van der Waals result is relevant to the distance range R ≪a0/α , where a0 is the Bohr radius and α is the fine-structure constant. The Casimir-Polder range encompasses the interatomic distance range a0/α ≪R ≪ℏ c /L , where L is the Lamb shift energy. In this range, the contribution of quasidegenerate excited n P states remains nonretarded and competes with the 1 /R2 and 1 /R4 tails of the pole terms, which are generated by lower-lying m P states with 2 ≤m ≤n -1 , due to virtual resonant emission. The dominant pole terms are also analyzed in the Lamb shift range R ≫ℏ c /L . The familiar 1 /R7 asymptotics from the usual Casimir-Polder theory is found to be completely irrelevant for the analysis of excited-state interactions. The calculations are carried out to high precision using computer algebra in order to handle a large number of terms in intermediate steps of the calculation for highly excited states.
Nonatomic dual bakery algorithm with bounded tokens
Aravind, Alex A.; Hesselink, Wim H.
A simple mutual exclusion algorithm is presented that only uses nonatomic shared variables of bounded size, and that satisfies bounded overtaking. When the shared variables behave atomically, it has the first-come-first-served property (FCFS). Nonatomic access makes information vulnerable. The
Energy Technology Data Exchange (ETDEWEB)
Luque, A., E-mail: a.luque@upm.es [Instituto de Energía Solar, Universidad Politécnica de Madrid (Spain); Mellor, A.; Tobías, I.; Antolín, E.; Linares, P.G.; Ramiro, I.; Martí, A. [Instituto de Energía Solar, Universidad Politécnica de Madrid (Spain)
2013-03-15
The effective mass Schrödinger equation of a QD of parallelepipedic shape with a square potential well is solved by diagonalizing the exact Hamiltonian matrix developed in a basis of separation-of-variables wavefunctions. The expected below bandgap bound states are found not to differ very much from the former approximate calculations. In addition, the presence of bound states within the conduction band is confirmed. Furthermore, filamentary states bounded in two dimensions and extended in one dimension and layered states with only one dimension bounded, all within the conduction band—which are similar to those originated in quantum wires and quantum wells—coexist with the ordinary continuum spectrum of plane waves. All these subtleties are absent in spherically shaped quantum dots, often used for modeling.
Energy Technology Data Exchange (ETDEWEB)
Silva Carvalho, Hendly da
1991-08-01
We study relativistic equations for bound states of two-body systems using Dirac`s constraint formalism and supersymmetry. The two-body system can be of spinless particles, one of them spinning and the other one spinless, or both of them spinning. The interaction is described by scalar, timelike four-vector and spacelike four-vector potentials under Lorentz transformations. As an application we use the relativistic wave equation for two scalar particles and calculate the mass spectra of the mesons treating them as spinless quark-antiquark bound states. The interaction potential in this case is a convenient adaptation of the potential employed in non-relativistic calculations. Finally, we compare our results with more recent experimental data and with theoretical results obtained with the same potential used by us but with a non-relativistic wave equation. We also compare our results with results obtained with the relativistic wave equation but with a different interaction potential. (author). 38 refs, 9 figs, 8 tabs.
Antchev, G.; The TOTEM collaboration; Atanassov, I.; Avati, V.; Baechler, J.; Barrera, C. B.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Bruce, R.; Burkhardt, H.; Cafagna, F.S.; Catanesi, M.G.; Csanad, M.; Csorgo, T.; Deile, M.; De Leonardis, F.; D'Orazio, A.; Doubek, M.; Druzhkin, D.; Eggert, K.; Eremin, V.; Ferro, F.; Fiergolski, A.; Garcia, F.; Garcia Morales, H.; Georgiev, V.; Giani, S.; Grzanka, L.; Hammerbauer, J.; Heino, J.; Helander, P.; Isidori, T.;; Ivanchenko, V.; Karev, A.; Kavspar, J.; Kopal, J.; Kosinski, J.; Kundrat, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Linhart, R.; Lindsey, C.;; Lokajivcek, M.V.; Losurdo, L; Lo Vetere, M.; Lucas-Rodriguez, F.; Lucsanyi, D.; Macri, M.; Malwski, M.; Minafra, N.; Minutoli, S.; Naaranoja, T.; Nemes, F.; Niewiadomski, H.; Novak, T.; Oliveri, E.; Oljemark, F.; Oriunno, M.; Osterberg, K.; Palazzi, P.; Palocko, L.; Passaro, V.; Peroutka, Z.; Prochazka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Redaelli, S.; Robutti, E.; Royon, C.; Ruggiero, G.; Saarikko, H.; Scribano, A.; Siroky, J.; Smajek, J.; Snoeys, W.; Stefanovitch, R.; Sziklai, J.; Taylor, C.; Tcherniaev, E.;; Turini, N.; Vacek, V.; Valentino, G.; Wenninger, J.; Welti, J.; Williams, J.; Wyszkowski, P.; Zich, J.; Zielinski, K
2017-01-01
The TOTEM experiment at the LHC has performed the first measurement at √s = 13 TeV of the ρ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at t = 0, obtaining the following results: ρ = 0.09 ± 0.01 and ρ = 0.10 ± 0.01, depending on different physics assumptions and mathematical modelling. The unprecedented precision of the ρ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than 10TeV (from 2.76 to 13TeV), has implied the exclusion of all the models classified and published by COMPETE. The ρ results obtained by TOTEM are compatible with the predictions, from alternative theoretical models both in the Regge-like framework and in the modern QCD framework, of a colourless 3-gluon bound state exchange in the t-channel of the proton-proton elastic scattering. On the contrary, if shown that the 3-gluon bound state t-channel exchange is not of importance for the description of elastic scattering, the ρ value determined by TOT...
Stanke, Monika; Adamowicz, Ludwik; Kedziera, Dariusz
2013-07-01
The inclusion of the leading quantum electrodynamic energy correction is unavoidable if one aims for sub 0.01 cm-1 accuracy in the calculations of atomic and molecular spectra. The important part of the calculation of the correction is the determination of the value of the so-called Bethe logarithm (ln k 0). In this work, we examine how to construct Gaussian basis sets for such calculations. While the testing is performed for the ground state of the hydrogen atom, the results allow us to suggest how the construction of appropriate basis sets can be handled in ln k 0 calculations of atoms and molecules with more than one electron performed with explicitly correlated all-electron Gaussian functions.
Energy Technology Data Exchange (ETDEWEB)
Celotta, R.J.; Kelley, M.H.
1988-11-15
This report discusses progress made during the current contract period on the authors research program to study collisions between spin-polarized electrons and optically prepared atoms. The objective of this work is to stimulate a deeper theoretical understanding of the electron-atom interaction by providing more complete experimental measurements on colliding systems. By preparing the internal states of the collision partners before scattering, they are able to extract substantially more information about the scattering process than is available from more conventional measurements of differential cross sections. The authors are principally interested in observing the role played by spin in low energy electron-atom collisions. The additional information provided by these spin-dependent measurements can greatly enhance understanding of both exchange and the spin-orbit interaction in the scattering process. They have made substantial progress in the past three years in their measurements both of elastic and superelastic scattering of spin-polarized electrons from optically pumped sodium.
Energy Technology Data Exchange (ETDEWEB)
Kupliauskiene, A [Institute of Theoretical Physics and Astronomy of Vilnius University, A Gostauto 12, 2600 Vilnius (Lithuania); Glemza, K [Vilnius University, Sauletekio 9, Vilnius (Lithuania)
2002-11-28
The probability of the shaking process accompanying inner-shell ionization (expressed as the square of the overlap integrals of valence electron radial orbitals in the initial and final states) is calculated for a number of second- and third-row atoms and singly and doubly charged ions (in the excited states of n{sub 0} l{sub 0}{sup N} nl (3{<=}n{<=}9, 0{<=}l{<=}3)). Enormous differences are found for the low-excited n s and n p states between shake probabilities that are calculated using numerical solutions of Hartree-Fock equations and hydrogenic radial orbitals (with an effective nuclear charge and with an effective principal quantum number obtained from experimental binding energies). The results can be a useful guide in the search for strong relaxation effects in the Auger decay and inner-shell ionization of excited atoms and ions by photons and electrons as well as in sudden-perturbation approximation calculations.