Spek, Anthony L
2015-01-01
The completion of a crystal structure determination is often hampered by the presence of embedded solvent molecules or ions that are seriously disordered. Their contribution to the calculated structure factors in the least-squares refinement of a crystal structure has to be included in some way. Traditionally, an atomistic solvent disorder model is attempted. Such an approach is generally to be preferred, but it does not always lead to a satisfactory result and may even be impossible in cases where channels in the structure are filled with continuous electron density. This paper documents the SQUEEZE method as an alternative means of addressing the solvent disorder issue. It conveniently interfaces with the 2014 version of the least-squares refinement program SHELXL [Sheldrick (2015). Acta Cryst. C71. In the press] and other refinement programs that accept externally provided fixed contributions to the calculated structure factors. The PLATON SQUEEZE tool calculates the solvent contribution to the structure factors by back-Fourier transformation of the electron density found in the solvent-accessible region of a phase-optimized difference electron-density map. The actual least-squares structure refinement is delegated to, for example, SHELXL. The current versions of PLATON SQUEEZE and SHELXL now address several of the unnecessary complications with the earlier implementation of the SQUEEZE procedure that were a necessity because least-squares refinement with the now superseded SHELXL97 program did not allow for the input of fixed externally provided contributions to the structure-factor calculation. It is no longer necessary to subtract the solvent contribution temporarily from the observed intensities to be able to use SHELXL for the least-squares refinement, since that program now accepts the solvent contribution from an external file (.fab file) if the ABIN instruction is used. In addition, many twinned structures containing disordered solvents are now also
Socrates: Platonic Political Ideal
Directory of Open Access Journals (Sweden)
Christopher P. Long
2012-08-01
Full Text Available This essay articulates the differences and suggests the similarities between the practices of Socratic political speaking and those of Platonic political writing. The essay delineates Socratic speaking and Platonic writing as both erotically oriented toward ideals capable of transforming the lives of individuals and their relationships with one another. Besides it shows that in the Protagoras the practices of Socratic political speaking are concerned less with Protagoras than with the individual young man, Hippocrates. In the Phaedo, this ideal of a Socrates is amplified in such a way that Platonic writing itself emerges as capable of doing with readers what Socratic speaking did with those he encountered. Socrates is the Platonic political ideal. The result is a picture of the transformative political power of Socratic speaking and Platonic writing both.
DEFF Research Database (Denmark)
Ostenfeld, Erik Nis
2011-01-01
Artiklen falder i to dele, en metodisk del og en gennemgang af hovedpunkter i Platons filosofi. Det er almindelig viden blandt oplyste, uddannede mennesker, at Platon er en af de vigtigste filosoffer overhovedet i den vesterlandske kultur. Dette illustreres af den indflydelse på filosofi......, litteratur og kultur, han har haft i de 2500 år, der er gået, siden han levede. Man mener også at vide, at Platons filosofi bl.a. indeholder forestillinger om en ideverden og en udødelig sjæl, der midlertidigt er havnet i en distraherende uvirkelig skyggeverden. Ved filosofiens hjælp kan den vende tilbage...... til skuet af ideerne. Hertil hører også billedet af den tredelte sjæl som en kusk med vognspand af to mere eller mindre uregerlige heste. Endelig er Platon forbundet med ideen om en idealstat regeret af filosoffer. Skønt alle disse forestillinger findes i Platons værk, er det ikke korrekt at antage...
DEFF Research Database (Denmark)
Ostenfeld, Erik Nis
2011-01-01
Artiklen falder i to dele, en metodisk del og en gennemgang af hovedpunkter i Platons filosofi. Det er almindelig viden blandt oplyste, uddannede mennesker, at Platon er en af de vigtigste filosoffer overhovedet i den vesterlandske kultur. Dette illustreres af den indflydelse på filosofi......, litteratur og kultur, han har haft i de 2500 år, der er gået, siden han levede. Man mener også at vide, at Platons filosofi bl.a. indeholder forestillinger om en ideverden og en udødelig sjæl, der midlertidigt er havnet i en distraherende uvirkelig skyggeverden. Ved filosofiens hjælp kan den vende tilbage...... til skuet af ideerne. Hertil hører også billedet af den tredelte sjæl som en kusk med vognspand af to mere eller mindre uregerlige heste. Endelig er Platon forbundet med ideen om en idealstat regeret af filosoffer. Skønt alle disse forestillinger findes i Platons værk, er det ikke korrekt at antage...
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2014-03-01
Full Text Available L’ipertesto dedicata al Carmide di Platone, composto per l’uso degli studenti dell’ateneo pisano, è a disposizione di tutti qui. Il Carmide è – canonicamente – un dialogo aporetico. Ma almeno dei suoi paradossi – quello di una superscienza che pretende...
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2013-01-01
Full Text Available Pensate che i testi antichi siano semplicemente vecchi? Che l’amore platonico non vada mai al sodo? Leggere il Simposio di Platone confrontandosi direttamente col testo, com’è possibile fare grazie al Perseus Project, vi farà cambiare idea.
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2015-06-01
Full Text Available La guida ipertestuale alla lettura del Cratilo di Platone composta per gli studenti della facoltà di Scienze politiche dell’università di Pisa è ora visibile a tutti qui. L’ipertesto ha tratto vantaggio dall’Introduzione alla linguistica generale del professor Manuel Barbera dell’università...
Platons ‘respekt’ for Protagoras
DEFF Research Database (Denmark)
Bloch, David
2011-01-01
Platons forhold til sofisten Protagoras behandles. Hvor forskningen oftest har hævdet, at Platon har stor respekt for denne, argumenteres der her for, at Platons dialog "Protagoras" viser alt andet end respekt.......Platons forhold til sofisten Protagoras behandles. Hvor forskningen oftest har hævdet, at Platon har stor respekt for denne, argumenteres der her for, at Platons dialog "Protagoras" viser alt andet end respekt....
Aleman, Monica; Weich, Kalie M; Madigan, John E
2017-09-05
Horses are a precocious species that must accomplish several milestones that are critical to survival in the immediate post-birth period for their survival. One essential milestone is the successful transition from the intrauterine unconsciousness to an extrauterine state of consciousness or awareness. This transition involves a complex withdrawal of consciousness inhibitors and an increase in neuroactivating factors that support awareness. This process involves neuroactive hormones as well as inputs related to factors such as cold, visual, olfactory, and auditory stimuli. One factor not previously considered in this birth transition is a yet unreported direct neural reflex response to labor-induced physical compression of the fetus in the birth canal (squeezing). Neonatal maladjustment syndrome (NMS) is a disorder of the newborn foal characterized by altered behavior, low affinity for the mare, poor awareness of the environment, failure to bond to the mother, abnormal sucking, and other neurologically-based abnormalities. This syndrome has been associated with altered events during birth, and was believed to be caused exclusively by hypoxia and ischemia. However, recent findings revealed an association of the NMS syndrome with the persistence of high concentrations of in utero neuromodulating hormones (neurosteroids) in the postnatal period. Anecdotal evidence demonstrated that a novel physical compression (squeeze) method that applies 20 min of sustained pressure to the thorax of some neonatal foals with this syndrome might rapidly hasten recovery. This survey provides information about outcomes and time frames to recovery comparing neonatal foals that were given this squeeze treatment to foals treated with routine medical therapy alone. Results revealed that the squeeze procedure, when applied for 20 min, resulted in a faster full recovery of some foals diagnosed with NMS. The adjunctive use of a non-invasive squeeze method may improve animal welfare by
Platonism, Naturalism, and Mathematical Knowledge
Brown, James Robert
2011-01-01
This study addresses a central theme in current philosophy: Platonism vs Naturalism and provides accounts of both approaches to mathematics, crucially discussing Quine, Maddy, Kitcher, Lakoff, Colyvan, and many others. Beginning with accounts of both approaches, Brown defends Platonism by arguing that only a Platonistic approach can account for concept acquisition in a number of special cases in the sciences. He also argues for a particular view of applied mathematics, a view that supports Platonism against Naturalist alternatives. Not only does this engaging book present the Platonist-Natural
Yong, Ee Hou; Nelson, David R; Mahadevan, L
2013-10-25
On microscopic scales, the crystallinity of flexible tethered or cross-linked membranes determines their mechanical response. We show that by controlling the type, number, and distribution of defects on a spherical elastic shell, it is possible to direct the morphology of these structures. Our numerical simulations show that by deflating a crystalline shell with defects, we can create elastic shell analogs of the classical platonic solids. These morphologies arise via a sharp buckling transition from the sphere which is strongly hysteretic in loading or unloading. We construct a minimal Landau theory for the transition using quadratic and cubic invariants of the spherical harmonic modes. Our approach suggests methods to engineer shape into soft spherical shells using a frozen defect topology.
Manton, Nicholas
2014-01-01
We construct a number of explicit examples of hyperbolic monopoles, with various charges and often with some platonic symmetry. The fields are obtained from instanton data in four-dimensional Euclidean space that are invariant under a circle action, and the monopole charge is equal to the instanton charge. A key ingredient is the identification of a new set of constraints on ADHM instanton data that are sufficient to ensure the circle invariance. Algebraic formulae for the Higgs field magnitude are given and from these we compute and illustrate the energy density of the monopoles. For particular monopoles, the explicit formulae provide a proof that the number of zeros of the Higgs field is greater than the monopole charge. We also present some one-parameter families of monopoles analogous to known scattering events for Euclidean monopoles within the geodesic approximation.
Origen and the Platonic Tradition
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Ilaria L.E. Ramelli
2017-02-01
Full Text Available This study situates Origen of Alexandria within the Platonic tradition, presenting Origenas a Christian philosopher who taught and studied philosophy, of which theology was part and parcel. More speciﬁcally, Origen can be described as a Christian Platonist. He criticized “false philosophies” as well as “heresies,” but not the philosophy of Plato. Against the background of recent scholarly debates, the thorny issue of the possible identity between Origen the Christian Platonist and Origen the Neoplatonist is partially addressed (although it requires a much more extensive discussion; it is also discussed in the light of Origen’s formation at Ammonius’s school and the reception of his works and ideas in “pagan” Platonism. As a consequence, and against scholarly perspectives that tend to see Christianity as anti-Platonism, the ﬁnal section of this paper asks the question of what is imperial and late antique Platonism and, on the basis of rich evidence ,suggests that this was not only “pagan” institutional Platonism.
Godel's Incompleteness Theorems and Platonic Metaphysics
Mikovic, Aleksandar
2015-01-01
We argue by using Godel's incompletness theorems in logic that platonism is the best metaphysics for science. This is based on the fact that a natural law in a platonic metaphysics represents a timeless order in the motion of matter, while a natural law in a materialistic metaphysics can be only defined as a temporary order which appears at random in the chaotic motion of matter. Although a logical possibility, one can argue that this type of metaphysics is highly implausible. Given that mathematics fits naturally within platonism, we conclude that a platonic metaphysics is more preferable than a materialistic metaphysics.
Platonism in Preface to Lyrical Ballads
Institute of Scientific and Technical Information of China (English)
严文烨
2016-01-01
Platonism has exerted great influence on Romanticism. Wordsworth, as the leading figure of English Romanticism, was inevitably influenced by Plato. Preface to Lyrical Ballads is Wordsworth's declaration of Romanticism. In this essay, the inheritance and innovation of Platonism in Preface to Lyrical Ballads is analyzed from three aspects: mimetic theories, pragmatism and expressive theories.
Platonic wholes and quantum ontology
Woszczek, Marek
2015-01-01
The subject of the book is a reconsideration of the internalistic model of composition of the Platonic type, more radical than traditional, post-Aristotelian externalistic compositionism, and its application in the field of the ontology of quantum theory. At the centre of quantum ontology is nonseparability. Quantum wholes are atemporal wholes governed by internalistic logic and they are primitive, global physical entities, requiring an extreme relativization of the fundamental notions of mechanics. That ensures quantum theory to be fully consistent with the relativistic causal structure, with
Faces of platonic solids in all dimensions
Szajewska, Marzena
2012-01-01
This paper considers Platonic solids/polytopes in the real Euclidean space R^n of dimension 3 <= n < infinity. The Platonic solids/polytopes are described together with their faces of dimensions 0 <= d <= n-1. Dual pairs of Platonic polytopes are considered in parallel. The underlying fi?nite Coxeter groups are those of simple Lie algebras of types An, Bn, Cn, F4 and of non-crystallographic Coxeter groups H3, H4. Our method consists in recursively decorating the appropriate Coxeter-Dynkin diagram. Each recursion step provides the essential information about faces of a speci?c dimension. If, at each recursion step, all of the faces are in the same Coxeter group orbit, i.e. are identical, the solid is called Platonic.
Quantum Averaging of Squeezed States of Light
DEFF Research Database (Denmark)
Squeezing has been recognized as the main resource for quantum information processing and an important resource for beating classical detection strategies. It is therefore of high importance to reliably generate stable squeezing over longer periods of time. The averaging procedure for a single qu...
DEFF Research Database (Denmark)
Olsen, Anne-Marie Eggert
2015-01-01
Artiklen præsenterer i første del (A) det pædagogiske stof fra Platons Staten og Lovene, som Rousseau har læst og fundet inspiration i. Der plæderes for, at Rousseau optager og transponerer såvel principper som konkrete overvejelser uanset den forskelige historiske kontekst og de dermed sammenhæn......Artiklen præsenterer i første del (A) det pædagogiske stof fra Platons Staten og Lovene, som Rousseau har læst og fundet inspiration i. Der plæderes for, at Rousseau optager og transponerer såvel principper som konkrete overvejelser uanset den forskelige historiske kontekst og de dermed...... sammenhængende forskellige udformninger og mål for opdragelsen. I anden del (B) diskuteres Rousseaus ’platonisme’ i mere overordnet filosofisk sammenhæng, og der argumenteres for, at Rousseaus utraditionelle, pædagogisk-filosofiske Platon-læsning dels kan ses at fremdrage underbelyste centrale tematikker i...... Platons filosofi, dels understreger deres stadige aktualitet....
Plato's problem an introduction to mathematical platonism
Panza, M
2013-01-01
What is mathematics about? And how can we have access to the reality it is supposed to describe? The book tells the story of this problem, first raised by Plato, through the views of Aristotle, Proclus, Kant, Frege, Gödel, Benacerraf, up to the most recent debate on mathematical platonism.
Flexural Mie Resonances: Localized Surface Platonic Modes
Farhat, M; Chen, P Y; Salama, K N; Bagci, H
2016-01-01
Surface plasmons polaritons were thought to exist only in metals near their plasma frequencies. The concept of spoof plasmons extended the realms of plasmonics to domains such as radio frequencies, magnetism, or even acoustic waves. Here, we introduce the concept of localized surface platonic modes (SPMs). We demonstrate that they can be generated on a two-dimensional clamped (or stress-free) cylindrical surface, in a thin elastic plate, with subwavelength corrugations under excitation by an incident flexural plane wave. Our results show that the corrugated rigid surface is elastically equivalent to a cylindrical scatterer with negatively uniform and dispersive flexural rigidity. This, indeed, suggests that plasmonic-like platonic materials can be engineered with potential applications in various areas including earthquake sensing, or elastic imaging and cloaking.
The origin of the division between Middle Platonism and Neoplatonism
DEFF Research Database (Denmark)
Catana, Leo
2013-01-01
The division of Ancient Platonism into Middle Platonism and Neoplatonism is a fairly new one. The conceptual foundation of this division was cemented in Jacob Brucker’s pioneering Historia critica philosophiae (1742-44). In the 1770s and 1780s, the term ‘Neoplatonism’ was coined on the basis...... of Brucker’s analysis. Three historiographical concepts were decisive to Brucker: ‘system of philosophy’, ‘eclecticism’ and ‘syncretism’. By means of these concepts, he characterized Middle Platonism and Neoplatonism as opposing philosophical movements, the former being a genuine form of Platonism...
Heuristics of the Platonic Polyhedra for the high Restrictions Reality Research
Directory of Open Access Journals (Sweden)
José Ricardo Díaz Caballero
2013-02-01
Full Text Available In the present work, are exposed concepts, principles and procedures that make up a theory for theheuristical geometrical interpretation of high restrictions reality, based on a thesis where the PlatonicPolyhedra are carriers of a content with a high heuristic potential for the theoretical interpretation ofreality, particularly the high restriction systems , for example the Periodic Table of Chemical Elements,the System of Notes and Tempered Musical Scales and the Universal Genetic Code.
Pulsed squeezed vacuum characterization without homodyning
Wenger, J; Tualle-Brouri, R; Cerf, N J; Grangier, P; Grangier, Ph.
2004-01-01
Direct photon detection is experimentally implemented to measure the squeezing and purity of a single-mode squeezed vacuum state without an interferometric homodyne detection. Following a recent theoretical proposal [arXiv quant-ph/0311119], the setup only requires a tunable beamsplitter and a single-photon detector to fully characterize the generated Gaussian states. The experimental implementation of this procedure is discussed and compared with other reference methods.
Squeezing Properties of the Generalized Multimode Squeezed States
Institute of Scientific and Technical Information of China (English)
SONGTong－Qiang
2001-01-01
By means of the invariance of Weyl ordering under similar transformations we derive the explicit form of the generalized multimode squeezed states.Moreover,the completeness relation and the squeezing properties of the generalized multimode squeezed states are discussed.
Squeezing Properties of the Generalized Multimode Squeezed States
Institute of Scientific and Technical Information of China (English)
SONG Tong-Qiang
2001-01-01
By means of the invariance of Weyl ordering under similar transformations we derive the explicit form of the generalized multimode squeezed states. Moreover, the completeness relation and the squeezing properties of the generalized multimode squeezed states are discussed.
BOOK REVIEW: Quantum Squeezing
Zubairy, Suhail
2005-05-01
Quantum squeezed states are a consequence of uncertainty relations; a state is squeezed when the noise in one variable is reduced below the symmetric limit at the expense of the increased noise in the conjugate variable such that the Heisenberg uncertainty relation is not violated. Such states have been known since the earliest days of quantum mechanics. The realization in the early 80's that quantum squeezed states of the radiation field can have important applications in high precision Michelson interferometry for detecting gravitational waves led to a tremendous amount of activity, both in theoretical and experimental quantum optics. The present volume, edited by two eminent scientists, is a collection of papers by leading experts in the field of squeezed states on different aspects of the field as it stands today. The book is divided into three parts. In the first part, there are three articles that review the fundamentals. The first paper by Knight and Buzek presents an introductory account of squeezed states and their properties. The chapter, which opens with the quantization of the radiation field, goes on to discuss the quantum optical properties of single mode and multimode squeezed states. The second article by Hillery provides a detailed description of field quantization in the presence of a nonlinear dielectric medium, thus providing a rigorous treatment of squeezing in nonlinear media. The third article by Yurke presents a comprehensive discussion of the input-output theory of the squeezed radiation at the dielectric boundaries. The second part of the book, comprising of three articles, deals with the generation of squeezed states. In the first article, Drummond reviews the squeezing properties of light in nonlinear systems such as parametric oscillators. He also discusses squeezed light propagation through waveguides and optical fibers. In the second article, Ralph concentrates on active laser sources of squeezing and presents an analysis based on the
Aragone, C.
1993-01-01
We introduce a new set of squeezed states through the coupled two-mode squeezed operator. It is shown that their behavior is simpler than the correlated coherent states introduced by Dodonov, Kurmyshev, and Man'ko in order to quantum mechanically describe the Landau system, i.e., a planar charged particle in a uniform magnetic field. We compare results for both sets of squeezed states.
Die Aufgabe des Gesetzes bei Solon und Platon
Marti, Urs
2011-01-01
Solon und Platon werden in der Literatur häufig in einem Zug genannt. Bereits Solon habe das Gesetz verstanden als Instrument zur Überwindung einer politischen Unordnung, die aus der mangelnden moralischen Qualifikation der Bürger resultiere. Die verbreitete Ansicht, Solon habe die politische Philosophie Platons vorweggenommen, bedarf der kritischen Prüfung. Tatsächlich versteht Platon unter Politik primär die moralische Erziehung der Bürger, während soziale Konflikte als Ursachen der Unordnu...
Architecture of Platonic and Archimedean polyhedral links
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
A new methodology for understanding the construction of polyhedral links has been developed on the basis of the Platonic and Archimedean solids by using our method of the 'three-cross-curve and doubletwist-line covering'. There are five classes of polyhedral links that can be explored: the tetrahedral and truncated tetrahedral links; the hexahedral and truncated hexahedral links; the dodecahedral and truncated dodecahedral links; the truncated octahedral and icosahedral links. Our results show that the tetrahedral and truncated tetrahedral links have T symmetry; the hexahedral and truncated hexahedral links, as well as the truncated octahedral links, O symmetry; the dodecahedral and truncated dodecahedral links, as well as the truncated icosahedral links, I symmetry, respectively. This study provides further insight into the molecular design, as well as theoretical characterization, of the DNA and protein catenanes.
Architecture of Platonic and Archimedean polyhedral links
Institute of Scientific and Technical Information of China (English)
2008-01-01
A new methodology for understanding the construction of polyhedral links has been developed on the basis of the Platonic and Archimedean solids by using our method of the ‘three-cross-curve and dou- ble-twist-line covering’. There are five classes of polyhedral links that can be explored: the tetrahedral and truncated tetrahedral links; the hexahedral and truncated hexahedral links; the dodecahedral and truncated dodecahedral links; the truncated octahedral and icosahedral links. Our results show that the tetrahedral and truncated tetrahedral links have T symmetry; the hexahedral and truncated hexahedral links, as well as the truncated octahedral links, O symmetry; the dodecahedral and truncated dodeca- hedral links, as well as the truncated icosahedral links, I symmetry, respectively. This study provides further insight into the molecular design, as well as theoretical characterization, of the DNA and protein catenanes.
Teleporting squeezing: Optimization using non-Gaussian resources
Dell'Anno, F; Adesso, G; Illuminati, F
2010-01-01
We study the continuous-variable quantum teleportation of states, statistical moments of observables, and scale parameters such as squeezing. We investigate the problem both in ideal and imperfect Vaidman-Braunstein-Kimble protocol setups. We show how the teleportation fidelity is maximized and the difference between output and input variances is minimized by using suitably optimized entangled resources. Specifically, we consider the teleportation of coherent squeezed states, exploiting squeezed Bell states as entangled resources. This class of non-Gaussian states includes photon-added and photon-subtracted squeezed states as special cases. At variance with the case of entangled Gaussian resources, the use of entangled non-Gaussian squeezed Bell resources allows for different optimization procedures that lead to inequivalent results. Performing two independent optimization procedures one can either maximize the state teleportation fidelity, or minimize the difference between input and output quadrature varian...
Platonic solids in $\\mathbb Z^3$
Ionascu, Eugen J
2009-01-01
Extending previous results on a characterization of all equilateral triangle in space having vertices with integer coordinates ("in $\\mathbb Z^3$"), we look at the problem of characterizing all regular polyhedra (Platonic Solids) with the same property. To summarize, we show first that there is no regular icosahedron/ dodecahedron in $\\mathbb Z^3$. On the other hand, there is a finite (6 or 12) class of regular tetrahedra in $\\mathbb Z^3$, associated naturally to each nontrivial solution $(a,b,c,d)$ of the Diophantine equation $a^2+b^2+c^2=3d^2$ and for every nontrivial integer solution $(m,n,k)$ of the equation $m^2-mn+n^2=k^2$. Every regular tetrahedron in $\\mathbb Z^3$ belongs, up to an integer translation and/or rotation, to one of these classes. We then show that each such tetrahedron can be completed to a cube with integer coordinates. The study of regular octahedra is reduced to the cube case via the duality between the two. This work allows one to basically give a description the orthogonal group $O(3...
Searching for integrable Hamiltonian systems with Platonic symmetries
Rastelli, Giovanni
2010-01-01
In this paper we try to find examples of integrable natural Hamiltonian systems on the sphere $S^2$ with the symmetries of each Platonic polyhedra. Although some of these systems are known, their expression is extremely complicated; we try here to find the simplest possible expressions for this kind of dynamical systems. Even in the simplest cases it is not easy to prove their integrability by direct computation of the first integrals, therefore, we make use of numerical methods to provide evidences of integrability; namely, by analyzing their Poincar\\'e sections (surface sections). In this way we find three systems with platonic symmetries, one for each class of equivalent Platonic polyhedra: tetrahedral, exahedral-octahedral, dodecahedral-icosahedral, showing evidences of integrability. The proof of integrability and the construction of the first integrals are left for further works. As an outline of the possible developments if the integrability of these systems will be proved, we show how to build from th...
Impact of Platon ETC system on intercity trucking cost
Directory of Open Access Journals (Sweden)
Pogotovkina Natalya
2017-01-01
Full Text Available In 2015 Platon ETC System, a system of charging trucks with gross vehicle weight exceeding 12 tons, was implemented in Russia. The payment is collected as a compensation fo0 the damage caused to the federal public roads. Platon system is an additional source of financing for the road sector. However, its implementation made the carriers face the increasing costs. This paper presents the first results of the system functioning and the problems, associated with it. We consider the foreign systems of truck charging. The results of calculations, which show the effect of the toll collection on the prime cost of road freight transportation, are also presented.
Piiskop Platoni protest saksa okupatsiooni vastu a. 1918 / Piiskop Platon
Platon, Eesti Apostlik-Õigeusu kiriku peapiiskop, 1869-1919
1987-01-01
Piiskop Platon (kodanikunimega Paul Kulbusch) kirjeldab saksa okupatsiooni Eestis ja Lätis, Riia õigeusu kirikute ümberehitamist luteri kirikuteks, preestrite tagakiusamist ja väljasaatmist. A. Piibule Londonisse lääneriikide esindajatele levitamiseks saadetud pöördumise tekstile eelneb Esmo Ridala sissejuhatus ülevaatega piiskop Platoni eluloost
I grandi della fisica da Platone a Heisenberg
Von Weizsäcker, Carl Friedrich
2002-01-01
Parmenide ; Platone ; Aristotele ; Copernico, Keplero, Galilei ; Galileo Galilei ; Cartesio ; Gottfried Wilhelm Leibniz ; Cartesio, Newton, Leibniz, Kant ; Immanuel Kant ; Johann Wolfgang Goethe ; Robert Meyer ; Albert Einstein ; Niels Bohr ; Paul Adrien Maurice Dirac ; Niels Bohr e Werner Heisenberg, un ricordo del 1932 ; Werner Heisenberg ; Heisenberg, fisico e filosofo ; l'interpretazione filosofica della fisica moderna.
Platonic solids generate their four-dimensional analogues
Dechant, Pierre-Philippe
2013-01-01
In this paper, we show how regular convex 4-polytopes - the analogues of the Platonic solids in four dimensions - can be constructed from three-dimensional considerations concerning the Platonic solids alone. Via the Cartan-Dieudonne theorem, the reflective symmetries of the Platonic solids generate rotations. In a Clifford algebra framework, the space of spinors generating such three-dimensional rotations has a natural four-dimensional Euclidean structure. The spinors arising from the Platonic Solids can thus in turn be interpreted as vertices in four-dimensional space, giving a simple construction of the 4D polytopes 16-cell, 24-cell, the F_4 root system and the 600-cell. In particular, these polytopes have `mysterious' symmetries, that are almost trivial when seen from the three-dimensional spinorial point of view. In fact, all these induced polytopes are also known to be root systems and thus generate rank-4 Coxeter groups, which can be shown to be a general property of the spinor construction. These cons...
Piiskop Platoni protest saksa okupatsiooni vastu a. 1918 / Piiskop Platon
Platon, Eesti Apostlik-Õigeusu kiriku peapiiskop, 1869-1919
1987-01-01
Piiskop Platon (kodanikunimega Paul Kulbusch) kirjeldab saksa okupatsiooni Eestis ja Lätis, Riia õigeusu kirikute ümberehitamist luteri kirikuteks, preestrite tagakiusamist ja väljasaatmist. A. Piibule Londonisse lääneriikide esindajatele levitamiseks saadetud pöördumise tekstile eelneb Esmo Ridala sissejuhatus ülevaatega piiskop Platoni eluloost
Labudde, D; Leitner, D; Krüger, M; Oschkinat, H
2003-01-01
The algorithm PLATON is able to assign sets of chemical shifts derived from a single residue to amino acid types with its secondary structure (amino acid species). A subsequent ranking procedure using optionally two different penalty functions yields predictions for possible amino acid species for the given set of chemical shifts. This was demonstrated in the case of the alpha-spectrin SH3 domain and applied to 9 further protein data sets taken from the BioMagRes database. A database consisting of reference chemical shift patterns (reference CSPs) was generated from assigned chemical shifts of proteins with known 3D-structure. This reference CSP database is used in our approach for extracting distributions of amino acid types with their most likely secondary structure elements (namely alpha-helix, beta-sheet, and coil) for single amino acids by comparison with query CSPs. Results obtained for the 10 investigated proteins indicates that the percentage of correct amino acid species in the first three positions in the ranking list, ranges from 71.4% to 93.2% for the more favorable penalty function. Where only the top result of the ranking list for these 10 proteins is considered, 36.5% to 83.1% of the amino acid species are correctly predicted. The main advantage of our approach, over other methods that rely on average chemical shift values is the ability to increase database content by incorporating newly derived CSPs, and therefore to improve PLATON's performance over time.
Teleportation of squeezing: Optimization using non-Gaussian resources
Dell'Anno, Fabio; de Siena, Silvio; Adesso, Gerardo; Illuminati, Fabrizio
2010-12-01
We study the continuous-variable quantum teleportation of states, statistical moments of observables, and scale parameters such as squeezing. We investigate the problem both in ideal and imperfect Vaidman-Braunstein-Kimble protocol setups. We show how the teleportation fidelity is maximized and the difference between output and input variances is minimized by using suitably optimized entangled resources. Specifically, we consider the teleportation of coherent squeezed states, exploiting squeezed Bell states as entangled resources. This class of non-Gaussian states, introduced by Illuminati and co-workers [F. Dell’Anno, S. De Siena, L. Albano, and F. Illuminati, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.76.022301 76, 022301 (2007); F. Dell’Anno, S. De Siena, and F. Illuminati, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.81.012333 81, 012333 (2010)], includes photon-added and photon-subtracted squeezed states as special cases. At variance with the case of entangled Gaussian resources, the use of entangled non-Gaussian squeezed Bell resources allows one to choose different optimization procedures that lead to inequivalent results. Performing two independent optimization procedures, one can either maximize the state teleportation fidelity, or minimize the difference between input and output quadrature variances. The two different procedures are compared depending on the degrees of displacement and squeezing of the input states and on the working conditions in ideal and nonideal setups.
Topology of Platonic Spherical Manifolds: From Homotopy to Harmonic Analysis
Kramer, Peter
2015-01-01
We carry out the harmonic analysis on four Platonic spherical three-manifolds with different topologies. Starting out from the homotopies (Everitt 2004), we convert them into deck operations, acting on the simply connected three-sphere as the cover, and obtain the corresponding variety of deck groups. For each topology, the three-sphere is tiled into copies of a fundamental domain under the corresponding deck group. We employ the point symmetry of each Platonic manifold to construct its fundamental domain as a spherical orbifold. While the three-sphere supports an~orthonormal complete basis for harmonic analysis formed by Wigner polynomials, a given spherical orbifold leads to a selection of a specific subbasis. The resulting selection rules find applications in cosmic topology, probed by the cosmic microwave background.
Spin squeezing and quantum correlations
Indian Academy of Sciences (India)
K S Mallesh; Swarnamala Sirsi; Mahmoud A A Sbaih; P N Deepak; G Ramachandran
2002-08-01
We discuss the notion of spin squeezing considering two mutually exclusive classes of spin- states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin- states using 2 spinors oriented along different axes. Taking the case of = 1, we show that the `non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.
Pulsed squeezed light: simultaneous squeezing of multiple modes
Wasilewski, W; Banaszek, K; Radzewicz, C; Wasilewski, Wojciech; Banaszek, Konrad; Radzewicz, Czeslaw
2005-01-01
We analyze the spectral properties of squeezed light produced by means of pulsed, single-pass degenerate parametric down-conversion. The multimode output of this process can be decomposed into characteristic modes undergoing independent squeezing evolution akin to the Schmidt decomposition of the biphoton spectrum. The main features of this decomposition can be understood using a simple analytical model developed in the perturbative regime. In the strong pumping regime, for which the perturbative approach is not valid, we present a numerical analysis, specializing to the case of one-dimensional propagation in a beta-barium borate waveguide. Characterization of the squeezing modes provides us with an insight necessary for optimizing homodyne detection of squeezing. For a weak parametric process, efficient squeezing is found in a broad range of local oscillator modes, whereas the intense generation regime places much more stringent conditions on the local oscillator. We point out that without meeting these cond...
Correlation measurement of squeezed light
DEFF Research Database (Denmark)
Krivitsky, Leonid; Andersen, Ulrik Lund; Dong, R.;
2009-01-01
We study the implementation of a correlation measurement technique for the characterization of squeezed light which is nearly free of electronic noise. With two different sources of squeezed light, we show that the sign of the covariance coefficient, revealed from the time-resolved correlation data...
Squeezed light in semiconductors
Ward, M B
2001-01-01
Experimental evidence is presented for the generation of photon-number squeezed states of light as a result of multi-photon absorption. Photon-number squeezing as a result of non-linear absorption has long been predicted and results have been obtained utilising two very different material systems: (i) an AIGaAs waveguide in which high optical intensities can be maintained over a relatively long interaction length of 2 mm; (ii) the organic polymer p-toluene sulphonate polydiacetylene that is essentially a one-dimensional semiconductor possessing a highly nonlinear optical susceptibility. The resulting nonlinear absorption is shown to leave the transmitted light in a state that is clearly nonclassical, exhibiting photon-number fluctuations below the shot-noise limit. Tuning the laser wavelength across the half-bandgap energy has enabled a comparison between two- and three-photon processes in the semiconductor waveguide. The correlations created between different spectral components of a pulsed beam of light as ...
Erotic Wisdom and the Socratic Vocation in Plutarch’s Platonic Question 1
Directory of Open Access Journals (Sweden)
Mark Shiffman
2010-11-01
Full Text Available Plutarch's skeptical Platonism is embodied in his understanding of Socrates and Socrates' use of eros, and serves to harmonize his use of the skeptical heritage with his understanding of central Platonic teachings: questioning is the crucial tool in the search for wisdom.
Flat Zipper-Unfolding Pairs for Platonic Solids
O'Rourke, Joseph
2010-01-01
We show that four of the five Platonic solids' surfaces may be cut open with a Hamiltonian path along edges and unfolded to a polygonal net each of which can "zipper-refold" to a flat doubly covered parallelogram, forming a rather compact representation of the surface. Thus these regular polyhedra have particular flat "zipper pairs." No such zipper pair exists for a dodecahedron, whose Hamiltonian unfoldings are "zip-rigid." This report is primarily an inventory of the possibilities, and raises more questions than it answers.
Mechanical Micronization of Lipoaspirates: Squeeze and Emulsification Techniques.
Mashiko, Takanobu; Wu, Szu-Hsien; Feng, Jingwei; Kanayama, Koji; Kinoshita, Kaori; Sunaga, Ataru; Narushima, Mitsunaga; Yoshimura, Kotaro
2017-01-01
Condensation of grafted fat has been considered a key for achieving better outcomes after fat grafting. The authors investigated the therapeutic potential of two mechanical tissue micronizing procedures: squeeze and emulsification. Human aspirated fat was centrifuged (centrifuged fat) and fragmented with an automated slicer (squeezed fat). Alternatively, centrifuged fat was emulsified by repeated transfer between two syringes through a small-hole connecter and then separated by mesh filtration into two portions: residual tissue of emulsified fat and filtrated fluid of emulsified fat. The four products were examined for cellular components. Histologic and electron microscopic analyses revealed that squeezed fat and residual tissue of emulsified fat contained broken adipocytes and fragmented capillaries. Compared with centrifuged fat, the squeezed fat and residual fat products exhibited increased specific gravity and increased numbers of adipose-derived stem/stromal cells and endothelial cells per volume, suggesting successful cell/tissue condensation in both squeezed fat and residual tissue of emulsified fat. Although cell number and viability in the stromal vascular fraction were well maintained in both squeezed fat and residual fat, stromal vascular fraction culture assay showed that adipose-derived stromal cells were relatively damaged in residual tissue of emulsified fat but not in squeezed fat. By contrast, no adipose-derived stromal cells were cultured from filtrated fluid of emulsified fat. The authors' results demonstrated that mechanical micronization is easily conducted as a minimal manipulation procedure, which can condense the tissue by selectively removing adipocytes without damaging key components, such as adipose-derived stromal cells and endothelial cells. Depending on the extent of adipocyte removal, the product may be a useful therapeutic tool for efficient tissue volumization or therapeutic revitalization/fertilization. Therapeutic, V.
Quantum cryptography with squeezed states
Hillery, M
1999-01-01
A quantum key distribution scheme based on the use of displaced squeezed vacuum states is presented. The states are squeezed in one of two field quadrature components, and the value of the squeezed component is used to encode a character from an alphabet. The uncertainty relation between quadrature components prevents an eavesdropper from determining both with enough precision to determine the character being sent. Losses degrade the performance of this scheme, but it is possible to use phase-sensitive amplifiers to boost the signal and partially compensate for their effect.
Soft particles feel the squeeze
Frenkel, D.
2009-01-01
It's hard to fit in when you're different — especially if you're a large particle trying to squeeze into an array of smaller ones. But some soft, polymeric particles simply shrink to fit the space available.
CERN Bulletin
2012-01-01
Rare processes like the Higgs production require maximizing the number of proton collisions. This is done by squeezing the beams to very small sizes. However, interesting physics processes also happen when beams are not squeezed at interaction points. Last week, a dedicated run showed that the LHC is a record-breaking machine also with de-squeezed beams. This figure shows an online hit map of one of the ATLAS/ALFA detectors. The narrow elliptical shape is the typical signal produced by elastically scattered protons. The removal of the background (central bulge) is a challenge for both experiments. The beam squeezing parameter is known by experts as beta-star (ß*): the smaller the ß*, the stronger the squeezing. To obtain as many collisions as possible in the heart of the experiments, the ß* at full energy is 0.60 m – that is, beams are squeezed to very small beam sizes. This maximizes the rate of proton collisions as required for rare process...
Non-gaussian statistics from individual pulses of squeezed light
Wenger, J; Grangier, P
2004-01-01
We describe the observation of a degaussification protocol that maps individual pulses of squeezed light onto non-Gaussian states. This effect is obtained by sending a small fraction of the squeezed vacuum beam onto an avalanche photodiode, and by conditioning the single-shot homodyne detection of the remaining state upon the photon-counting events. The experimental data provides a clear evidence of phase-dependent non-Gaussian statistics. This protocol is closely related to the first step of an entanglement distillation procedure for continuous variables.
Non-Gaussian statistics from individual pulses of squeezed light.
Wenger, Jérôme; Tualle-Brouri, Rosa; Grangier, Philippe
2004-04-16
We describe the observation of a "degaussification" protocol that maps individual pulses of squeezed light onto non-Gaussian states. This effect is obtained by sending a small fraction of the squeezed vacuum beam onto an avalanche photodiode, and by conditioning the single-shot homodyne detection of the remaining state upon the photon-counting events. The experimental data provide clear evidence of phase-dependent non-Gaussian statistics. This protocol is closely related to the first step of an entanglement distillation procedure for continuous variables.
Controlling flexural waves in semi-infinite platonic crystals
Haslinger, Stewart G; Movchan, Alexander B; Jones, Ian S; Craster, Richard V
2016-01-01
We address the problem of scattering and transmission of a plane flexural wave through a semi-infinite array of point scatterers/resonators, which take a variety of physically interesting forms. The mathematical model accounts for several classes of point defects, including mass-spring resonators attached to the top surface of the flexural plate and their limiting case of concentrated point masses. We also analyse the special case of resonators attached to opposite faces of the plate. The problem is reduced to a functional equation of the Wiener-Hopf type, whose kernel varies with the type of scatterer considered. A novel approach, which stems from the direct connection between the kernel function of the semi-infinite system and the quasi-periodic Green's functions for corresponding infinite systems, is used to identify special frequency regimes. We thereby demonstrate dynamically anisotropic wave effects in semi-infinite platonic crystals, with particular attention paid to designing systems to exhibit dynami...
Squeezed light in optomechanical systems
DEFF Research Database (Denmark)
Harris, G. I.; Taylor, M. A.; Hoff, Ulrich Busk
2012-01-01
Squeezed light enhanced optomechanical measurements are demonstrated in both intra-cavity and biological contexts, with respective enhancements of 1.0 and 2.7 dB. Quantum enhanced microrheology of the cytoplasm of a yeast cell is thereby realized.......Squeezed light enhanced optomechanical measurements are demonstrated in both intra-cavity and biological contexts, with respective enhancements of 1.0 and 2.7 dB. Quantum enhanced microrheology of the cytoplasm of a yeast cell is thereby realized....
A platonic solid templating Archimedean solid: an unprecedented nanometre-sized Ag37 cluster
Li, Xiao-Yu; Su, Hai-Feng; Yu, Kai; Tan, Yuan-Zhi; Wang, Xing-Po; Zhao, Ya-Qin; Sun, Di; Zheng, Lan-Sun
2015-04-01
The spontaneous formation of discrete spherical nanosized molecules is prevalent in nature, but the authentic structural mimicry of such highly symmetric polyhedra from edge sharing of regular polygons has remained elusive. Here we present a novel ball-shaped {(HNEt3)[Ag37S4(SC6H4tBu)24(CF3COO)6(H2O)12]} cluster (1) that is assembled via a one-pot process from polymeric {(HNEt3)2[Ag10(SC6H4tBu)12]}n and CF3COOAg. Single crystal X-ray analysis confirmed that 1 is a Td symmetric spherical molecule with a [Ag36(SC6H4tBu)24] anion shell enwrapping a AgS4 tetrahedron. The shell topology of 1 belongs to one of 13 Archimedean solids, a truncated tetrahedron with four edge-shared hexagons and trigons, which are supported by a AgS4 Platonic solid in the core. Interestingly, the cluster emits green luminescence centered at 515 nm at room temperature. Our investigations have provided a promising synthetic protocol for a high-nuclearity silver cluster based on underlying geometrical principles.The spontaneous formation of discrete spherical nanosized molecules is prevalent in nature, but the authentic structural mimicry of such highly symmetric polyhedra from edge sharing of regular polygons has remained elusive. Here we present a novel ball-shaped {(HNEt3)[Ag37S4(SC6H4tBu)24(CF3COO)6(H2O)12]} cluster (1) that is assembled via a one-pot process from polymeric {(HNEt3)2[Ag10(SC6H4tBu)12]}n and CF3COOAg. Single crystal X-ray analysis confirmed that 1 is a Td symmetric spherical molecule with a [Ag36(SC6H4tBu)24] anion shell enwrapping a AgS4 tetrahedron. The shell topology of 1 belongs to one of 13 Archimedean solids, a truncated tetrahedron with four edge-shared hexagons and trigons, which are supported by a AgS4 Platonic solid in the core. Interestingly, the cluster emits green luminescence centered at 515 nm at room temperature. Our investigations have provided a promising synthetic protocol for a high-nuclearity silver cluster based on underlying geometrical principles
Research progress on squeeze casting in China
Institute of Scientific and Technical Information of China (English)
Li Yuanyuan; Zhang Weiwen; Zhao Haidong; You Dongdong; Zhang Datong; Shao Ming; Zhang Wen
2014-01-01
Squeeze casting is a technology with short route, high efficiency and precise forming, possessing features of casting and plastic processing. It is widely used to produce high performance metallic structural parts. As energy conservation and environmental protection concerns have risen, lightweight and high performance metal parts are urgently needed, which accelerated the development of squeeze casting technology over the past two decades in China. In this paper, research progress on squeeze casting aloys, typical parts manufacturing and development of squeeze casting equipment in China are introduced. The future trend and development priorities of squeeze casting are discussed.
Quantum Dynamical Theory for Squeezed Atom Laser
Institute of Scientific and Technical Information of China (English)
JING Hui; HAN Yi-Ang; CHEN Jing-Ling; MIAO Yuan-Xiu
2000-01-01
A model for the squeezed output coupler of the trapped Bose-Einstein condensed atoms is established with a simple many-boson system of two states with linear coupling, by preparing an initially squeezed light field. In the Bogoliubov approximation, its solutions show that the quadrature squeezing effect mutually oscillates between the coupling light field and the output atomic field. This manifests that the initially squeezed light will transform into a coherent state after some period of coupling interaction while the output atomic field is in a squeezed state.
Squeezed States and Helmholtz Spectra
Francisco Delgado, C; Reyes, M A; Mielnik, Bogdan; Reyes, Marco A
1997-01-01
The 'classical interpretation' of the wave function psi(x) reveals an interesting operational aspect of the Helmholtz spectra. It is shown that the traditional Sturm-Liouville problem contains the simplest key to predict the squeezing effect for charged particle states.
Longacre, R S
2016-01-01
Squeeze out happen when the expanding central fireball flows around a large surface flux tube in a central Au-Au collision at RHIC. We model such an effect in a flux tube model. Two particle correlations with respect to the $v_2$ axis formed by the soft fireball particles flowing around this large flux tube is a way of measuring the effect.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
We introduce the coordinate-dependent one- and two-mode squeezing transformations and discuss the properties of the corresponding one-and two-mode squeezed states. We show that the coordinate-dependent one-and two-mode squeezing transformations can be constructed by the combination of two transformations, a coordinate-dependent displacement followed by the standard squeezed transformation. Such a decomposition turns a nonlinear problem into a linear one because all the calculations involving the nonlinear one- and two-mode squeezed transformation have been shown to be able to reduce to those only concerning the standard one- and two-mode squeezed states.
Energy Technology Data Exchange (ETDEWEB)
Longacre, R. S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Physics Dept.
2016-09-01
Squeeze out happen when the expanding central fireball flows around a large surface flux tube in a central Au-Au collision at RHIC. We model such an effect in a flux tube model. Two particle correlations with respect to the v_{2} axis formed by the soft fireball particles flowing around this large flux tube is a way of measuring the effect.
Squeezing wetting and nonwetting liquids.
Samoilov, V N; Persson, B N J
2004-01-22
We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well defined molecular layers develop in the lubricant film when the thickness of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous, thermally activated changes in the number n of lubricant layers (n-->n-1 layering transitions). With increasing interaction energy between the octane bead units and the solid walls, the transitions from n to n-1 layers occur at higher average pressure. This results from the increasing activation barrier to nucleate the squeeze-out with increasing lubricant-wall binding energy (per unit surface area) in the contact zone. Thus, strongly wetting lubricant fluids are better boundary lubricants than the less wetting ones, and this should result in less wear. We analyze in detail the effect of capillary bridge formation (in the wetting case) and droplets formation (in the nonwetting case) on the forces exerted by the lubricant on the walls. For the latter case small liquid droplets may be trapped at the interface, resulting in a repulsive force between the walls during squeezing, until the solid walls come into direct contact, where the wall-wall interaction may be initially attractive. This effect is made use of in some practical applications, and we give one illustration involving conditioners for hair care application.
Readings of Platonic Virtue Theories from the Middle Ages to the Renaissance
DEFF Research Database (Denmark)
Catana, Leo
2014-01-01
It is commonly known that ancient schools of ethics were revived during the Renaissance: The texts pertaining to Platonic, Aristotelian, Stoic and Epicurean ethics were edited, translated and discussed in this period. It is less known that the Renaissance also witnessed a revival of Plotinian...... ethics, by then perceived as a legitimate form of Platonic ethics. Plotinus’ ethics had been transmitted through the Middle Ages through Macrobius’ Latin treatise In somnium Scipionis I.8, which relied heavily on Plotinus’ student, Porphyry, and his report of Plotinus’ ethics. In this article...... it is argued that the Florentine humanist and philosopher Marsilio Ficino carried on this tradition of Platonic, or rather Plotinian, ethics. He was familiar with Plotinus’ Enneads, since he had had access to it through Greek manuscripts from around 1462; his Latin translation of the Enneads was published...
Polarization squeezing with photonic crystal fibers
DEFF Research Database (Denmark)
Milanovic, J.; Huck, Alexander; Heersink, J.
2007-01-01
We report on the generation of polarization squeezing by employing intense, ultrashort light pulses in a single pass method in photonic crystal fibers. We investigated the squeezing behavior near the zero-dispersion wavelength and in the anomalous dispersion regime by using two distinct fibers. We...... observed a maximal squeezing at 810 nm of -3.3 +/- 0.3 dB with an excess noise of +16.8 +/- 0.3 dB in the anomalous regime. Correcting for linear and interference losses between the polarization modes, this corresponds to -6 +/- 1 dB. The ratio of squeezing to excess noise indicates the creation of a much...
Spin squeezing in nonlinear spin coherent states
Wang, Xiaoguang
2001-01-01
We introduce the nonlinear spin coherent state via its ladder operator formalism and propose a type of nonlinear spin coherent state by the nonlinear time evolution of spin coherent states. By a new version of spectroscopic squeezing criteria we study the spin squeezing in both the spin coherent state and nonlinear spin coherent state. The results show that the spin coherent state is not squeezed in the x, y, and z directions, and the nonlinear spin coherent state may be squeezed in the x and...
Efficient methods for solving discrete topology design problems in the PLATO-N project
DEFF Research Database (Denmark)
Canh, Nam Nguyen; Stolpe, Mathias
This paper considers the general multiple load structural topology design problems in the framework of the PLATO-N project. The problems involve a large number of discrete design variables and were modeled as a non-convex mixed 0–1 program. For the class of problems considered, a global optimizat......This paper considers the general multiple load structural topology design problems in the framework of the PLATO-N project. The problems involve a large number of discrete design variables and were modeled as a non-convex mixed 0–1 program. For the class of problems considered, a global...
Shukla, Namrata
2016-01-01
We study polarization squeezing of a pure photon number state which is obviously polarized but the mere change in the basis of polarization leads to simultaneous polarization squeezing in all the components of Stokes operator vector except those falling along or perpendicular to the direction of polarization state, is observed. We use the most general definition of polarization squeezing and discuss the experimental feasibility of the result. We also observe that a squeezing operation like non-degenerate parametric amplification of the state does not reveal simultaneous squeezing in all Stokes operator vectors and decreases in this sense.
Institute of Scientific and Technical Information of China (English)
Zhang Jing-Tao; He Guang-Qiang; Ren Li-Jie; Zeng Gui-Hua
2011-01-01
This paper investigates an analytical expression of teleportation fidelity in the teleportation scheme of a single mode of electromagnetic field. The fidelity between the original squeezed coherent state and the teleported one is expressed in terms of the squeezing parameter r and the quantum channel parameter (two-mode squeezed state) p. The results of analysis show that the fidelity increases with the increase of the quantum channel parameter p, while the fidelity decreases with the increase of the squeezing parameter r of the squeezed state. Thus the coherent state (r = 0)is the best quantum signal for continuous variable quantum teleportation once the quantum channel is built.
Teleportation of Squeezed Entangled State
Institute of Scientific and Technical Information of China (English)
HU Li-Yun; ZHOU Nan-Run
2007-01-01
Based on the coherent entangled state |α, x＞ we introduce the squeezed entangled state (SES). Then we propose a teleportation protocol for the SES by using Einstein-Podolsky-Rosen entangled state |η＞as a quantum channel.The calculation is greatly simplified by virtue of the Schmidt decompositions of both |α, x＞and |η＞. Any bipartite states that can be expanded in terms of |α, x＞may be teleported in this way due to the completeness of |α, x＞.
Parsing polarization squeezing into Fock layers
DEFF Research Database (Denmark)
Mueller, Christian R.; Madsen, Lars Skovgaard; Klimov, Andrei B.
2016-01-01
We investigate polarization squeezing in squeezed coherent states with varying coherent amplitudes. In contrast to the traditional characterization based on the full Stokes parameters, we experimentally determine the Stokes vector of each excitation subspace separately. Only for states with a fix...
30 years of squeezed light generation
DEFF Research Database (Denmark)
Andersen, Ulrik Lund; Gehring, Tobias; Marquardt, Christoph;
2016-01-01
Squeezed light generation has come of age. Significant advances on squeezed light generation have been made over the last 30 years—from the initial, conceptual experiment in 1985 till today’s top-tuned, application-oriented setups. Here we review the main experimental platforms for generating qua...
Nuclear spin squeezing via electric quadrupole interaction
Aksu Korkmaz, Yaǧmur; Bulutay, Ceyhun
2016-01-01
Control over nuclear-spin fluctuations is essential for processes that rely on preserving the quantum state of an embedded system. For this purpose, squeezing is a viable alternative, so far that has not been properly exploited for the nuclear spins. Of particular relevance in solids is the electric quadrupole interaction (QI), which operates on nuclei having spin higher than 1/2. In its general form, QI involves an electric-field gradient (EFG) biaxiality term. Here, we show that as this EFG biaxiality increases, it enables continuous tuning of single-particle squeezing from the one-axis twisting to the two-axis countertwisting limits. A detailed analysis of QI squeezing is provided, exhibiting the intricate consequences of EFG biaxiality. The initial states over the Bloch sphere are mapped out to identify those favorable for fast initial squeezing, or for prolonged squeezings. Furthermore, the evolution of squeezing in the presence of a phase-damping channel and an external magnetic field are investigated. We observe that dephasing drives toward an antisqueezed terminal state, the degree of which increases with the spin angular momentum. Finally, QI squeezing in the limiting case of a two-dimensional EFG with a perpendicular magnetic field is discussed, which is of importance for two-dimensional materials, and the associated beat patterns in squeezing are revealed.
Spin squeezing an ultracold molecule
Bhattacharya, M
2015-01-01
Most research on spin squeezing thus far has focused on realizations involving either atomic or nuclear degrees of freedom. In this article we discuss a concrete proposal for spin squeezing the ultracold ground state polar paramagnetic molecule OH, a system currently under fine control in the laboratory. Starting from an experimentally relevant effective Hamiltonian, we identify a parameter regime where different combinations of static electric and magnetic fields can be used to realize the single-axis twisting Hamiltonian of Kitagawa and Ueda [M. Kitagawa and M. Ueda, Phys. Rev. A 47, 5138 (1993)], the uniform field Hamiltonian proposed by Law et al. [C. K. Law, H. T Ng and P. T. Leung, Phys. Rev. A 63, 055601 (2001)], and a model of field propagation in a Kerr medium considered by Agarwal and Puri [G. S. Agarwal and R. R. Puri, Phys. Rev. A 39, 2969 (1989)]. To support our conclusions, we provide analytical expressions as well as numerical calculations, including optimization of field strengths and accounti...
Displacement of Propagating Squeezed Microwave States
Fedorov, Kirill G.; Zhong, L.; Pogorzalek, S.; Eder, P.; Fischer, M.; Goetz, J.; Xie, E.; Wulschner, F.; Inomata, K.; Yamamoto, T.; Nakamura, Y.; Di Candia, R.; Las Heras, U.; Sanz, M.; Solano, E.; Menzel, E. P.; Deppe, F.; Marx, A.; Gross, R.
2016-07-01
Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states remains constant over a wide range of the displacement power.
Integrated source of broadband quadrature squeezed light
DEFF Research Database (Denmark)
Hoff, Ulrich Busk; Nielsen, Bo Melholt; Andersen, Ulrik Lund
2015-01-01
An integrated silicon nitride resonator is proposed as an ultracompact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing...... squeezing spectrum for intra-cavity pump self-phase modulation. Subject to standard material loss and detection efficiencies, we find that the device holds promises for generating substantial quantum noise squeezing over a bandwidth exceeding 1 GHz. In the low-propagation loss regime, approximately -6 d...
Squeeze Film Damping for Aircraft Gas Turbines
Directory of Open Access Journals (Sweden)
R. W. Shende
1988-10-01
Full Text Available Modern aircraft gas turbine engines depend heavily on squeeze film damper supports at the bearings for abatement of vibrations caused by a number of probable excitation sources. This design ultimately results in light-weight construction together with higher efficiency and reliability of engines. Many investigations have been reported during past two decades concerning the functioning of the squeeze film damper, which is simple in construction yet complex in behaviour with its non-linearity and multiplicity of variables. These are reviewed in this article to throw light on the considerations involved in the design of rotor-bearing-casing systems incorporating squeeze film dampers.
Model on surface borehole squeezing deformation fracture*
Institute of Scientific and Technical Information of China (English)
SUN Hai-tao; HU Qian-ting; HUANG Sheng-shu
2009-01-01
As a good method to solve the problem of high methane on the workface and in the goaf, drawing coal strata methane through a surface borehole is used. However, the excavation affected the overlying rock strata greatly. When the excavation face passed through the surface borehole position, the surface borehole fractures fast. This problem was seriously related to the unformed squeeze effect. Therefore, a squeezing deformation fracture model based on the rock strata squeezing effect was set up. At the same time, a 3DEC simulation model is presented to confirm the theory. The result shows that the mod-el is reliable and has a good engineering application value.
Parity Breaking Medium and Squeeze Operators
Andrianov, A A; Soldati, R
2016-01-01
The transition between a Minkowski space region and a parity breaking medium domain is thoroughly discussed. The requirement of continuity of the field operator content across the separating boundary of the two domains leads to Bogolyubov transformations, squeezed pairs states and squeeze operators that turn out to generate a functional SU(2) algebra. According to this algebraic approach, the reflection and transmission probability amplitude across the separating boundary are computed. The suitable generalization of the well known Sauter-Schwinger-Nikishov formula to the emission or absorption of squeezed pairs out of the vacuum is obtained.
Coherent and squeezed states for the 3D harmonic oscillator
Mazouz, Amel; Bentaiba, Mustapha; Mahieddine, Ali
2017-01-01
A three-dimensional harmonic oscillator is studied in the context of generalized coherent states. We construct its squeezed states as eigenstates of linear contribution of ladder operators which are associated to the generalized Heisenberg algebra. We study the probability density to show the compression effect on the squeezed states. Our analysis reveals that squeezed states give us some freedom on the precise knowledge of position of the particle while maintaining the Heisenberg uncertainty relation minimum, squeezed states remains squeezed states over time.
Squeezing through: capsule or bubble?
Dawson, Geoffrey
2013-01-01
In this fluid dynamics video, we compare the deformation of two flexible particles as they propagate through a sudden constriction of a liquid filled channel under constant-flux flow: a gas bubble, and a capsule formed by encapsulating a liquid droplet in a cross-linked polymeric membrane. Both bubble and capsule adopt highly contorted configurations as they squeeze through the constriction, exhibit broadly similar features over a wide range of flow rates, and rupture for sufficiently high flow rates. However, at flow rates prior to rupture, certain features of the deformation allow bubble and capsule to be distinguished: bubbles exhibit a tip-streaming singularity associated with critical thinning of the rear of the bubble, while the capsule membrane wrinkles under large compressive stresses induced by the constriction.
Thermodynamics of squeezed states in mesoscopic circuits
Institute of Scientific and Technical Information of China (English)
Ji Ying-Hua; Luo Hai-Mei; Liu Qing; Lei Min-Sheng
2005-01-01
Based on the information theory, we present a density matrix to discuss coherent and squeezed states in a mesoscopic LC circuit with time-dependent frequency. With the relevant operators included in the density matrix, a connection between the appearance of coherent and squeezed states is established, i.e., the quantum state evolution of the system is closely related to the initial state. Generally speaking, due to the effect of environment temperature, the mesoscopic LC circuit will evolve to a squeezed state when it initially lies in an excited state. In particular, at a low temperature, step changes of circuit parameters will result in a squeezed minimum uncertainty state if the resonance frequency remains the same after the change.
Performance of quantum Otto refrigerators with squeezing.
Long, Rui; Liu, Wei
2015-06-01
The performance of a quantum Otto refrigerator coupled to a squeezed cold reservoir has been evaluated using the χ figure of merit. We have shown that squeezing can enhance the coefficient of performance (COP) dramatically, surpassing the Carnot COP defined by the initial temperatures of the heat baths. Furthermore, when the squeezing parameter approaches its maximum value, the work input vanishes while the cooling rate remains finite, in apparent contravention of the second law of thermodynamics. To explain this phenomenon, we have shown that squeezing renders the thermal bath into a nonequilibrium state and the temperature of the bath becomes frequency dependent. Thereby, a correlation to the Carnot COP has been deduced. The results reveal that the COP under the maximum χ figure of merit is of the Curzon-Ahlborn style that cannot surpass the actual Carnot COP, and is thus consistent with the second law of thermodynamics.
Displacement of squeezed propagating microwave states
Fedorov, Kirill G.; Zhong, Ling; Pogorzalek, Stefan; Eder, Peter; Fischer, Michael; Goetz, Jan; Wulschner, Friedrich; Xie, Edwar; Menzel, Edwin; Deppe, Frank; Marx, Achim; Gross, Rudolf
Displacement of propagating squeezed states is a fundamental operation for quantum communications. It can be applied to fundamental studies of macroscopic quantum coherence and has an important role in quantum teleportation protocols with propagating microwaves. We generate propagating squeezed states using a Josephson parametric amplifier and implement displacement using a cryogenic directional coupler. We study single- and two-mode displacement regimes. For the single-mode displacement we find that the squeezing level of the displaced squeezed state does not depend on the displacement amplitude. Also, we observe that quantum entanglement between two spatially separated channels stays constant across 4 orders of displacement power. We acknowledge support by the German Research Foundation through SFB 631 and FE 1564/1-1, the EU project PROMISCE, and Elite Network of Bavaria through the program ExQM.
Performance of quantum Otto refrigerators with squeezing
Long, Rui; Liu, Wei
2015-06-01
The performance of a quantum Otto refrigerator coupled to a squeezed cold reservoir has been evaluated using the χ figure of merit. We have shown that squeezing can enhance the coefficient of performance (COP) dramatically, surpassing the Carnot COP defined by the initial temperatures of the heat baths. Furthermore, when the squeezing parameter approaches its maximum value, the work input vanishes while the cooling rate remains finite, in apparent contravention of the second law of thermodynamics. To explain this phenomenon, we have shown that squeezing renders the thermal bath into a nonequilibrium state and the temperature of the bath becomes frequency dependent. Thereby, a correlation to the Carnot COP has been deduced. The results reveal that the COP under the maximum χ figure of merit is of the Curzon-Ahlborn style that cannot surpass the actual Carnot COP, and is thus consistent with the second law of thermodynamics.
Squeezing States of Magnons in a Ferromagnet
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
In this paper, we conduct an investigation into magnon self-squeezing states in a ferromagnet. In these states, the quantum fluctuations of the spin components can be lower than the zero-point quantum fluctuations of the coherent states. Through calculating the expectation values of spin fluctuations we gain the condition of achieving magnon self-squeezing. We introduce the mean-field theory for dealing with the nonlinear interaction term of Hamiltonian of magnon system.
Dynamics of squeezing from generalized coherent states
De Martino, S; Illuminati, F; De Martino, Salvatore; De Siena, Silvio; Illuminati, Fabrizio
1995-01-01
We extend the definition of generalized coherent states to include the case of time-dependent dispersion. We introduce a suitable operator providing displacement and dynamical rescaling from an arbitrary ground state. As a consequence, squeezing is naturally embedded in this framework, and its dynamics is ruled by the evolution equation for the dispersion. Our construction provides a displacement-operator method to obtain the squeezed states of arbitrary systems.
Energy Technology Data Exchange (ETDEWEB)
Secher, Bernard [French Atomic Energy Commission (CEA), Nuclear Energy Division (DEN) (France); CEA Saclay DM2S/SFME/LGLS, Bat. 454, F-91191 Gif-sur-Yvette Cedex (France)], E-mail: bsecher@cea.fr; Belliard, Michel [French Atomic Energy Commission (CEA), Nuclear Energy Division (DEN) (France); CEA Cadarache DER/SSTH/LMDL, Bat. 238, F-13108 Saint-Paul-lez-Durance Cedex (France); Calvin, Christophe [French Atomic Energy Commission (CEA), Nuclear Energy Division (DEN) (France); CEA Saclay DM2S/SERMA/LLPR, Bat. 470, F-91191 Gif-sur-Yvette Cedex (France)
2009-01-15
This paper describes a tool called 'Numerical Platon' developed by the French Atomic Energy Commission (CEA). It provides a freely available (GNU LGPL license) interface for coupling scientific computing applications to various freeware linear solver libraries (essentially PETSc, SuperLU and HyPre), together with some proprietary CEA solvers, for high-performance computers that may be used in industrial software written in various programming languages. This tool was developed as part of considerable efforts by the CEA Nuclear Energy Division in the past years to promote massively parallel software and on-shelf parallel tools to help develop new generation simulation codes. After the presentation of the package architecture and the available algorithms, we show examples of how Numerical Platon is used in sequential and parallel CEA codes. Comparing with in-house solvers, the gain in terms of increases in computation capacities or in terms of parallel performances is notable, without considerable extra development cost.
Platonic topology and CMB fluctuations: Homotopy, anisotropy, and multipole selection rules
Kramer, Peter
2009-01-01
The Cosmic Microwave Background CMB originates from an early stage in the history of the universe. Observed low multipole contributions of CMB fluctuations have motivated the search for selection rules from the underlying topology of 3-space. Everitt (2004) has generated all homotopies for Platonic spherical 3-manifolds by face gluings. We transform the glue generators into isomorphic deck transformations. The deck transformations act on a spherical Platonic 3-manifold as prototile and tile the 3-sphere by its images. A complete set of orthonormal functions on the 3-sphere is spanned by the Wigner harmonic polynomials. For a tetrahedral, two cubic and three octahedral manifolds we construct algebraically linear combinations of Wigner polynomials, invariant under deck transformations and with domain the manifold. We prove boundary conditions on polyhedral faces from homotopy. By algebraic means we pass to a multipole expansion. Assuming random models of the CMB radiation, we derive multipole selection rules, d...
Elementary abelian regular coverings of Platonic maps, Case I: ordinary representations
Jones, Gareth A
2012-01-01
We classify the orientably regular maps which are elementary abelian regular branched coverings of Platonic maps M, in the case where the covering group and the rotation group G of M have coprime orders. The method involves studying the representations of G on certain homology groups of the sphere, punctured at the branch-points. We give a complete classification for branching over faces (or, dually, vertices) of M, and outline how the method extends to other branching patterns.
Squeezing in the interaction of radiation with two-level atoms
Bandyopadhyay, Abir; Rai, Jagdish
1995-01-01
We propose a simple experimental procedure to produce squeezing and other non-classical properties like photon antibunching of radiation, and amplification without population inversion. The method also decreases the uncertainties of the angular-momentum quadratures representing the two-level atomic system in the interaction of the two-level atoms with quantized radiation.
SQUEEZE FLOW OF A SECOND-ORDER FLUID BETWEEN TWO PARALLEL DISKS OR TWO SPHERES
Institute of Scientific and Technical Information of China (English)
徐春晖; 黄文彬; 徐泳
2004-01-01
The normal viscous force of squeeze flow between two arbitrary rigid spheres with an interstitial second-order fluid was studied for modeling wet granular materials using the discrete element method. Based on the Reynolds' lubrication theory, the small parameter method was introduced to approximately analyze velocity field and stress distribution between the two disks. Then a similar procedure was carried out for analyzing the normal interaction between two nearly touching, arbitrary rigid spheres to obtain the pressure distribution and the resulting squeeze force. It has been proved that the solutions can be reduced to the case of a Newtonian fluid when the non-Newtonian terms are neglected.
The Second International Workshop on Squeezed States and Uncertainty Relations
Han, D. (Editor); Kim, Y. S.; Manko, V. I.
1993-01-01
This conference publication contains the proceedings of the Second International Workshop on Squeezed States and Uncertainty Relations held in Moscow, Russia, on 25-29 May 1992. The purpose of this workshop was to study possible applications of squeezed states of light. The Workshop brought together many active researchers in squeezed states of light and those who may find the concept of squeezed states useful in their research, particularly in understanding the uncertainty relations. It was found at this workshop that the squeezed state has a much broader implication than the two-photon coherent states in quantum optics, since the squeeze transformation is one of the most fundamental transformations in physics.
Complex Squeezing and Force Measurement Beyond the Standard Quantum Limit
Buchmann, L F; Kohler, J; Spethmann, N; Stamper-Kurn, D M
2016-01-01
A continuous quantum field, such as a propagating beam of light, may be characterized by a squeezing spectrum that is inhomogeneous in frequency. We point out that homodyne detectors, which are commonly employed to detect quantum squeezing, are blind to squeezing spectra in which the correlation between amplitude and phase fluctuations is complex. We find theoretically that such complex squeezing is a component of ponderomotive squeezing of light through cavity optomechanics. We propose a detection scheme, called synodyne detection, which reveals complex squeezing and allows its use to improve force detection beyond the standard quantum limit.
Quantum-squeezing effects of strained multilayer graphene NEMS
Directory of Open Access Journals (Sweden)
Wang Yuelin
2011-01-01
Full Text Available Abstract Quantum squeezing can improve the ultimate measurement precision by squeezing one desired fluctuation of the two physical quantities in Heisenberg relation. We propose a scheme to obtain squeezed states through graphene nanoelectromechanical system (NEMS taking advantage of their thin thickness in principle. Two key criteria of achieving squeezing states, zero-point displacement uncertainty and squeezing factor of strained multilayer graphene NEMS, are studied. Our research promotes the measured precision limit of graphene-based nano-transducers by reducing quantum noises through squeezed states.
Atomic Tunnelling Dynamics of Two Squeezed Bose-Einstein Condensates
Institute of Scientific and Technical Information of China (English)
LI Jin-Hui; KUANG Le-Man
2003-01-01
In this paper, tunnelling dynamics of squeezed Bose-Einstein condensates (BEC's) in the presence of the nonlinear self-interaction of each species, the interspecies nonlinear interaction, and the Josephson-like tunnelling interaction is investigated by using the second quantization approach. The influence of BEC squeezing on macroscopic quantum self-trapping (MQST) and quantum coherent atomic tunnelling is analyzed in detail. It is shown that the MQST and coherent atomic tunnelling between two squeezed BEC's can be manipulated through changing squeezing amplitude and squeezing phase of BEC squeezed states.
Squeezed quadrature fluctuations in a gravitational wave detector using squeezed light.
Dwyer, S; Barsotti, L; Chua, S S Y; Evans, M; Factourovich, M; Gustafson, D; Isogai, T; Kawabe, K; Khalaidovski, A; Lam, P K; Landry, M; Mavalvala, N; McClelland, D E; Meadors, G D; Mow-Lowry, C M; Schnabel, R; Schofield, R M S; Smith-Lefebvre, N; Stefszky, M; Vorvick, C; Sigg, D
2013-08-12
Squeezed states of light are an important tool for optical measurements below the shot noise limit and for optical realizations of quantum information systems. Recently, squeezed vacuum states were deployed to enhance the shot noise limited performance of gravitational wave detectors. In most practical implementations of squeezing enhancement, relative fluctuations between the squeezed quadrature angle and the measured quadrature (sometimes called squeezing angle jitter or phase noise) are one limit to the noise reduction that can be achieved. We present calculations of several effects that lead to quadrature fluctuations, and use these estimates to account for the observed quadrature fluctuations in a LIGO gravitational wave detector. We discuss the implications of this work for quantum enhanced advanced detectors and even more sensitive third generation detectors.
Knox, D. J.
2013-11-14
© 2013 © The authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved. The squeeze-film flow of a thin layer of Newtonian fluid filling the gap between a flat impermeable surface moving under a prescribed constant load and a flat thin porous bed coating a stationary flat impermeable surface is considered. Unlike in the classical case of an impermeable bed, in which an infinite time is required for the two surfaces to touch, for a porous bed contact occurs in a finite contact time. Using a lubrication approximation, an implicit expression for the fluid layer thickness and an explicit expression for the contact time are obtained and analysed. In addition, the fluid particle paths are calculated, and the penetration depths of fluid particles into the porous bed are determined. In particular, the behaviour in the asymptotic limit of small permeability, in which the contact time is large but finite, is investigated. Finally, the results are interpreted in the context of lubrication in the human knee joint, and some conclusions are drawn about the contact time of the cartilage-coated femoral condyles and tibial plateau and the penetration of nutrients into the cartilage.
LHC Report: Freshly squeezed beams!
Mike Lamont for the LHC Team
2011-01-01
After careful validation of new machine settings, the LHC was ready for higher luminosity operation. New luminosity records have been set, but the operations team continues to wrestle with machine availability issues. The commissioning of the squeeze to a ß* of 1 m in ATLAS and CMS described in the last Bulletin took until Wednesday, 7 September to complete. In order to validate the new set-up, beam losses were provoked in a controlled way with low intensity beams. The distribution of beam loss around the machine in these tests is known as a loss map. The loss maps showed that the collimation system is catching the large majority of beam losses as it should, and that the machine was ready for us to ramp the number of bunches back up and go to physics production. The ramp-up of the number of bunches went smoothly with fills at 264, 480, and 912 bunches on the way back to the machine’s previous record of 1380 bunches (first fill on Friday, 9 Se...
LHC Report: Preparing for a tighter squeeze
Jan Uythoven for the LHC Team
2011-01-01
The LHC is resuming operation after a planned period of machine development followed by a technical stop. The beams returned last Friday, in the evening of 2 September, and preparations are now being made to squeeze the beams further at the collision points, aiming for new luminosity records. To obtain as many collisions as possible in the heart of the experiments, the beams are squeezed to very small beam sizes. The beam squeezing parameter is known by experts as beta-star: the smaller the ß*, the stronger the squeezing. During the machine development period that started on 24 August, tests were made for the high-luminosity experiments ATLAS and CMS with ß* values of 1 m instead of the 1.5 m used previously. Unfortunately these tests were only partially successful, as some of the beam was lost during the squeezing process. It is thought that the beam losses were caused by the collimators, which were moved closer to the beam, and by the reduced crossing angle of the beams at ...
Relationship between squeezing and entangled state transformations
Fan Hong Yi
2003-01-01
We show that c-number dilation transform in the Einstein-Podolsky-Rosen (EPR) entangled state, i.e. vertical bar eta sub 1 , eta sub 2) -> vertical bar eta sub 1 , eta sub 2 /mu) (or vertical bar eta sub 1 , eta sub 2) -> vertical bar eta sub 1 /mu, eta sub 2)), maps onto a kind of one-sided two-mode squeezing operator exp left brace i lambda/2(P sub 1 + P sub 2)(Q sub 1 + Q sub 2) - lambda/2 right brace, (or exp left brace i lambda/2(P sub 1 - P sub 2)(Q sub 1 - Q sub 2) - lambda/2 right brace). Using the IWOP technique, we derive their normally ordered form and construct the corresponding squeezed states. In doing so, some new relationship between squeezing and entangled state transformation is revealed. The dynamic Hamiltonian for such a kind of squeezing evolution is derived. The properties and application of the one-sided squeezed state are briefly discussed. These states can also be obtained with the use of a beam splitter.
Continuous squeeze casting process by mass production
Institute of Scientific and Technical Information of China (English)
Yun Xia; Rich Jacques
2006-01-01
Squeeze casting has become the most competitive casting process in the automotive industry because of its many advantages over high pressure die casting (HPDC). Many squeeze casting R & D and small amount volume making have been implemented around the world, but the mass production control still exists problem. SPX Contech squeeze casting process P2000 successfully achieved the goal of mass production; it includes lower metal turbulence, less gas entrapment, minimum volumetric shrinkage, and thus less porosity. Like other casting processes, however, the quality of squeeze castings is still sensitive to process control and gate and runner design. Casting defects can form in both die-filling and metal solidification phases. The occurrence of casting defects is directly attributed to improper adjustment or lack of control of process parameters including metal filling velocity, temperature, dwell time, cooling pattern, casting design, and etc. This paper presents examples using P2000 techniques to improve part quality in the following areas: runner & gate design, casting & runner layout in the die, squeeze pin application, high thermal conductivityinserts, cooling/heating systems, spray & lubricant techniques,and part stress calculation from shrinkage or displacement prediction after stress relief.
Squeezing in the Real and Imaginary Spin Coherent States
Institute of Scientific and Technical Information of China (English)
YAN Dong; WANG Xiao-Guang; WU Ling-An
2005-01-01
@@ We study spin squeezing properties in the real and imaginary spin coherent states. We obtain analytical expressions of two spin squeezing parameters via a novel ladder operator formalism of the spin coherent state and the generation function method.
Minimum uncertainty and squeezing in diffusion processes and stochastic quantization
Demartino, S.; Desiena, S.; Illuminati, Fabrizo; Vitiello, Giuseppe
1994-01-01
We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.
Spin Squeezing of One-Axis Twisting Model
Li, Song-Song
2017-09-01
We investigate spin squeezing of the one-axis twisting model. By using short-time approximation solutions of the angular momentum operators, we analytically and numerically calculate the spin squeezing parameter. It is shown that smaller linear interaction can produce a stronger spin squeezing and maintain a longer time interval. It is also shown that the stronger spin squeezing can be achieved by increasing the number of particles.
Entropy Squeezing in the Quantum Heisenberg XY Spin Chains
Institute of Scientific and Technical Information of China (English)
CHANG Ping; SHAO Bin; ZOU Jian
2009-01-01
The time evolution of entropy squeezing for the two-qubit XYZ Heisenberg model in an external uniform magnetic field is investigated in the language of quantum information.The effect of different parameters such as magnetic field and anisotropy parameter on the properties of entropy squeezing and variance squeezing are discussed.It is shown that magnetic field and anisotropy parameter can enhance the entropy squeezing.
Leggett-Garg Inequalities for Squeezed States
Martin, Jerome
2016-01-01
Temporal Bell inequalities, or Leggett-Garg Inequalities (LGI), are studied for continuous-variable systems placed in a squeezed state. The importance of those systems lies in their broad applicability which allows the description of many different physical settings in various branches of physics, ranging from cosmology to condensed matter physics and from optics to quantum information theory. LGI violations are explored and systematically mapped in squeezing parameter space. Configurations for which LGI violation occurs are found but it is shown that no violation can be obtained if all squeezing angles vanish, contrary to what happens for the spatial Bell inequalities. We also assess the effect of decoherence on the detectability of such violations. Our study opens up the possibility of new experimental designs for the observation of LGI violation.
On the Squeezed Number States and their Phase Space Representations
Albano, L; Stephany, J
2002-01-01
We compute the photon number distribution, the Q distribution function and the wave functions in the momentum and position representation for a single mode squeezed number state. We discuss the oscillations which appear in the photon number distribution of squeezed number states for high values of the squeezing parameter. We compare our results with the formalism based on the interference in phase space.
Coordinate-Dependent N-Mode Squeezing Transformations
Institute of Scientific and Technical Information of China (English)
ZHANG Wei; REN Gang; CHEN Xiang-Rong; SONG Tong-Qiang; CAI Ling-Cang; GOU Qing-Quan
2008-01-01
We introduce the coordinate-dependent N-mode squeezing transformation and show that it can be con-structed by the combination of two unitary transformations, a coordinate-dependent displacement followed by the stan-dard squeezed transformation. The properties of the corresponding N-mode squeezed states are also discussed.
Generation and detection of squeezed state
Institute of Scientific and Technical Information of China (English)
SHANG Xu-dong; YU Li; FENG Xue-dong; YANG Bo-jun
2008-01-01
Soliton amplitude squeezed state is obtained and dctected by using asymmetric Sagnac interferometer and balanced homodyne detecting system.An improved photo detector circuit for quantum state detection is introduced.The circuit has a bandwidth of 10MHz and the saturation power is about 19 mW.A maximum photocurrent noise reduction of 1.1 dB below the shot noise is achieved.Taking the detection efficiency into account,the squeezing will be about 1.5 dB.
Directory of Open Access Journals (Sweden)
Sonja Weiss
2009-07-01
Full Text Available The article presents the leading Platonic doctrines of the embodied soul, examining the relation between their Orphic and Pythagorean roots and Plotinus’ correction of the Neo-Pythagorean pessimism on the one hand, and Gnostic solutions of the problem on the other. The analysis of certain Gnostic passages clearly shows that, in spite of Plotinus’ anti-Gnostic polemic, some of the ideas proposed by the philosopher as an alternative to his opponents’ pessimism are also present in the Gnostic descriptions of the emanation from the first Principle and the multiplication of the Eons. The article focuses on the passages which, avoiding an ethical valuation of the generation and multiplication process, limit the concept of sin to the human domain, where it belongs in Plotinus’ view as well. Moreover, the article endeavours to throw light on some of the most controversial themes, which were to remain irreconcilable despite a number of tenets shared by both sides.
Squeezing the limit: quantum benchmarks for the teleportation and storage of squeezed states
Energy Technology Data Exchange (ETDEWEB)
Owari, M; Plenio, M B [Institute for Mathematical Sciences, 53 Prince' s Gate, Imperial College London, London SW7 2PG (United Kingdom); Polzik, E S; Wolf, M M [Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, DK-2100 Copenhagen Oe (Denmark); Serafini, A [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)], E-mail: m.owari@imperial.ac.uk
2008-11-15
We derive fidelity benchmarks for the quantum storage and teleportation of squeezed states of continuous variable systems, for input ensembles where the degree of squeezing s is fixed, no information about its orientation in phase space is given, and the distribution of phase-space displacements is a Gaussian. In the limit where the latter becomes flat, we prove analytically that the maximal classical achievable fidelity (which is 1/2 without squeezing, for s=1) is given by {radical}s/(1+s), vanishing when the degree of squeezing diverges. For mixed states, as well as for general distributions of displacements, we reduce the determination of the benchmarks to the solution of a finite-dimensional semidefinite program, which yields accurate, certifiable bounds thanks to a rigorous analysis of the truncation error. This approach may be easily adapted to more general ensembles of input states.
El Triangulo de Platon y El Factor Gnomonico: Una aplicacion a los oraculos de Herodoto
Perez-Enriquez, Raul
2013-01-01
A modification to the gnomonic factor using the concept of triangle of Plato is presented. With the aid of the platonic gnomonic factor (fgp) as we called it, we find that the oracles mentioned by Herodotus in his History, Dodona in Greece and Ammon in Oasis Siwa, Libya, were placed there because the noon shadow of Sun of a gnomon formed, back in 2500BC, the triangle of Plato the former, and the Egyptian sacred triangle the latter. This means that both concepts were known by Egyptians form Th...
Vacuum squeezing in atomic media with self-rotation
Matsko, A B; Scully, M O; Welch, G R; Budker, D; Kimball, D F; Rochester, S M; Yashchuk, V V
2002-01-01
When linearly polarized light propagates through a medium which causes self-rotation of elliptically polarized light, squeezed vacuum is produced in the orthogonal polarization. A simple relationship between the self-rotation angle for a given ellipticity and the degree of squeezing is developed. Taking into account absorption, we find the optimum condition for squeezing for any medium which causes self-rotation. Next, we analyze squeezing when the medium consists of a vapor of idealized, four-level atoms. Finally, we consider a medium consisting of a gas of multi-level Rb atoms, and analyze squeezing for light tuned near the D-lines under realistic conditions.
Squeezed light for advanced gravitational wave detectors and beyond.
Oelker, E; Barsotti, L; Dwyer, S; Sigg, D; Mavalvala, N
2014-08-25
Recent experiments have demonstrated that squeezed vacuum states can be injected into gravitational wave detectors to improve their sensitivity at detection frequencies where they are quantum noise limited. Squeezed states could be employed in the next generation of more sensitive advanced detectors currently under construction, such as Advanced LIGO, to further push the limits of the observable gravitational wave Universe. To maximize the benefit from squeezing, environmentally induced disturbances such as back scattering and angular jitter need to be mitigated. We discuss the limitations of current squeezed vacuum sources in relation to the requirements imposed by future gravitational wave detectors, and show a design for squeezed light injection which overcomes these limitations.
Engineering Matter Interactions Using Squeezed Vacuum
Directory of Open Access Journals (Sweden)
Sina Zeytinoğlu
2017-06-01
Full Text Available Virtually all interactions that are relevant for atomic and condensed matter physics are mediated by quantum fluctuations of the electromagnetic field vacuum. Consequently, controlling the vacuum fluctuations can be used to engineer the strength and the range of interactions. Recent experiments have used this premise to demonstrate novel quantum phases or entangling gates by embedding electric dipoles in photonic cavities or wave guides, which modify the electromagnetic fluctuations. Here, we show theoretically that the enhanced fluctuations in the antisqueezed quadrature of a squeezed vacuum state allow for engineering interactions between electric dipoles without the need for a photonic structure. Thus, the strength and range of the interactions can be engineered in a time-dependent way by changing the spatial profile of the squeezed vacuum in a traveling-wave geometry, which also allows the implementation of chiral dissipative interactions. Using experimentally realized squeezing parameters and including realistic losses, we predict single-atom cooperativities C of up to 10 for the squeezed-vacuum-enhanced interactions.
Squeeze Casting of Steel Weapon Components
1976-09-01
equipment. The squeeze casting process also differs from rheo- casting.(10-12) Unlike the former, the rheocasting process (8) "Ferrous Die Casting...various phases of rheocasting . At least so far, the process has not been applied to fabrication of complex steel components of the type that are under
Squeezing of Collective Excitations in Spin Ensembles
DEFF Research Database (Denmark)
Kraglund Andersen, Christian; Mølmer, Klaus
2012-01-01
We analyse the possibility to create two-mode spin squeezed states of two separate spin ensembles by inverting the spins in one ensemble and allowing spin exchange between the ensembles via a near resonant cavity field. We investigate the dynamics of the system using a combination of numerical an...
Squeezing in a 2-D generalized oscillator
Castanos, Octavio; Lopez-Pena, Ramon; Manko, Vladimir I.
1994-01-01
A two-dimensional generalized oscillator with time-dependent parameters is considered to study the two-mode squeezing phenomena. Specific choices of the parameters are used to determine the dispersion matrix and analytic expressions, in terms of standard hermite polynomials, of the wavefunctions and photon distributions.
Hartogs figure and symplectic non-squeezing
Sukhov, A
2011-01-01
We solve a problem on filling by Levi-flat hypersurfaces for a class of totally real 2-tori in a real 4-manifold with an almost complex structure tamed by an exact symplectic form. As an application we obtain a simple proof of Gromov's non-squeezing theorem in dimension 4 and new results on rigidity of symplectic structures.
Integrated source of broadband quadrature squeezed light
DEFF Research Database (Denmark)
Hoff, Ulrich Busk; Nielsen, Bo Melholt; Andersen, Ulrik Lund
2015-01-01
An integrated silicon nitride resonator is proposed as an ultracompact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing...
Limits of noise squeezing in Kerr effect
Bajer, J; Tanas, R
2002-01-01
It is well known that the optical Kerr effect can be a source of highly squeezed light, however the analytical limit of the noise suppression has not been found yet. The process is reconsidered and an analytical estimation of the optimal quadrature noise level is presented. The validity of the new scaling law is checked numerically and analytically.
Quantum teleportation of entangled squeezed vacuum states
Institute of Scientific and Technical Information of China (English)
蔡新华
2003-01-01
An optical scheme for probabilistic teleporting entangled squeezed vacuum states (SVS) is proposed. In this scheme,the teleported state is a bipartite entangled SVS,and the quantum channel is a tripartite entangled SVS.The process of the teleportation is achieved by using a 50/50 symmetric beamsplitter and photon detectors with the help of classical information.
Squeezing more from a quantum nondemolition measurement
DEFF Research Database (Denmark)
Buchler, B.C.; Lam, P.K.; Bachor, H.A.
2002-01-01
We use a stable, 5 dB, amplitude squeezed source for a quantum nondomolition (QND) experiment. The performance of our QND system is enhanced by an electro-optic feedforward loop which improve,, the signal transfer efficiency. At best, we measure a total signal transfer of 1.81 and conditional var...
Single-mode squeezing in arbitrary spatial modes
Semmler, Marion; Chille, Vanessa; Gabriel, Christian; Banzer, Peter; Aiello, Andrea; Marquardt, Christoph; Leuchs, Gerd
2016-01-01
As the generation of squeezed states of light has become a standard technique in laboratories, attention is increasingly directed towards adapting the optical parameters of squeezed beams to the specific requirements of individual applications. It is known that imaging, metrology, and quantum information may benefit from using squeezed light with a tailored transverse spatial mode. However, experiments have so far been limited to generating only a few squeezed spatial modes within a given setup. Here, we present the generation of single-mode squeezing in Laguerre-Gauss and Bessel-Gauss modes, as well as an arbitrary intensity pattern, all from a single setup using a spatial light modulator (SLM). The degree of squeezing obtained is limited mainly by the initial squeezing and diffractive losses introduced by the SLM, while no excess noise from the SLM is detectable at the measured sideband. The experiment illustrates the single-mode concept in quantum optics and demonstrates the viability of current SLMs as fl...
Li, Xi-Zeng; Su, Bao-Xia
1994-01-01
It is found that two-mode output quantum electromagnetic field in two-mode squeezed states exhibits higher-order squeezing to all even orders. And the generalized uncertainty relations are also presented for the first time. The concept of higher-order squeezing of the single-mode quantum electromagnetic field was first introduced and applied to several processes by Hong and Mandel in 1985. Lately Li Xizeng and Shan Ying have calculated the higher-order squeezing in the process of degenerate four-wave mixing and presented the higher-order uncertainty relations of the fields in single-mode squeezed states. In this paper we generalize the above work to the higher-order squeezing in two-mode squeezed states. The generalized uncertainty relations are also presented for the first time.
El Triangulo de Platon y El Factor Gnomonico: Una aplicacion a los oraculos de Herodoto
Perez-Enriquez, Raul
2013-01-01
A modification to the gnomonic factor using the concept of triangle of Plato is presented. With the aid of the platonic gnomonic factor (fgp) as we called it, we find that the oracles mentioned by Herodotus in his History, Dodona in Greece and Ammon in Oasis Siwa, Libya, were placed there because the noon shadow of Sun of a gnomon formed, back in 2500BC, the triangle of Plato the former, and the Egyptian sacred triangle the latter. This means that both concepts were known by Egyptians form Thebes long before they were formalized by the Greeks. The right angled triangle concept is an idealization, as said by D. Magdolen, of an astronomical observation; i. e. it is the shadow cast by a gnomon. ----- Se presenta una modificacion al factor gnomonico usando el concepto de triangulo de Platon. Con la ayuda de lo que llamamos factor gnomonico platonico (fgp) nosotros encontramos que los oraculos mencionados por Herodoto en su Historia, Dodona en Grecia, y Ammon en el Oasis Siwa, Libia, fueron ubicados ahi porque, ha...
Khudaverdian, H M
2016-01-01
We notice that one of the Diophantine equations, $knm=2kn+2km+2nm$, arising in the universality originated Diophantine classification of simple Lie algebras, has interesting interpretations for two different sets of signs of variables. In both cases it describes "regular polyhedrons" with $k$ edges in each vertex, $n$ edges of each face, with total number of edges $|m|$, and Euler characteristics $\\chi=\\pm 2$. In the case of negative $m$ this equation corresponds to $\\chi=2$ and describes true regular polyhedrons, Platonic solids. The case with positive $m$ corresponds to Euler characteristic $\\chi=-2$ and describes the so called equivelar maps (charts) on the surface of genus $2$. In the former case there are two routes from Platonic solids to simple Lie algebras - abovementioned Diophantine classification and McKay correspondence. We compare them for all solutions of this type, and find coincidence in the case of icosahedron (dodecahedron), corresponding to $E_8$ algebra. In the case of positive $k$, $n$ an...
Optimal Signal Filtration in Optical Sensors with Natural Squeezing of Vacuum Noises
Gusev, A. V.; Kulagin, V. V.
1996-01-01
The structure of optimal receiver is discussed for optical sensor measuring a small displacement of probe mass. Due to nonlinear interaction of the field and the mirror, a reflected wave is in squeezed state (natural squeezing), two quadratures of which are correlated and therefore one can increase signal-to-noise ratio and overcome the SQL. A measurement procedure realizing such correlation processing of two quadratures is clarified. The required combination of quadratures can be produced via mixing of pump field reflected from the mirror with local oscillator phase modulated field in duel-detector homodyne scheme. Such measurement procedure could be useful not only for resonant bar gravitational detector but for laser longbase interferometric detectors as well.
Generating Squeezed States in Solid State Circuits
Institute of Scientific and Technical Information of China (English)
REN Xin-An; WEN Yi-Huo; ZHANG Li-You; LONG Gui-Lu
2008-01-01
We propose a scheme for generating squeezed states in solid state circuits which consist a superconducting transmission line resonator (STLR), a superconducting Cooper-pair box (CPB) and a nanoelectromechanical resonator (NMR). The nonlinear interaction between the STLR and the CPB can be implemented by setting the external biased flux of the CPB at some certain points. The interaction Hamiltonian between the STLR and the NMR is derived by performing Fr 5hlich transformation on the total Hamiltonian of the combined system. Just by adiabatically keeping the CPB at the ground state, we get the standard parametric down-conversion Hamiltonian, and the squeezed states of the STLR can be easily generated, which is similar to the three-wave mixing in quantum optics.
Squeezing and Entanglement in Continuous Variable Systems
Institute of Scientific and Technical Information of China (English)
XIA Yun-Jie; GUO Guang-Can
2004-01-01
Based on total variance of a pair of Einstein-Podolsky-Rosen (EPR) type operators, the generalized EPR entangled states in continuous variable systems are defined. We show that such entangled states must correspond to two-mode squeezing states whether these states are Gaussian or not and whether they are pure or not. With help of the relation between the total variance and the entanglement, the degree of such entanglement is also defined. Through analysing some specific cases, we see that this method is very convenient and easy in practical applications. In addition, an entangled state with no squeezing is studied, which reveals that there certainly exists something unknown about entanglement in continuous variable systems.
Limits to squeezing in the degenerate OPO
Chaturvedi, S; Drummond, P D
2001-01-01
We develop a systematic theory of quantum fluctuations in the driven parametric oscillator (OPO), including the region near threshold. This allows us to treat the limits imposed by nonlinearities to quantum squeezing and noise reduction, in this non-equilibrium quantum phase-transition. In particular, we compute the squeezing spectrum near threshold, and calculate the optimum value. We find that the optimal noise reduction occurs at different driving fields, depending on the ratio of damping rates. The largest spectral noise reductions are predicted to occur with a very high-Q second-harmonic cavity. Our analytic results agree well with stochastic numerical simulations. We also compare the results obtained in the positive-P representation, as a fully quantum mechanical calculation, with the truncated Wigner phase space equation, also known as semiclassical theory.
Adaptive phase estimation with squeezed thermal light
DEFF Research Database (Denmark)
Berni, A. A.; Madsen, Lars Skovgaard; Lassen, Mikael Østergaard
2013-01-01
Summary form only given. The use of quantum states of light in optical interferometry improves the precision in the estimation of a phase shift, paving the way for applications in quantum metrology, computation and cryptography. Sub-shot noise phase sensing can for example be achieved by injecting...... a squeezed vacuum into an interferometer . However, this approach leads to enhanced sensitivity only for small phase shifts. In this work we aim for ab initio sub-shot noise estimation of an unknown phase shift using a pre-determined squeezed probe and an adaptive measurement approach. We experimentally...... with the signal. A second estimation step leads to the final estimation of the phase shift. Thermalization of the probe state prevents the attainability of the quantum Cramér-Rao bound. Nevertheless, we show that the studied adaptive scheme still saturates the classical Cramér-Rao bound, showing sub-shot noise...
Squeeze Casting of Semiolid A356 Alloy
Directory of Open Access Journals (Sweden)
Xiang-Jie Yang
2014-05-01
Full Text Available The rheo-squeeze casting (rheo-SQC combining the rheocasting and the SQC was developed, in which semisolid slurry was produced by the low superheat pouring with a shearing field (LSPSF process. The three-dimensional morphology of the primary α-Al phase and the rest spacing of slurry prepared by LSPSF process have been reconstructed and visualized, and the microstructures of squeeze cast A356 alloy have been obtained. Based on the three-dimensional microstructure reconstructed, their three-dimensional characterizations such as solid volume fraction and equivalent diameter of the extracted primary α-Al phase of the slurry were measured and calculated. And the microstructures of cross-section of squeeze cast product were investigated. Compared and analyzed the typical microstructure characteristics of parts in different positions produced by SQC and rheo-SQC, the results show that the primary α-Al phase was in the form of enriched dendrites across the whole section of parts produced by SQC. Nevertheless, in the relative case of the rheo-SQC, the whole formations of dendrites have been inhibited effectively, revealing a conspicuous modification in morphology and refinement of the primary α-Al phase. In addition, the solid fraction decreased from the centre to the verge of products along the slurry flow orientation.
Observation of Localized Multi-Spatial-Mode Quadrature Squeezing
Directory of Open Access Journals (Sweden)
C. S. Embrey
2015-07-01
Full Text Available Quantum states of light can improve imaging whenever the image quality and resolution are limited by the quantum noise of the illumination. In the case of a bright illumination, quantum enhancement is obtained for a light field composed of many squeezed transverse modes. A possible realization of such a multi-spatial-mode squeezed state is a field which contains a transverse plane in which the local electric field displays reduced quantum fluctuations at all locations, on any one quadrature. Using a traveling-wave amplifier, we have generated a multi-spatial-mode squeezed state and showed that it exhibits localized quadrature squeezing at any point of its transverse profile, in regions much smaller than its size. We observe 75 independently squeezed regions. The amplification relies on nondegenerate four-wave mixing in a hot vapor and produces a bichromatic squeezed state. The result confirms the potential of this technique for producing illumination suitable for practical quantum imaging.
Properties of squeezing functions and geometry of bounded domains
Deng, Fusheng; Zhang, Liyou
2012-01-01
In this article we continue the study of properties of squeezing functions and geometry of bounded domains. The limit of squeezing functions of a sequence of bounded domains is studied. We give comparisons of intrinsic positive forms and metrics on bounded domains in terms of squeezing functions. To study the boundary behavior of squeezing functions, we introduce the notions of (intrinsic) ball pinching radius, and give boundary estimate of squeezing functions in terms of these datum. Finally, we use these results to study geometric and analytic properties of some interesting domains, including planar domains, Cartan-Hartogs domains, and a strongly pseudoconvex Reinhardt domain which is not convex. As a corollary, all Cartan-Hartogs domains are homogenous regular, i.e., their squeezing functions admit positive lower bounds.
Complex Squeezing and Force Measurement Beyond the Standard Quantum Limit.
Buchmann, L F; Schreppler, S; Kohler, J; Spethmann, N; Stamper-Kurn, D M
2016-07-15
A continuous quantum field, such as a propagating beam of light, may be characterized by a squeezing spectrum that is inhomogeneous in frequency. We point out that homodyne detectors, which are commonly employed to detect quantum squeezing, are blind to squeezing spectra in which the correlation between amplitude and phase fluctuations is complex. We find theoretically that such complex squeezing is a component of ponderomotive squeezing of light through cavity optomechanics. We propose a detection scheme called synodyne detection, which reveals complex squeezing and allows the accounting of measurement backaction. Even with the optomechanical system subject to continuous measurement, such detection allows the measurement of one component of an external force with sensitivity only limited by the mechanical oscillator's thermal occupation.
Squeezing and entanglement in multi-qutrit systems
Naji, Azita; Jafarpour, Mojtaba
2013-08-01
We study squeezing and bipartite entanglement in a multi-qutrit system initially in a coherent state, initiated by the two-axis counter-twisting Hamiltonian in the presence and also absence of a magnetic field. We start with an initial coherent state which is neither squeezed nor entangled; however, it gains both properties as it is evolved by the Hamiltonian. Both squeezing and entanglement show an oscillatory behavior in time and stronger Hamiltonians correspond to smaller oscillation periods. Generation of almost continuous squeezing according to Kitagawa criterion seems feasible; however, off and on squeezing death is observed according to that of Wineland. The entanglement is diminished as the size of the system is increased, implying that the generation of strong entanglement in large multi-qutrit systems, instigated by the counter-twisting Hamiltonian, may not be feasible. Application of a magnetic field may have adverse effect on both squeezing and entanglement.
Experimental Realization of a Thermal Squeezed State of Levitated Optomechanics
Rashid, Muddassar; Tufarelli, Tommaso; Bateman, James; Vovrosh, Jamie; Hempston, David; Kim, M. S.; Ulbricht, Hendrik
2016-12-01
We experimentally squeeze the thermal motional state of an optically levitated nanosphere by fast switching between two trapping frequencies. The measured phase-space distribution of the center of mass of our particle shows the typical shape of a squeezed thermal state, from which we infer up to 2.7 dB of squeezing along one motional direction. In these experiments the average thermal occupancy is high and, even after squeezing, the motional state remains in the remit of classical statistical mechanics. Nevertheless, we argue that the manipulation scheme described here could be used to achieve squeezing in the quantum regime if preceded by cooling of the levitated mechanical oscillator. Additionally, a higher degree of squeezing could, in principle, be achieved by repeating the frequency-switching protocol multiple times.
Generalised squeezing and information theory approach to quantum entanglement
Vourdas, A.
1993-01-01
It is shown that the usual one- and two-mode squeezing are based on reducible representations of the SU(1,1) group. Generalized squeezing is introduced with the use of different SU(1,1) rotations on each irreducible sector. Two-mode squeezing entangles the modes and information theory methods are used to study this entanglement. The entanglement of three modes is also studied with the use of the strong subadditivity property of the entropy.
On the realization of atomic dipole squeezing by remote manipulation
Institute of Scientific and Technical Information of China (English)
XIANG Shao-hua; SONG Ke-hui
2004-01-01
A scheme for adjusting the dipole squeezing properties of one atom at one place by manipulating and detecting another atom at the remote place is proposed, in which these atoms initially in the spatially separated entangled state act as a quantum channel carrying quantum information. The result shows that the dipole squeezing properties of one atom can be adjusted by rotating and detecting the other, and the maximal atomic squeezing can be obtained under local operation and classical communication.
Quantum electrodynamics in the squeezed vacuum state Electron mass shift
Putz, V; Putz, Volkmar; Svozil, Karl
2001-01-01
Due to the nonvanishing average photon population of the squeezed vacuum state, finite corrections to the scattering matrix are obtained. The lowest order contribution to the electron mass shift for a one mode squeezed vacuum state is given by $\\delta m(\\Omega, s)/m=\\alpha (2/\\pi)(\\Omega /m)^2\\sinh^2(s)$, where $\\Omega$ and $s$ stand for the mode frequency and the squeeze parameter and $\\alpha$ for the fine structure constant, respectively.
Distillation of the two-mode squeezed state.
Kurochkin, Yury; Prasad, Adarsh S; Lvovsky, A I
2014-02-21
We experimentally demonstrate entanglement distillation of the two-mode squeezed state obtained by parametric down-conversion. Applying the photon annihilation operator to both modes, we raise the fraction of the photon-pair component in the state, resulting in the increase of both squeezing and entanglement by about 50%. Because of the low amount of initial squeezing, the distilled state does not experience significant loss of Gaussian character.
Simulations and experiments on polarization squeezing in optical fiber
DEFF Research Database (Denmark)
Corney, J.F.; Heersink, J.; Dong, R.;
2008-01-01
We investigate polarization squeezing of ultrashort pulses in optical fiber, over a wide range of input energies and fiber lengths. Comparisons are made between experimental data and quantum dynamical simulations to find good quantitative agreement. The numerical calculations, performed using both...... effects cause a marked deterioration of squeezing at higher energies and longer fiber lengths. We also calculate the optimum fiber length for maximum squeezing....
Squeezed state generation for interferometric gravitational-wave detection
Energy Technology Data Exchange (ETDEWEB)
McKenzie, Kirk; Gray, Malcolm B; Gossler, Stefan; Lam, Ping Koy; McClelland, David E [Center for Gravitational Physics, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia)
2006-04-21
In this paper we present results demonstrating the development of a squeezed state at sideband frequencies as low as 100 Hz. The squeezed source was generated in a doubly resonant optical parametric oscillator (OPO) operated below threshold. The OPO resonance condition is achieved using the pump field, allowing the OPO to produce a squeezed vacuum state stably. We describe limitations to the experiment and discuss future work.
On the squeezed number states and their phase space representations
Energy Technology Data Exchange (ETDEWEB)
Albano, L [Universidad Simon Bolivar, Departamento de Fisica, Apartado Postal 89000, Caracas 1080-A (Venezuela); Mundarain, D F [Universidad Simon Bolivar, Departamento de Fisica, Apartado Postal 89000, Caracas 1080-A (Venezuela); Stephany, J [Universidad Simon Bolivar, Departamento de Fisica, Apartado Postal 89000, Caracas 1080-A (Venezuela)
2002-10-01
We compute the photon-number distribution, the Q({alpha}) distribution function and the wavefunctions in the momentum and position representation for a single mode squeezed number state using generating functions which allow one to obtain any matrix element in the squeezed number state representation from the matrix elements in the squeezed coherent state representation. For highly squeezed number states we discuss the previously unnoted oscillations which appear in the Q({alpha}) function. We also note that these oscillations can be related to the photon-number distribution oscillations and to the momentum representation of the wavefunction.
Study on heat treatment blister of squeeze casting parts
Institute of Scientific and Technical Information of China (English)
TONG Wen-jun; QI Lin; QI Pi-xiang
2007-01-01
Heat treatment blister is one of the common defects found in squeeze casting parts, which is related to squeeze mode, process and mold. For direct squeeze-casting parts, solution heat treatment can be performed smoothly as long as oil-based paint is not used and air exhaust is well arranged. For indirect squeeze casting parts,solution heat treatment can also be applied when additional factors are taken into consideration, including well designed internal feeding system and strictly controlled liquid metal filling velocity to prevent from inclusions.
Hybrid squeezing of solitonic resonant radiation in photonic crystal fibers
Tran, Truong X; Soeller, Christoph; Blow, Keith J; Biancalana, Fabio
2011-01-01
We report on the existence of a novel kind of squeezing in photonic crystal fibers which is conceptually intermediate between the four-wave mixing induced squeezing, in which all the participant waves are monochromatic waves, and the self-phase modulation induced squeezing for a single pulse in a coherent state. This hybrid squeezing occurs when an arbitrary short soliton emits quasi-monochromatic resonant radiation near a zero group velocity dispersion point of the fiber. Photons around the resonant frequency become strongly correlated due to the presence of the classical soliton, and a reduction of the quantum noise below the shot noise level is predicted.
The properties of squeezed optical states created in lossy cavities
Seifoory, Hossein; Dignam, Marc M; Sipe, J E
2016-01-01
We investigate theoretically the properties of squeezed states generated using degenerate parametric down conversion in lossy cavities. We show that the Lindblad master equation, which governs the evolution of this system, has as its solution a squeezed thermal state with an effective temperature and squeezing parameter that depends on time. We derive analytical solutions for the time-evolution of quadrature noise, thermal photon number, squeezing parameter, and total photon number under different pumping regimes. We also find the steady state limits of the quadrature noises and discuss the $ g^{(2)} $ factor of the generated light inside the cavity in the steady state.
Triple-mode squeezing with dressed six-wave mixing.
Wen, Feng; Li, Zepei; Zhang, Yiqi; Gao, Hong; Che, Junling; Che, Junling; Abdulkhaleq, Hasan; Zhang, Yanpeng; Wang, Hongxing
2016-05-12
The theory of proof-of-principle triple-mode squeezing is proposed via spontaneous parametric six-wave mixing process in an atomic-cavity coupled system. Special attention is focused on the role of dressed state and nonlinear gain on triple-mode squeezing process. Using the dressed state theory, we find that optical squeezing and Autler-Towns splitting of cavity mode can be realized with nonlinear gain, while the efficiency and the location of maximum squeezing point can be effectively shaped by dressed state in atomic ensemble. Our proposal can find applications in multi-channel communication and multi-channel quantum imaging.
Rainer Knab, Platons Siebter Brief. Einleitung, Text, Übersetzung, Kommentar
Brisson, Luc
2016-01-01
Cette traduction commentée de la septième Lettre attribuée à Platon est un objet étrange. On y trouve imprimé le texte édité par Burnet en 1905, mais on ne trouve rien sur l’édition de Souilhé aux Belles Lettres en 1926 ni celle de J. Moore-Blunt chez Teubner en 1985. De surcroît, la bibliographie qui clôt le volume fait montre d’incroyables faiblesses en ce qui concerne les traductions et les commentaires utilisés. Dans l’introduction, R. Knab admet, mais sans apporter d’arguments nouveaux,...
Efficient methods for solving discrete topology design problems in the PLATO-N project
DEFF Research Database (Denmark)
Canh, Nam Nguyen; Stolpe, Mathias
This paper considers the general multiple load structural topology design problems in the framework of the PLATO-N project. The problems involve a large number of discrete design variables and were modeled as a non-convex mixed 0–1 program. For the class of problems considered, a global...... optimization method based on the branch-and-cut concept was developed and implemented. In the method a large number of continuous relaxations were solved. We also present an algorithm for generating cuts to strengthen the quality of the relaxations. Several heuristics were also investigated to obtain efficient...... algorithms. The branch and cut method is used to solve benchmark examples which can be used to validate other methods and heuristics....
Queen Christina’s esoteric interests as a background to her Platonic Academies
Directory of Open Access Journals (Sweden)
Susanna Åkerman
2008-01-01
Full Text Available In 1681 the blind quietist, Francois Malaval, stated that Queen Christina of Sweden late in life had ‘given up’ [Hermes] Trismegistos and the Platonists, in favour of the Church fathers. The statement does not explain what role the Church fathers were to play in her last years, but it does show that Christina really had been interested in the rather elitist and esoteric doctrine of Hermetic Platonic Christianity. In this article the author looks at her library to show the depth of this Hermetic involvement. Her interest serves as a background to her life as ex-queen in Italy after her famous abdication from the Swedish throne in 1654, when she was 27 years old.
Structure and binding in crystals of cage-like molecules: hexamine and platonic hydrocarbons
Berland, Kristian; 10.1063/1.3366652
2010-01-01
In this paper, we show that first-principle calculations using a van der Waals density functional (vdW-DF), [Phys. Rev. Lett. $\\mathbf{92}$, 246401 (2004)] permits determination of molecular crystal structure. We study the crystal structures of hexamine and the platonic hydrocarbons (cubane and dodecahedrane). The calculated lattice parameters and cohesion energy agree well with experiments. Further, we examine the asymptotic accounts of the van der Waals forces by comparing full vdW-DF with asymptotic atom-based pair potentials extracted from vdW-DF. The character of the binding differ in the two cases, with vdW-DF giving a significant enhancement at intermediate and relevant binding separations. We analyze consequences of this result for methods such as DFT-D, and question DFT-D's transferability over the full range of separations.
Hermeneutics and the philosophy of medicine: Hans-Georg Gadamer's platonic metaphor.
Lingiardi, V; Grieco, A
1999-09-01
Taking as our starting point Plato's metaphor of the doctor as philosopher we reflect on some aspects of the epistemological status of medicine. The framework to this paper is the hermeneutics of Hans-Georg Gadamer which shows the paradoxical nature of Western medicine in choosing the body-object as its investigative starting point, while in actual fact dealing with subjects. Gadamer proposes a model of medicine as the art of understanding and dialogue, which is capable of bringing together its various constituent parts, i.e. knowledge, knowing how to do and knowing how to be, in medical practice and in the physician's training. The paper concludes with a brief discussion of the dyadic figure of the physician as Platonic "master of the living totality" and wounded healer, capable of activating the patient's self-healing capacity.
Squeezing-enhanced optomechanical transduction sensitivity
DEFF Research Database (Denmark)
Hoff, Ulrich Busk; Harris, Glen I.; Madsen, Lars Skovgaard;
2013-01-01
High-sensitivity interferometric detection of mechanical displacements has received much attention over the past decades, due to its vast field of applicability, e.g. in gravitational wave detection, cantilever-based single spin detection, and the quest to reveal quantum effects in mesoscopic...... mechanical systems. Following the proposal of Caves we have experimentally proven the applicability of squeezed light-enhanced interferometric displacement detection in the domain of micromechanical oscillators. The technique has previously been demonstrated for table-top interferometer setups and GW...
MHD squeezing flow between two infinite plates
Directory of Open Access Journals (Sweden)
Umar Khan
2014-03-01
Full Text Available Magneto hydrodynamic (MHD squeezing flow of a viscous fluid has been discussed. Conservation laws combined with similarity transformations have been used to formulate the flow mathematically that leads to a highly nonlinear ordinary differential equation. Analytical solution to the resulting differential equation is determined by employing Variation of Parameters Method (VPM. Runge–Kutta order-4 method is also used to solve the same problem for the sake of comparison. It is found that solution using VPM reduces the computational work yet maintains a very high level of accuracy. The influence of different parameters is also discussed and demonstrated graphically.
Experimental Demonstration of Squeezed State Quantum Averaging
Lassen, Mikael; Sabuncu, Metin; Filip, Radim; Andersen, Ulrik L
2010-01-01
We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.
Squeezed Wave Packets in Quantum Cosmology
Pedram, Pouria
2010-11-01
We use an appropriate initial condition for constructing squeezed wave packets in the context of Wheeler-DeWitt equation with complete classical description. This choice of initial condition does not alter the classical paths and only affect the quantum mechanical picture. To demonstrate the method, we consider an empty 4+1-dimensional Kaluza-Klein quantum cosmology in the presence of a negative cosmological constant. We show that these wave packets do not disperse and sharply peak on the classical trajectories in the whole configuration space. So, the probability of finding the corresponding physical quantities approaches zero everywhere except on the classical paths.
Oscillatory squeeze flow for the study of linear viscoelastic behavior
DEFF Research Database (Denmark)
Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole
2016-01-01
The squeezing of a sample between parallel plates has been used for many years to characterize the rheological behavior of soft, purely viscous materials, and in recent times, small-amplitude oscillatory squeezing has been proposed as a means to determine the linear viscoelastic properties of mol...
Critical Petermann K factor for intensity noise squeezing
van der Lee, A.M.; van Druten, N.J.; van Exter, M.P.; Woerdman, J.P.; Poizat, J.P.; Grangier, P.
2000-01-01
We investigate the impact of the Petermann-excess-noise factor K >= 1 on the possibility of intensity noise squeezing of laser light below the standard quantum limit. Using an N-mode model, we show that squeezing is limited to a floor level of 2(K-1) times the shot noise limit. Thus, even a modest P
Entanglement bounds for squeezed non-symmetric thermal state
Jiang, L
2003-01-01
I study the three parameters bipartite quantum Gaussian state called squeezed asymmetric thermal state, calculate Gaussian entanglement of formation analytically and the up bound of relative entropy of entanglement, compare them with coherent information of the state. Based on the result obtained, it is anticipated that hashing inequality is not violated for squeezed non-symmetric thermal state.
Spin-Squeezing Entanglement of Second-Harmonic Generation
Shu, Jian
2016-10-01
An experimentally feasible scheme for generating spin-squeezing entanglement via second-harmonic generation was presented. Its shown that spin-squeezing entanglement can be generated rapidly in the dynamical process by adjusting coupling constant, detuning, the total number of particles and the evolution time.
Physical Activity Benefits Creativity: Squeezing a Ball for Enhancing Creativity
Kim, JongHan
2015-01-01
Studies in embodied cognition show that physical sensations, such as touch and movement, influence cognitive processes. Two studies were conducted to test whether squeezing a soft versus a hard ball facilitates different types of creativity. Squeezing a malleable ball would increase divergent creativity by catalyzing multiple or alternative ideas,…
Enforcing Margin Squeeze Ex Post Across Converging Telecommunications Markets
DEFF Research Database (Denmark)
Bergqvist, Christian; Townsend, John
A margin squeeze is an exclusionary abuse which occurs when a vertically Integrated telecoms operator creates a disparity between upstream and downstream prices with the intention of squeezing an access competitor’s profits. The purpose of such pricing is either to increase the latter’s entry cos...
Experimental Realisation of a Thermal Squeezed State of Levitated Optomechanics
Rashid, Muddassar; Bateman, James; Vovrosh, Jamie; Hempston, David; Kim, M S; Ulbricht, Hendrik
2016-01-01
We experimentally squeeze the thermal motional state of an optically levitated nanosphere, by fast switching between two trapping frequencies. The measured phase space distribution of our particle shows the typical shape of a squeezed thermal state, from which we infer up to 2.7dB of squeezing along one motional direction. The experiment features a large number of thermal excitations, therefore remaining in the classical regime. Nevertheless, we argue that the manipulation scheme described here could be used to achieve squeezing below the zero-point level, if preceded by ground state cooling of the levitated mechanical oscillator. Additionally, a higher degree of squeezing could in principle be achieved by repeating the frequency-switching protocol multiple times.
Resonance Fluorescence from an Artificial Atom in Squeezed Vacuum
Directory of Open Access Journals (Sweden)
D. M. Toyli
2016-07-01
Full Text Available We present an experimental realization of resonance fluorescence in squeezed vacuum. We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier. We investigate the fluorescence spectra in the weak and strong driving regimes, observing up to 3.1 dB of reduction of the fluorescence linewidth below the ordinary vacuum level and a dramatic dependence of the Mollow triplet spectrum on the relative phase of the driving and squeezed vacuum fields. Our results are in excellent agreement with predictions for spectra produced by a two-level atom in squeezed vacuum [Phys. Rev. Lett. 58, 2539 (1987], demonstrating that resonance fluorescence offers a resource-efficient means to characterize squeezing in cryogenic environments.
Quantum Harmonic Oscillator State Control in a Squeezed Fock Basis
Kienzler, D.; Lo, H.-Y.; Negnevitsky, V.; Flühmann, C.; Marinelli, M.; Home, J. P.
2017-07-01
We demonstrate control of a trapped-ion quantum harmonic oscillator in a squeezed Fock state basis, using engineered Hamiltonians analogous to the Jaynes-Cummings and anti-Jaynes-Cummings forms. We demonstrate that for squeezed Fock states with low n the engineered Hamiltonians reproduce the √{n } scaling of the matrix elements which is typical of Jaynes-Cummings physics, and also examine deviations due to the finite wavelength of our control fields. Starting from a squeezed vacuum state, we apply sequences of alternating transfer pulses which allow us to climb the squeezed Fock state ladder, creating states up to excitations of n =6 with up to 8.7 dB of squeezing, as well as demonstrating superpositions of these states. These techniques offer access to new sets of states of the harmonic oscillator which may be applicable for precision metrology or quantum information science.
Nth-powered amplitude squeezing in fan-states
Duc, T M
2002-01-01
Squeezing properties of the Hillery-type N-powered amplitude are investigated in the fan-state vertical bar xi; 2k, f> sub F which is linearly superposed by 2k 2k-quantum nonlinear coherent states in the phase-locked manner. The general expression of squeezing is derived analytically for arbitrary xi, k, N and f showing a multi-directional character of squeezing. For a given k, squeezing may appear to the even power N=2k if f ident to 1 and N>=2k if f not =1 and the number of directions along with the Nth-powered amplitude is squeezed is exactly equal to N, for both f ident to 1 (the light field) and f not =1 (the vibrational motion of the trapped ion). Discussions are also given elucidating the qualitative difference between the cases of f ident to 1 and f not =1.
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2011-05-01
Full Text Available Secondo alcune fonti antiche il sofista Protagora, ormai anziano, fu accusato, come Socrate, di empietà e trovò la morte lasciando Atene, forse per sfuggire al processo o forse perché bandito dalla città. Contro questa tradizione sembra militare la testimonianza di Platone, secondo la quale, almeno in apparenza, Protagora, a differenza di altri intellettuali, non si [...
Magnetorheological Damper Working in Squeeze Mode
Directory of Open Access Journals (Sweden)
Xinglong Gong
2014-05-01
Full Text Available This research is focused on evaluation of the magnetorheological fluids (MRFs based damper which works in squeeze mode. The operation direction of this damper is parallel to the direction of the external magnetic field. Before testing, commercial software ANSYS was used to analyze the magnetic field distribution inside the damper generated by charging current in the coil. The performance of the damper was tested by using the MTS809 (produced by MTS Systems Corporation, USA. For simulation of this damper, a mathematical model was set up. Experimental results showed that the small squeezed MR damper could produce large damping force; for example, the maximum damping force is nearly 6 kN, while the amplitude is 1.2 mm, the frequency is 1.0 Hz, and the current is 2.0 A, and the damping force was controllable by changing the current in the coil. The damping force versus displacement curves are complex. We divide them into four regions for simulation. The maximum damper force increased quickly with the increasing of the current in coil. This kind of damper can be used in vibration isolation for precise equipment.
Controllable hybrid shape of correlation and squeezing
Abdisa, Garuma; Ahmed, Irfan; Wang, Xiuxiu; Liu, Zongchen; Wang, Hongxing; Zhang, Yanpeng
2016-08-01
Two- and three-mode correlation and squeezing of spontaneous parametric four-wave mixing (SPFWM) and fourth-order fluorescence (FL) composite signals are investigated theoretically and experimentally in both homonuclear (two-level) and heteronuclearlike (V-type level) molecular systems of P r3 + :YSO. By selecting different time positions, changing the power, and changing the frequency detuning of the laser field, the competition between the composite signals is demonstrated. It is found that as the laser parameters change, the signal evolves from a nonlinear χ(4 ) process resulting in a FL signal to a SPFWM signal (χ(3 ) process). In addition, the competition effect between the signals determines the evolution of the shape of the correlation from a pure sharp to a two-stage (mixed) shape and finally to a pure broad peak amplitude. Furthermore, the signal evolution determines the magnitude of squeezing, which can control the noise level. Such progress may find potential applications in optical hybrid communication and information processing.
Partial squeeze film levitation modulates fingertip friction.
Wiertlewski, Michaël; Fenton Friesen, Rebecca; Colgate, J Edward
2016-08-16
When touched, a glass plate excited with ultrasonic transverse waves feels notably more slippery than it does at rest. To study this phenomenon, we use frustrated total internal reflection to image the asperities of the skin that are in intimate contact with a glass plate. We observed that the load at the interface is shared between the elastic compression of the asperities of the skin and a squeeze film of air. Stroboscopic investigation reveals that the time evolution of the interfacial gap is partially out of phase with the plate vibration. Taken together, these results suggest that the skin bounces against the vibrating plate but that the bounces are cushioned by a squeeze film of air that does not have time to escape the interfacial separation. This behavior results in dynamic levitation, in which the average number of asperities in intimate contact is reduced, thereby reducing friction. This improved understanding of the physics of friction reduction provides key guidelines for designing interfaces that can dynamically modulate friction with soft materials and biological tissues, such as human fingertips.
Institute of Scientific and Technical Information of China (English)
安钧鸿; 王顺金; 罗洪刚; 贾成龙
2004-01-01
The dissipative and decoherence properties as well as the asymptotic behaviour of the single mode electromagnetic field interacting with the time-dependent squeezed vacuum field reservoir are investigated in detail by using the algebraic dynamical method. With the help of the left and right representations of the relevant hw( 4) algebra, the dynamical symmetry of the nonautonomous master equation of the system is found to be su(1, 1). The unique equilibrium steady solution is found to be the squeezed state and any initial state of the system is proven to approach the unique squeezed state asymptotically. Thus the squeezed vacuum field reservoir is found to play the role of a squeezing mold of the cavity field.
Critical petermann K factor for intensity noise squeezing
van Der Lee AM; van Druten NJ; van Exter MP; Woerdman; Poizat; Grangier
2000-11-27
We investigate the impact of the Petermann-excess-noise factor K>/=1 on the possibility of intensity noise squeezing of laser light below the standard quantum limit. Using an N-mode model, we show that squeezing is limited to a floor level of 2(K-1) times the shot noise limit. Thus, even a modest Petermann factor significantly impedes squeezing, which becomes impossible when K>/=1.5. This appears as a serious limitation for obtaining sub-shot-noise light from practical semiconductor lasers. We present experimental evidence for our theory.
Direct Measurement of Squeezing in the Motion of Trapped Ions
Institute of Scientific and Technical Information of China (English)
ZENG Hao-Sheng; HU Ai-Qin; LIU Qiong; KUANG Le-Man
2005-01-01
@@ We present a simple method that can be used to directly measure the squeezing of the quantum motional states of a trapped ion.Through the use of the interaction between the trapped ion and classical lasers, one can design a required coupling between the internal electronic and external vibrational degrees of freedom of the ion and can transfer information of the expectation value of a vibrational operator to the atomic internal populations.Thus measurement of squeezing on the quantum motional state can directly be realized.By adjusting the phases of the interacting lasers, one can measure the squeezing of both position and momentum quadratures.
Studying fluid squeeze characteristics for aerostatic journal bearing
Energy Technology Data Exchange (ETDEWEB)
Abdel-Rahman, Gamal M. [Department of Mathematics, Faculty of Science, Benha University, Benha 13518 (Egypt)], E-mail: gamalm60@yahoo.com
2008-07-01
The Reynolds equation for studying fluid squeeze of aerostatic journal bearing is solved numerically by considering the quasi-steady behavior of the air film. The radial displacement can influence the air film thickness modifying the pressure distribution in the journal-bearing gap. Also, the variations in the seal characteristics with eccentricity, time, squeeze number, length-to-diameter and supply pressure are presented. The numerical results for the squeeze load-carrying capacity are given in a non-dimensional for000.
Bell operator and Gaussian squeezed states in noncommutative quantum mechanics
Bastos, Catarina; Bertolami, Orfeu; Dias, Nuno Costa; Prata, João Nuno
2015-01-01
One examines putative corrections to the Bell operator due to the noncommutativity in the phase-space. Starting from a Gaussian squeezed envelop whose time evolution is driven by commutative (standard quantum mechanics) and noncommutative dynamics respectively, one concludes that, although the time evolving covariance matrix in the noncommutative case is different from the standard case, the squeezing parameter dominates and there are no noticeable noncommutative corrections to the Bell operator. This indicates that, at least for squeezed states, the privileged states to test Bell correlations, noncommutativity versions of quantum mechnics remains as non-local as quantum mechanics itself.
Bell operator and Gaussian squeezed states in noncommutative quantum mechanics
Bastos, Catarina; Bernardini, Alex E.; Bertolami, Orfeu; Dias, Nuno Costa; Prata, João Nuno
2016-05-01
We examine putative corrections to the Bell operator due to the noncommutativity in the phase space. Starting from a Gaussian squeezed envelope whose time evolution is driven by commutative (standard quantum mechanics) and noncommutative dynamics, respectively, we conclude that although the time-evolving covariance matrix in the noncommutative case is different from the standard case, the squeezing parameter dominates and there are no noticeable noncommutative corrections to the Bell operator. This indicates that, at least for squeezed states, the privileged states to test Bell correlations, noncommutativity versions of quantum mechanics remain as nonlocal as quantum mechanics itself.
Preparation of entangled squeezed states and quantification of their entanglement
Institute of Scientific and Technical Information of China (English)
蔡新华; 匡乐满
2002-01-01
We propose a scheme for generating bipartite and multipartite entangled squeezed states via the Jaynes-Cummingsmodel with large detuning. Bipartite entanglement of these entangled states is quantified by the concurrence. We alsouse the N-tangle to compute multipartite entanglement of these multipartite entangled squeezed states. Finally wediscuss two limiting cases which arise from r → oo and r → 0, in which the multipartite entangled squeezed statereduces correspondingly into an N-qubit Greenberger-Horne-Zeilinger state and an N-qubit W state.
The Achromatic Telescopic Squeezing (ATS) MD part III
Fartoukh, S; Goddard, B; Hofle, W; Jacquet, D; Kruk, G; Lamont, M; de Maria, R; Miyamoto, R; Mueller, G; Pojer, M; Ponce, L; Redaelli, S; Ryckx, N; Steinhagen, R; Strzelczyk, M; Vanbavinckhove, G; Wenninger, J
2011-01-01
This note highlights the results obtained during the third so-called ATS MD which took place in 2011. The goal of this MD was extremely challenging, targeting a pre-squeezed beta* of 40 cm in ATLAS and CMS, followed by a telescopic squeeze of these two insertions to finally reach a beta* of 10 cm both at IP1 and IP5. Due to the rather poor machine availability during the MD period, the time initially allocated to the ATS studies was hardly cut by a factor of 2, and "only" the achromatic pre-squeeze down to beta*=40 cm was demonstrated with beam.
On structuralism, and the poststructuralistic condition in Deleuze, inverter of Platonism
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Manuel Altamirano
2016-11-01
Full Text Available Focusing on Gilles Deleuze´s second stage of thought, specially his work of inversion of Platonism, we´ll show why the concept of structure is so important, as well as its conditions and functioning, and how this characterization has an impact on central concepts such as identity or difference. That way we´ll understand the idealistic character of Deleuze´s philosophy, thus a different kind of Plato´s idealism. We´ll take into consideration, also, the realm of the “problematic”, and the “ideal game”. We´ll evaluate the six necessary criteria of what Deleuze calls an “Idea”. Given the conditions we´ll establish trough this revision, we´ll be able to conclude that Deleuze overtakes structuralism and embraces poststructuralism. This last affirmation will be argued trough a comparison between Delezue´s poststructuralism and the basics of more classical, Lévi-Straus´s structuralism
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Mikhailova N. V.
2015-01-01
Full Text Available The author of the work proposes a philosophical and methodological interpretation of the mathematical objects, using the system triad of the main directions of substantiation of mathematics: the formalism of Hilbert, Brouwer’s intuitionism and Godel’s Platonism. The need for these directions in the concept of substantiation of mathematics from the point of view of the current state of the philosophy of mathematics is shown on the mathematical examples. The philosophical and methodological analysis of objects of mathematics has never been unambiguous, therefore in this paper the results of studies of philosophers, logicians and mathematicians, in which the problem of substantiation is explicated in the context of trends in the development of mathematics, are used. Their professional view on philosophical characteristics of the objects of mathematics contributes to the identification of the unity of all mathematical knowledge maintaining the initial mathematical base of knowledge and revealing new ways of integrating the directions of substantiation in the philosophy of mathematics. The practical problem of substantiation of mathematics is realized through the elaboration of metatheoretical knowledge under the paradigm shift in the philosophy of mathematics to the productive direction from analysis to synthesis.
Platonism, cartesianism and Hegel’s thought in the Matrix Trilogy
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Milidrag Predrag
2013-01-01
Full Text Available In this article I will try to interpret changes in Neo, the main character in The Matrix Trilogy, against the background of the ideas of Plato and Descartes, as well as Hegel’s from his Philosophy of History and The Phenomenology of Spirit. Although “philosophical” The Matrix Trilogy is not long-winded and boring film: instead of talking endlessly, the characters are working ceaselessly, and that work is changing them. Contrary to widespread opinion, this interpretation does not find the presence of Descartes’ hyperbolic doubt in the first part of trilogy, but first film sees as a pure Platonism. Nevertheless, there are the Cartesian motifs (e.g. dualism, freeing mind from preconceived opinions, acquiring different habits of belief. The result of the first film is the position of Hegelian unhappy consciousness. This is just a preparation for the key moment of whole Trilogy that is the dialogue between Neo and Architect. Neo’s decision to chose to save Trinity is interpreted in Hegel’s terms of the infinite right of the subject to satisfy himself in his activity and work; because of that, this, sixth Neo is new. After showing the differences in the objectives of Neo and Agent Smith, and transformations of the objectives of humans, the third part of the article analyzes the very end of the Matrix Revolutions, using Marx’s ideas, with some references to Plato and Nietzsche.
Expel poetry from life and society, exile poets. Modern interpretations of the Platonic postulate
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Krystyna Bartol
2012-01-01
Full Text Available This article is a critical review of the most important modern interpretations of the Platonic postulate of expelling poets from the polis, formulated in two works of the thinker, the Republic and the Laws. The reflections presented in the article focus on two fundamental questions, namely the reasons behind Plato’s refusal to allow poets into his ideal state and, secondly, the aim he was going to attain by expelling artists from the community of citizens. To try to explain the reasons behind these statements, so embarrassing to present-day readers of Plato, involves considerations of Plato’s concept of the nature of poetry (art as flawed, defective and secondary reflection of the sensual world, as well as of ethical questions (art as a perfidious tool to facilitate malevolent designs towards human characters. Any investigation as to the intentions of the philosophers that preceded the formulation of the postulate concentrates thus inevitably on his vision of utopian realism. It further aims to provide sufficient arguments that Plato, oscillating in his presentation between authoritarian diagnosis and protreptic provocation, makes recipients redefine the mutual relationship between literature and philosophy.
Une histoire de la lumière de Platon au photon
Maitte, Bernard
2015-01-01
De la sensation commune à la compréhension scientifique, nos idées sur la nature et les propriétés de la lumière ont connu un long cheminement depuis les théories de Platon jusqu'à la maîtrise du photon. L'Antiquité, la civilisation arabo-islamique, la Renaissance européenne et sa révolution scientifique, puis la science classique du me siècle, les avancées modernes enfin, autant de moments dans la riche histoire de nos connaissances sur la lumière. Ce livre décrit l'élaboration tourmentée des idées, tant philosophiques que scientifiques, qui ont scandé cette histoire, tirant profit des succès comme des échecs, des efforts comme des renoncements. "En regardant d'un oeil critique l'histoire de la lumière, nous pourrons accéder à notre tour à cette logique savoureuse et amère que l'on appelle Science." La première édition de ce livre, ici considérablement augmentée, a obtenu le prix Jean-Rostand du meilleur ouvrage de vulgarisation scientifique.
Ultra-large supramolecular coordination cages composed of endohedral Archimedean and Platonic bodies
Byrne, Kevin; Zubair, Muhammad; Zhu, Nianyong; Zhou, Xiao-Ping; Fox, Daniel S.; Zhang, Hongzhou; Twamley, Brendan; Lennox, Matthew J.; Düren, Tina; Schmitt, Wolfgang
2017-05-01
Pioneered by Lehn, Cram, Peterson and Breslow, supramolecular chemistry concepts have evolved providing fundamental knowledge of the relationships between the structures and reactivities of organized molecules. A particular fascinating class of metallo-supramolecular molecules are hollow coordination cages that provide cavities of molecular dimensions promoting applications in diverse areas including catalysis, enzyme mimetics and material science. Here we report the synthesis of coordination cages with exceptional cross-sectional diameters that are composed of multiple sub-cages providing numerous distinctive binding sites through labile coordination solvent molecules. The building principles, involving Archimedean and Platonic bodies, renders these supramolecular keplerates as a class of cages whose composition and topological aspects compare to characteristics of edge-transitive {Cu2} MOFs with A3X4 stoichiometry. The nature of the cavities in these double-shell metal-organic polyhedra and their inner/outer binding sites provide perspectives for post-synthetic functionalizations, separations and catalysis. Transmission electron microscopy studies demonstrate that single molecules are experimentally accessible.
Ponderomotive light squeezing with atomic cavity optomechanics
Brooks, Daniel W C; Brahms, Nathan; Purdy, Thomas P; Schreppler, Sydney; Stamper-Kurn, Dan M
2011-01-01
Accessing distinctly quantum aspects of the interaction between light and the position of a mechanical object has been an outstanding challenge to cavity-optomechanical systems. Only cold-atom implementations of cavity optomechanics have indicated effects of the quantum fluctuations in the optical radiation pressure force. Here we use such a system, in which quantum photon-number fluctuations significantly drive the center of mass of an atomic ensemble inside a Fabry-Perot cavity. We show that the optomechanical response both amplifies and ponderomotively squeezes the quantum light field. We also demonstrate that classical optical fluctuations can be attenuated by 26 dB or amplified by 20 dB with a weak input pump power of < 40 pW, and characterize the optomechanical amplifier's frequency-dependent gain and phase response in both the amplitude and phase-modulation quadratures.
Experimental generation of amplitude squeezed vector beams
Chille, Vanessa; Semmler, Marion; Banzer, Peter; Aiello, Andrea; Leuchs, Gerd; Marquardt, Christoph
2016-01-01
We present an experimental method for the generation of amplitude squeezed high-order vector beams. The light is modified twice by a spatial light modulator such that the vector beam is created by means of a collinear interferometric technique. A major advantage of this approach is that it avoids systematic losses, which are detrimental as they cause decoherence in continuous-variable quantum systems. The utilisation of a spatial light modulator (SLM) gives the flexibility to switch between arbitrary mode orders. The conversion efficiency with our setup is only limited by the efficiency of the SLM. We show the experimental generation of Laguerre-Gauss (LG) modes with radial indices up to 1 and azimuthal indices up to 3 with complex polarization structures and a quantum noise reduction up to -0.9dB$\\pm$0.1dB. The corresponding polarization structures are studied in detail by measuring the spatial distribution of the Stokes parameters.
Science, society, and the coastal groundwater squeeze
Michael, Holly A.; Post, Vincent E. A.; Wilson, Alicia M.; Werner, Adrian D.
2017-04-01
Coastal zones encompass the complex interface between land and sea. Understanding how water and solutes move within and across this interface is essential for managing resources for society. The increasingly dense human occupation of coastal zones disrupts natural groundwater flow patterns and degrades freshwater resources by both overuse and pollution. This pressure results in a "coastal groundwater squeeze," where the thin veneers of potable freshwater are threatened by contaminant sources at the land surface and saline groundwater at depth. Scientific advances in the field of coastal hydrogeology have enabled responsible management of water resources and protection of important ecosystems. To address the problems of the future, we must continue to make scientific advances, and groundwater hydrology needs to be firmly embedded in integrated coastal zone management. This will require interdisciplinary scientific collaboration, open communication between scientists and the public, and strong partnerships with policymakers.
EDITORIAL: Squeeze transformation and optics after Einstein
Kim, Young S.; Man'ko, Margarita A.; Planat, Michel
2005-12-01
With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besançon, France, 2-6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458-S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo
论英国文艺复兴时期的新柏拉图主义图景%Neo-Platonic Variations in Renaissance England
Institute of Scientific and Technical Information of China (English)
潘先利
2012-01-01
Neo-Platonic variations in Renaissance England is a promising arena for further scholarly exploration. A platonic landscape is outlined with explicit British features： John Colet＇s idea in Christian image, Thomas Moore＇s Platonic Utopian train of thought and John Dee＇s Christian-Platonic numerology and magic--all construct a blueprint of Platonic cosmos.%英国文艺复兴时期的新柏拉图主义在当时是一股不可忽略的知性力量，但其形成性研究还是一个学术冷门。主要考证该思潮的本土化变体，尤其聚焦约翰·克里特的基督教理式模型、托马斯·莫尔结合了柏拉图古典社会完美观念和古罗马修辞策略的鸟托邦思想、约翰·迪的基督教一柏拉图式数字命理哲学和神秘主义魔法理论等具有英国风貌的新柏拉图主义宇宙图景。
CALL FOR PAPERS: Optics and squeeze transformations after Einstein
Kim, Young S.; Man'ko, Margarita A.; Planat, Michel
2005-01-01
Journal of Optics B: Quantum and Semiclassical Optics will publish a special issue in connection with the 9th International Conference on Squeezed States and Uncertainty Relations, to be held in Besançon, France, on 2-6 May 2005. In 2005, the physics community celebrates the 100th anniversary of the publication of Einstein’s theories of relativity and quantum physics. To celebrate these great contributions to physics, the conference will include sessions on Einstein’s influence on modern optics and the foundations of quantum mechanics. Conference participants, as well as other researchers working in the field, are invited to submit research papers to this special issue of the journal. The topics to be covered include: • Superposition principle • Squeezed states • Uncertainty relations • Quantum state generation and characterization • Phase space and group representations in quantum physics • Quantum transforms in signal analysis • Information theory and quantum computing • Quantum interference, decoherence and entanglement measure • Quantum chaos and quantum control • Bell inequalities • Nonstationary Casimir effect • Quantum-like and mesoscopic systems Manuscripts should be submitted by 1 August 2005 as the special issue is scheduled for publication in March 2006. All papers will be peer reviewed and the normal refereeing standards of Journal of Optics B: Quantum and Semiclassical Optics will be maintained. The Editorial Division of IOP Publishing at the P N Lebedev Physical Institute in Moscow will oversee editorial procedures in association with the IOP Publishing office in Bristol. There are no page charges for publication. Submissions should preferably be in either standard LaTeX form or Microsoft Word. Advice on publishing your work in the journal, including specific information on figures, tables and references, may be found at www.iop.org/journals/authors. Manuscripts should be submitted by e-mail to the Guest Editors at IOPP
Two-dimensional atom localization induced by a squeezed vacuum
Wang, Fei; Xu, Jun
2016-10-01
A scheme of two-dimensional (2D) atom localization induced by a squeezed vacuum is proposed, in which the three-level V-type atoms interact with two classical standing-wave fields. It is found that when the environment is changed from an ordinary vacuum to a squeezed vacuum, the 2D atom localization is realized by detecting the position-dependent resonance fluorescence spectrum. For comparison, we demonstrate that the atom localization originating from the quantum interference effect is distinct from that induced by a squeezed vacuum. Furthermore, the combined effects of the squeezed vacuum and quantum interference are also discussed under appropriate conditions. The internal physical mechanism is analyzed in terms of dressed-state representation. Project supported by the National Natural Science Foundation of China (Grant Nos. 11574179 and 11204099) and the Natural Science Foundation of Hubei Province, China (Grant No. 2014CFC1148).
MRE properties under shear and squeeze modes and applications
Energy Technology Data Exchange (ETDEWEB)
Popp, K M [TU Bergakademie Freiberg, Institute of Machine Elements, Design and Production, Agricolastrasse 1, 09599 Freiberg (Germany); Zhang, X Z; Li, W H; Kosasih, P B [University of Wollongong, School of Mechanical, Materials and Mechatronic Engineering, NSW 2522 (Australia)], E-mail: Kristin.Popp@imkf.tu-freiberg.de, E-mail: weihuali@uow.edu.au
2009-02-01
Magnetorheological elastomers (MREs) belong to the group of so called smart materials. Due to an applied magnetic field the MREs change their material properties like the stiffness. This feature has resulted in a number of novel applications, such as adaptive tuned dynamic vibration absorbers (ATDVA) for suppressing unwanted vibrations over a wide frequency range. MRE based devices operate in different modes, such as shear mode and squeeze mode but the study of mechanical performances of MREs under squeeze mode is very rare. This paper aims to investigate MRE performances under both shear and squeeze modes. Both experimental and simulation studies were conducted to analyze the MR effect in both modes. These studies indicate that MRE working in squeeze mode would result in higher MR effects. As a case study, a MRE based ATDVA was analyzed, which demonstrated good capabilities in reducing vibrations.
Squeezed Phonons: Modulating Quantum Fluctuations of Atomic Displacements.
Hu, Xuedong; Nori, Franco
1997-03-01
We have studied phonon squeezed states and also put forward several proposals for their generation(On phonon parametric process, X. Hu and F. Nori, Phys. Rev. Lett. 76), 2294 (1996); on polariton mechanism, X. Hu and F. Nori, Phys. Rev. B 53, 2419 (1996); on second-order Raman scattering, X. Hu and F. Nori, preprint.. Here, we compare the relative merits and limitations of these approaches, including several factors that will limit the amount of phonon squeezing. In particular, we investigate the effect of the initial thermal states on the phonon modes. Using a model for the phonon density matrix, we also study the mixing of the phonon squeezed states with thermal states, which describes the decay of the phonon coherence. Finally, we calculate the maximum possible squeezing from a phonon parametric process limited by phonon decay.
An integrated source of broadband quadrature squeezed light
Hoff, Ulrich B; Andersen, Ulrik L
2015-01-01
An integrated silicon nitride resonator is proposed as an ultra-compact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing the device. An asymmetric double layer stack waveguide geometry with inverse vertical tapers is proposed for efficient and robust fibre-chip coupling, yielding a simulated total loss of -0.75 dB/facet. We assess the feasibility of the device through a full quantum noise analysis and derive the output squeezing spectrum for intra-cavity pump self-phase modulation. Subject to standard material loss and detection efficiencies, we find that the device holds promises for generating substantial quantum noise squeezing over a bandwidth exceeding 1 GHz. In the low-propagation loss regime, approximately -7 dB squeezing is predicted for a pump power of only 50 mW.
Squeezed light from second-harmonic generation: experiment versus theory.
Ralph, T C; Taubman, M S; White, A G; McClelland, D E; Bachor, H A
1995-06-01
We report excellent quantitative agreement between theoretical predictions and experimental observation of squeezing from a singly resonant second-harmonic-generating crystal. Limitations in the noise suppression imposed by the pump laser are explicitly modeled and confirmed by our measurements.
Resonance Fluorescence from an Artificial Atom in Squeezed Vacuum
National Research Council Canada - National Science Library
Toyli, D. M; Eddins, A. W; Boutin, S; Puri, S; Hover, D; Bolkhovsky, V; Oliver, W. D; Blais, A; Siddiqi, I
2016-01-01
.... We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier...
Fifth International Conference on Squeezed States and Uncertainty Relations
Han, D. (Editor); Janszky, J. (Editor); Kim, Y. S. (Editor); Man'ko, V. I. (Editor)
1998-01-01
The Fifth International Conference on Squeezed States and Uncertainty Relations was held at Balatonfured, Hungary, on 27-31 May 1997. This series was initiated in 1991 at the College Park Campus of the University of Maryland as the Workshop on Squeezed States and Uncertainty Relations. The scientific purpose of this series was to discuss squeezed states of light, but in recent years the scope is becoming broad enough to include studies of uncertainty relations and squeeze transformations in all branches of physics including quantum optics and foundations of quantum mechanics. Quantum optics will continue playing the pivotal role in the future, but the future meetings will include all branches of physics where squeeze transformations are basic. As the meeting attracted more participants and started covering more diversified subjects, the fourth meeting was called an international conference. The Fourth International Conference on Squeezed States and Uncertainty Relations was held in 1995 was hosted by Shanxi University in Taiyuan, China. The fifth meeting of this series, which was held at Balatonfured, Hungary, was also supported by the IUPAP. In 1999, the Sixth International Conference will be hosted by the University of Naples in 1999. The meeting will take place in Ravello near Naples.
Application Of CFD To Modeling Of Squeeze Mode Magnetorheological Dampers
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Gołdasz Janusz
2015-09-01
Full Text Available The so-called squeeze flow involves a magnetorheological (MR fluid sandwiched between two planar surfaces setting up a flow channel. The height of the channel varies according to a prescribed displacement or force profile. When exposed to a magnetic field of sufficient strength MR fluids develop a yield stress. In squeeze-mode devices the yield stress varies with both the magnetic field magnitude and the channel height. In this paper an unsteady flow model of an MR fluid in squeeze mode is proposed. The model is developed in Ansys Fluent R16. The MR material flow model is based on the apparent viscosity approach. In order to investigate the material's behaviour the authors prepared a model of an idealized squeeze-mode damper in which the fluid flow is enforced by varying the height of the channel. Using mesh animation, the model plate is excited, and as the mesh moves, the fluid is squeezed out of the gap. In the simulations the model is subjected to a range of displacement inputs of frequencies from 10 to 20 Hz, and local yield stress levels up to 30 kPa. The results are presented in the form of time histories of the normal force on the squeezing plate and loops of force vs. displacement (velocity.
Squeezing-out dynamics in free-standing smectic films
Energy Technology Data Exchange (ETDEWEB)
S̀liwa, Izabela, E-mail: izasliwa@ifmpan.poznan.pl [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznaǹ (Poland); Vakulenko, A.A. [Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178 (Russian Federation); Zakharov, A.V., E-mail: alexandre.zakharov@yahoo.ca [Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178 (Russian Federation)
2016-05-06
Highlights: • We model the dynamics of layer transitions. • We model the thermally activated nucleation of a small hole. • We model the dynamics of squeezing-out one layer. - Abstract: We have carried out a theoretical study of the dynamics of the squeezing-out of one layer from the N-layer free-standing smectic film (FSSF) coupled with a meniscus, during the layer-thinning process. Squeezing-out is initiated by a thermally activated nucleation process in which a density fluctuation forms a small void in the center of the circular FSSF. The pressure gradient develops between the squeezed-out and nonsqueezed-out areas and is responsible for the driving out of one or several layer(s) from the N-layer smectic film. The dynamics of the boundary between these areas in the FSSF is studied by the use of the conservation laws for mass and linear momentum with accounting for the coupling between the meniscus and the smectic film. This coupling has a strong effect on the dynamics of the squeezing-out process and may significantly change the time which is needed to completely squeezed-out one or several layer(s) from the N-layer smectic film.
Institute of Scientific and Technical Information of China (English)
HU Li-Yun; FAN Hong-Yi
2008-01-01
We find that the squeezed two-mode number state is just a two-variable Hermite polynomial excitation of the two-mode squeezed vacuum state (THPES). We find that the Wigner function of THPES and its marginal distributions are just related to two-variable Hermite polynomials (or Laguerre polynomials) and that the tomogram of THPES can be expressed by one-mode Hermite polynomial.
Institute of Scientific and Technical Information of China (English)
王琳; 高敏娜
2014-01-01
The background of Captain Corelli’s Mandolin is based on World War II. When the war provoked on the Greek Is-land, the Greeks fight against the Italian Fascist and live a tough life with their love. This article mainly talks about the essence of the Platonic love revealed in the book. By analyzing the description about homosexuality and heterosexuality in the book, this ar-ticle acclaims the essence of the Platonic love-the noble abstention of lust-based love and the truth, kindness and beauty of love.
EDITORIAL: Squeezed states and uncertainty relations
Jauregue-Renaud, Rocio; Kim, Young S.; Man'ko, Margarita A.; Moya-Cessa, Hector
2004-06-01
This special issue of Journal of Optics B: Quantum and Semiclassical Optics is composed mainly of extended versions of talks and papers presented at the Eighth International Conference on Squeezed States and Uncertainty Relations held in Puebla, Mexico on 9-13 June 2003. The Conference was hosted by Instituto de Astrofísica, Óptica y Electrónica, and the Universidad Nacional Autónoma de México. This series of meetings began at the University of Maryland, College Park, USA, in March 1991. The second and third workshops were organized by the Lebedev Physical Institute in Moscow, Russia, in 1992 and by the University of Maryland Baltimore County, USA, in 1993, respectively. Afterwards, it was decided that the workshop series should be held every two years. Thus the fourth meeting took place at the University of Shanxi in China and was supported by the International Union of Pure and Applied Physics (IUPAP). The next three meetings in 1997, 1999 and 2001 were held in Lake Balatonfüred, Hungary, in Naples, Italy, and in Boston, USA, respectively. All of them were sponsored by IUPAP. The ninth workshop will take place in Besançon, France, in 2005. The conference has now become one of the major international meetings on quantum optics and the foundations of quantum mechanics, where most of the active research groups throughout the world present their new results. Accordingly this conference has been able to align itself to the current trend in quantum optics and quantum mechanics. The Puebla meeting covered most extensively the following areas: quantum measurements, quantum computing and information theory, trapped atoms and degenerate gases, and the generation and characterization of quantum states of light. The meeting also covered squeeze-like transformations in areas other than quantum optics, such as atomic physics, nuclear physics, statistical physics and relativity, as well as optical devices. There were many new participants at this meeting, particularly
Directory of Open Access Journals (Sweden)
Mauro Bonazzi
2013-05-01
Full Text Available The chapters dedicated to Parmenides and Plato play a decisive role in the composition strategy of the Adversus Colotem, since this is where Plutarch most clearly defines the background dualist thesis that will help demonstrate that Platonism is superior to Epicurism. By showing Parmenides too as a dualist engaged in distinguishing between the sensible and the intelligible world, Plutarch structures a history of ancient philosophy entirely focused on Plato. These chapters also bear witness of another centre of interest, namely Aristoteles (§ 14, who, despite the criticism he aimed at the theory of ideas, is not completely refuted, but rather used as a possible ally against epicurean materialists, Plutarch’s true bête noire.Les chapitres consacrés à Parménide et Platon jouent un rôle décisif dans la stratégie de composition de l’Adversus Colotem : c’est là en effet que Plutarque définit de la manière la plus claire la thèse dualiste de fond qui va servir à démontrer la supériorité du platonisme sur l’épicurisme. En présentant Parménide lui aussi comme un dualiste occupé à distinguer entre monde sensible et monde intelligible, Plutarque articule une histoire de la philosophie antique entièrement centrée sur Platon. Les chapitres témoignent ensuite d’un autre centre d’intérêt, avec la mention d’Aristote (§ 14, lequel, malgré les critiques qu’il adresse à la théorie des idées, n’est pas complètement réfuté, mais plutôt utilisé comme un allié possible contre les matérialistes épicuriens, la véritable « bête noire » de Plutarque.I capitoli dedicati a Parmenide e Platone giocano un ruolo decisivo nella strategia compositiva dell’Adversus Colotem: è qui infatti che Plutarco delinea nel modo più chiaro la tesi dualistica di fondo che servirà a dimostrare la superiorità del platonismo sull’epicureismo. Presentando anche Parmenide come un dualista, impegnato a distinguere tra mondo
Fourth International Conference on Squeezed States and Uncertainty Relations
Han, D. (Editor); Peng, Kunchi (Editor); Kim, Y. S. (Editor); Manko, V. I. (Editor)
1996-01-01
The fourth International Conference on Squeezed States and Uncertainty Relations was held at Shanxi University, Taiyuan, Shanxi, China, on June 5 - 9, 1995. This conference was jointly organized by Shanxi University, the University of Maryland (U.S.A.), and the Lebedev Physical Institute (Russia). The first meeting of this series was called the Workshop on Squeezed States and Uncertainty Relations, and was held in 1991 at College Park, Maryland. The second and third meetings in this series were hosted in 1992 by the Lebedev Institute in Moscow, and in 1993 by the University of Maryland Baltimore County, respectively. The scientific purpose of this series was initially to discuss squeezed states of light, but in recent years, the scope is becoming broad enough to include studies of uncertainty relations and squeeze transformations in all branches of physics, including, of course, quantum optics and foundations of quantum mechanics. Quantum optics will continue playing the pivotal role in the future, but the future meetings will include all branches of physics where squeeze transformations are basic transformation. This transition took place at the fourth meeting of this series held at Shanxi University in 1995. The fifth meeting in this series will be held in Budapest (Hungary) in 1997, and the principal organizer will be Jozsef Janszky of the Laboratory of Crystal Physics, P.O. Box 132, H-1052. Budapest, Hungary.
L’ORALITÀ A SCUOLA, DA PLATONE AL PORTFOLIO EUROPEO DELLE LINGUE
Directory of Open Access Journals (Sweden)
Alberto A. Sobrero
2010-09-01
Full Text Available L'oralità risulta primaria rispetto alla scrittura sia per quanto riguarda la razza umana (filogenesi sia per quanto riguarda lo sviluppo individuale (ontogenesi, tuttavia essa ha sempre goduto di minor prestigio della scrittura. Nella prima parte di questo articolo sono ricostruiti i diversi momenti in cui questa gerarchia è stata fondata e si è affermata stabilmente: dai contrasti epocali tra Socrate e Platone da una parte e i Sofisti dall'altra all'affermazione della centralità della scrittura da parte di Aristotele e degli aristotelici; fino, poi, all'Illuminismo, in cui l'oralità veniva ormai identificata con l'inciviltà, la rozzezza e l'arretratezza, posizione che in qualche misura permane ancora oggi. Nella seconda parte dell'articolo si ricostruisce il graduale recupero del valore dell'oralità nell'insegnamento linguistico, attraverso un'analisi dei programmi scolastici italiani, dalla Legge Casati del 1859 ai Programmi della scuola media e di quella elementare rispettivamente del 1979 e del 1985, alle più recenti "Indicazioni Moratti e infine alle "Indicazioni Fioroni". In queste ultime si sottolinea la necessità di finalizzare l'insegnamento dell'oralità anche a scopi interculturali più ampi, prioritari nella società attuale, quali il rispetto e la promozione delle differenze linguistiche e culturali, lo sviluppo del plurilinguismo; la centralità e l'autonomia dell'apprendente. Historically, the oral tradition has been more important than writing, both in human history (philogenesis and in individual, personal history (onthogenesis, but it has always had far less prestige. The first part of this paper surveys important moments in the formation and establishment of this hierarchy, starting from the fundamental contrast between the Sophists on the one hand, and Socrates and Plato from the other, to the centrality of Aristotle and Aristotelianism, up to the Age of Enlightenment and the identification between orality
Minimum Uncertainty, Coherence and Squeezing in Diffusion Processes, and Stochastic Quantization
De Martino, S; Illuminati, F; Vitiello, G; Martino, Salvatore De; Siena, Silvio De; Illuminati, Fabrizio; Vitiello, Giuseppe
1993-01-01
We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.
Entropy Squeezing in Coupled Field-Superconducting Charge Qubit with Intrinsic Decoherence
Institute of Scientific and Technical Information of China (English)
YAN Xue-Qun; SHAO Bin; ZOU Jian
2007-01-01
We investigate the entropy squeezing in the system of a superconducting charge qubit coupled to a single mode field. We find an exact solution of the Milburn equation for the system and discuss the influence of intrinsic decoherence on entropy squeezing. As a comparison, we also consider the variance squeezing. Our results show that in the absence of the intrinsic decoherence both entropy and variance squeezings have the same periodic properties of time,and occur at the same range of time. However, when the intrinsic decoherence is considered, we find that as the time going on the entropy squeezing disappears fast than the variance squeezing, there exists a range of time where entropy squeezing can occur but variance squeezing cannot.
Information Entropy. and Squeezing of Quantum Fluctuations in a Two-Level Atom
Institute of Scientific and Technical Information of China (English)
FANG Mao-Fa; ZHOU Peng; S. Swain
2000-01-01
We study the atomic squeezing in the language of the quantum information theory. A rigorous entropy uncertainty relation which suits for characterizing the squeezing of a two-level atoms is obtained, and a general definition of information entropy squeezing in the two-level atoms is given. The information entropy squeezing of two-level atoms interacting with a single-mode quantum field is examined. Our results show that the information entropy is a superior measure of the quantum uncertainty of atomic observable, also is a remarkable good precision measure of atomic squeezing. When the population difference of two-level atom is zero, the definition of atomic squeezing based on the Heisenberg uncertainty relation is trivial, while the definition of information entropy squeezing of the atom based on the entropy uncertainty relation is valid and can provide full information on the atomic squeezing in any cases.
Entanglement and extreme spin squeezing of unpolarized states
Vitagliano, Giuseppe; Apellaniz, Iagoba; Kleinmann, Matthias; Lücke, Bernd; Klempt, Carsten; Tóth, Géza
2017-01-01
We present criteria to detect the depth of entanglement in macroscopic ensembles of spin-j particles using the variance and second moments of the collective spin components. The class of states detected goes beyond traditional spin-squeezed states by including Dicke states and other unpolarized states. The criteria derived are easy to evaluate numerically even for systems of very many particles and outperform past approaches, especially in practical situations where noise is present. We also derive analytic lower bounds based on the linearization of our criteria, which make it possible to define spin-squeezing parameters for Dicke states. In addition, we obtain spin squeezing parameters also from the condition derived in (Sørensen and Mølmer 2001 Phys. Rev. Lett. 86 4431). We also extend our results to systems with fluctuating number of particles.
Squeezing of X waves with orbital angular momentum
Ornigotti, Marco; Szameit, Alexander; Conti, Claudio
2016-01-01
Multi-level quantum protocols may potentially supersede standard quantum optical polarization-encoded protocols in terms of amount of information transmission and security. However, for free space telecomunications, we do not have tools for limiting loss due to diffraction and perturbations, as for example turbulence in air. Here we study propagation invariant quantum X-waves with angular momentum; this representation expresses the electromagnetic field as a quantum gas of weakly interacting bosons. The resulting spatio-temporal quantized light pulses are not subject to diffraction and dispersion, and are intrinsically resilient to disturbances in propagation. We show that spontaneous down-conversion generates squeezed X-waves useful for quantum protocols. Surprisingly the orbital angural momentum affects the squeezing angle, and we predict the existence of a characteristic axicon aperture for maximal squeezing. There results may boost the applications in free space of quantum optical transmission and multi-l...
High-rate squeezing process of bulk metallic glasses
Fan, Jitang
2017-03-01
High-rate squeezing process of bulk metallic glasses from a cylinder into an intact sheet achieved by impact loading is investigated. Such a large deformation is caused by plastic flow, accompanied with geometrical confinement, shear banding/slipping, thermo softening, melting and joining. Temperature rise during the high-rate squeezing process makes a main effect. The inherent mechanisms are illustrated. Like high-pressure torsion (HPT), equal channel angular pressing (ECAP) and surface mechanical attrition treatments (SMAT) for refining grain of metals, High-Rate Squeezing (HRS), as a multiple-functions technique, not only creates a new road of processing metallic glasses and other metallic alloys for developing advanced materials, but also directs a novel technology of processing, grain refining, coating, welding and so on for treating materials.
Squeezing of light via reflection from a silicon micromechanical resonator
Safavi-Naeini, Amir H; Hill, Jeff T; Chan, Jasper; Aspelmeyer, Markus; Painter, Oskar
2013-01-01
We present the measurement of squeezed light generation using an engineered optomechanical system fabricated from a silicon microchip and composed of a micromechanical resonator coupled to a nanophotonic cavity. Laser light is used to measure the fluctuations in the position of the mechanical resonator at a measurement rate comparable to the free dynamics of the mechanical resonator, and greater than its thermal decoherence rate. By approaching the strong continuous measurement regime we observe, through homodyne detection, non-trivial modifications of the reflected light's vacuum fluctuation spectrum. In spite of the mechanical resonator's highly excited thermal state ($10,000$ phonons), we observe squeezing at the level of $4.5 \\pm 0.5%$ below that of shot-noise over a few MHz bandwidth around the mechanical resonance frequency of 28 MHz. This squeezing is interpreted as an unambiguous quantum signature of radiation pressure shot-noise.
Effects of reservoir squeezing on quantum systems and work extraction
Huang, X. L.; Wang, Tao; Yi, X. X.
2012-11-01
We establish a quantum Otto engine cycle in which the working substance contacts with squeezed reservoirs during the two quantum isochoric processes. We consider two working substances: (1) a qubit and (2) two coupled qubits. Due to the effects of squeezing, the working substance can be heated to a higher effective temperature, which leads to many interesting features different from the ordinary ones, such as (1) for the qubit as working substance, if we choose the squeezed parameters properly, the positive work can be exported even when TH
Effect of squeeze on electrostatic Trivelpiece-Gould wave damping
Energy Technology Data Exchange (ETDEWEB)
Ashourvan, Arash; Dubin, Daniel H. E. [Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)
2014-05-15
We present a theory for increased damping of Trivelpiece-Gouid plasma modes on a nonneutral plasma column, due to application of a Debye shielded cylindrically symmetric squeeze potential φ{sub 1}. We present two models of the effect this has on the plasma modes: a 1D model with only axial dependence, and a 2D model that also keeps radial dependence in the squeezed equilibrium and the mode. We study the models using both analytical and numerical methods. For our analytical studies, we assume that φ{sub 1}/T≪1, and we treat the Debye shielded squeeze potential as a perturbation in the equilibrium Hamiltonian. Our numerical simulations solve the 1D Vlasov-Poisson system and obtain the frequency and damping rate for a self-consistent plasma mode, making no assumptions as to the size of the squeeze. In both the 1D and 2D models, damping of the mode is caused by Landau resonances at energies E{sub n} for which the particle bounce frequency ω{sub b}(E{sub n}) and the wave frequency ω satisfy ω=nω{sub b}(E{sub n}). Particles experience a non-sinusoidal wave potential along their bounce orbits due to the squeeze potential. As a result, the squeeze induces bounce harmonics with n > 1 in the perturbed distribution. The harmonics allow resonances at energies E{sub n}≤T that cause substantial damping, even when wave phase velocities are much larger than the thermal velocity. In the regime ω/k≫√(T/m) (k is the wave number) and T≫φ{sub 1}, the resonance damping rate has a |φ{sub 1}|{sup 2} dependence. This dependence agrees with the simulations and experimental results.
Which Q-analogue of the squeezed oscillator?
Solomon, Allan I.
1993-01-01
The noise (variance squared) of a component of the electromagnetic field - considered as a quantum oscillator - in the vacuum is equal to one half, in appropriate units (taking Planck's constant and the mass and frequency of the oscillator all equal to 1). A practical definition of a squeezed state is one for which the noise is less than the vacuum value - and the amount of squeezing is determined by the appropriate ratio. Thus the usual coherent (Glauber) states are not squeezed, as they produce the same variance as the vacuum. However, it is not difficult to define states analogous to coherent states which do have this noise-reducing effect. In fact, they are coherent states in the more general group sense but with respect to groups other than the Heisenberg-Weyl Group which defines the Glauber states. The original, conventional squeezed state in quantum optics is that associated with the group SU(1,1). Just as the annihilation operator a of a single photon mode (and its hermitian conjugate a, the creation operator) generates the Heisenberg Weyl algebra, so the pair-photon operator a(sup 2) and its conjugate generates the algebra of the group SU(1,1). Another viewpoint, more productive from the calculational stance, is to note that the automorphism group of the Heisenberg-Weyl algebra is SU(1,1). Needless to say, each of these viewpoints generalizes differently to the quantum group context. Both are discussed. The following topics are addressed: conventional coherent and squeezed states; eigenstate definitions; exponential definitions; algebra (group) definitions; automorphism group definition; example: signal-to-noise ratio; q-coherent and q-squeezed states; M and P q-bosons; eigenstate definitions; exponential definitions; algebra (q-group) definitions; and automorphism q-group definition.
A faster urethral pressure reflectometry technique for evaluating the squeezing function
DEFF Research Database (Denmark)
Klarskov, Niels; Saaby, Marie-Louise; Lose, Gunnar
2013-01-01
Abstract Objective. Urethral pressure reflectometry (UPR) has shown to be superior in evaluating the squeeze function compared to urethral pressure profilometry. The conventional UPR measurement (step method) required up to 15 squeezes to provide one measure of the squeezing opening pressure and ...
Stefszky, Michael; Mow-Lowry, Conor M.; McKenzie, Kirk; Chua, Sheon; Buchler, Ben C.; Symul, Thomas; McClelland, David E.; Lam, Ping Koy
2011-01-01
A squeezed light source requires properties such as high squeezing amplitude, high bandwidth and stability over time, ideally using as few resources, such as laser power, as possible. We compare three nonlinear materials, two of which have not been well characterized for squeezed state production,
Stefszky, Michael; Mow-Lowry, Conor M.; McKenzie, Kirk; Chua, Sheon; Buchler, Ben C.; Symul, Thomas; McClelland, David E.; Lam, Ping Koy
2011-01-01
A squeezed light source requires properties such as high squeezing amplitude, high bandwidth and stability over time, ideally using as few resources, such as laser power, as possible. We compare three nonlinear materials, two of which have not been well characterized for squeezed state production, a
Metal-matrix interpenetrating phasecomposites produced by squeeze casting
Institute of Scientific and Technical Information of China (English)
沈彬; 胡文彬; 刘磊; 周伟; 张荻
2002-01-01
On the basis of the proposition and manufacture of a new type of metal-matrix interpenetrating phase composites (MMIPCs) by vacuum high-pressure infiltration, squeeze casting method was chosen for further study on this new type of MMIPCs. By employing the highly porous ceramic perform made from SHS reaction of Al-TiO2-C system, squeeze casting process was studied in detail. By means of OM, SEM and TEM, the obtained highly porous SHS reaction products and the resulting MMIPCs for further understanding were closely examined and analyzed.
Squeeze-Out of Branched Alkanes on Graphite
Gosvami, N. N.; Sinha, S. K.; O'Shea, S. J.
2008-02-01
We study squalane and heptamethylnonane (HMN) confined between a conducting atomic force microscope tip and a graphite surface. Solvation layering occurs for both liquids but marked differences in the squeeze out mechanics are observed for ordered or disordered monolayers. The squalane monolayer at 25°C is an ordered solid, as verified by direct imaging, and the squeeze out can be modeled using elastic continuum mechanics. HMN is in a disordered state at 25°C and cannot be modeled as a single elastic asperity even in solid-solid contact because HMN liquid is trapped in the contact zone.
Coupling Measurements and Corrections for the Combined Ramp and Squeeze
Persson, Tobias Hakan Bjorn; Langner, Andy Sven; Malina, Lukas; Maclean, Ewen Hamish; Coello De Portugal - Martinez Vazquez, Jaime Maria; Redaelli, Stefano; Salvachua Ferrando, Belen Maria; Schaumann, Michaela; Solfaroli Camillocci, Matteo; Skowronski, Piotr Krzysztof; Tomas Garcia, Rogelio; Garcia-Tabares Valdivieso, Ana; Wenninger, Jorg; CERN. Geneva. ATS Department
2016-01-01
In operation of the LHC the ramp and the squeeze process have been independent beam processes up to now. Making them into a combined process would save time to reach the point where the beams are brought to collision. This would increase the integrated luminosity provided by the LHC. One possible source of problems could be deviation from the ideal optics and in particular the control of the transverse coupling. In this report we focus on the coupling measurements that were taken during the Combined Ramp and Squeeze (CRS) MD.
Improvement of an Atomic Clock using Squeezed Vacuum
DEFF Research Database (Denmark)
Kruse, I.; Lange, K; Peise, Jan
2016-01-01
Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case......, the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0...
Vibratile Coherence and Squeezing in Two Trapped Ions
Institute of Scientific and Technical Information of China (English)
ZENG HaoSheng; KUANG LeMan; ZHU XiWen; GAO KeLin
2002-01-01
It is shown that two trapped ions interacting with laser beams resonant to the first red side-band of center-of-mass mode, in Lamb Dicke regime and under rotating wave approximation, is described by a Jaynes-Cummingsmodel. For the initial condition that the motional state of center-of-mass mode is in vacuum state and the internal stateis prepared in a coherent superposition of states, coherence and squeezing for the vibratile motion of center-of-mass modeare discussed, particularly, a "weak" coherent state and a "weak" squeezed vacuum state are obtained. Collapse andrevival are also observed in this type of initial condition.
Classical Simulation of Squeezed Vacuum in Optical Waveguide Arrays
Sukhorukov, Andrey A; Sipe, John
2013-01-01
We reveal that classical light diffraction in arrays of specially modulated coupled optical waveguides can simulate the quantum process of two-mode squeezing in nonlinear media, with the waveguide mode amplitudes corresponding the signal and idler photon numbers. The whole Fock space is mapped by a set of arrays, where each array represents the states with a fixed difference between the signal and idler photon numbers. We demonstrate a critical transition from photon number growth to Bloch oscillations with periodical revivals of an arbitrary input state, associated with an increase of the effective phase mismatch between the pump and the squeezed photons.
Broadband detection of squeezed vacuum A spectrum of quantum states
Breitenbach, G; Schiller, S; Mlynek, J; Breitenbach, Gerd; Illuminati, Fabrizio; Schiller, Stephan; Mlynek, Jurgen
1998-01-01
We demonstrate the simultaneous quantum state reconstruction of the spectral modes of the light field emitted by a continuous wave degenerate optical parametric amplifier. The scheme is based on broadband measurement of the quantum fluctuations of the electric field quadratures and subsequent Fourier decomposition into spectral intervals. Applying the standard reconstruction algorithms to each bandwidth-limited quantum trajectory, a "spectrum" of density matrices and Wigner functions is obtained. The recorded states show a smooth transition from the squeezed vacuum to a vacuum state. In the time domain we evaluated the first order correlation function of the squeezed output field, showing good agreement with the theory.
Enforcing Margin Squeeze Ex Post Across Converging Telecommunications Markets
DEFF Research Database (Denmark)
Bergqvist, Christian; Townsend, John
A margin squeeze is an exclusionary abuse which occurs when a vertically Integrated telecoms operator creates a disparity between upstream and downstream prices with the intention of squeezing an access competitor’s profits. The purpose of such pricing is either to increase the latter’s entry costs...... and innovation present both theoretical and practical difficulties for assessing “muddled margins” on telecoms markets. New and different enforcement approaches to exclusion will have to be formulated within the Article 102 framework and tested in the Courts. This may even require abstaining from applying...
Displacement of microwave squeezed states with Josephson parametric amplifiers
Energy Technology Data Exchange (ETDEWEB)
Zhong, Ling; Baust, Alexander; Xie, Edwar; Schwarz, Manuel; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Fedorov, Kirill; Menzel, Edwin; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Betzenbichler, Martin; Pogorzalek, Stefan; Haeberlein, Max; Eder, Peter; Goetz, Jan; Wulschner, Karl Friedrich; Huebl, Hans; Deppe, Frank [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany)
2015-07-01
Propagating quantum microwaves are promising building blocks for quantum communication. Interestingly, such itinerant quantum microwaves can be generated in the form of squeezed photon states by Josephson parametric amplifiers (JPA). We employ a specific ''dual-path'' setup for both state reconstruction and JPA characterization. Displacement operations are performed by using a directional coupler after the squeezing. We compare our results with theory predictions. In particular, we discuss our experiments in the context of remote state preparation and quantum teleportation with propagating microwaves.
Bregestovski, Piotr
2012-01-01
On May 10th 2010 Platon Grigorevitch Kostyuk sadly left us at the age of 85. He was a talented scientist, a brilliant experimenter, an outstanding organizer of science and an excellent teacher. Platon Kostyuk was born in 1924 in Kiev, Ukraine. He obtained a double education: a graduate of the Kiev University Department of Biology in 1946 and the Kiev Medical Institute in 1949, he became a pioneer in neuroscience, the first in the Soviet Union to use microelectrodes for intracellular recording of electrical signals in neurons. Despite the difficulties for international travel for those living behind the Iron Curtain, he was able to present his work at the International Congress of Physiology in Buenos Aires in 1959 and here met Prof. John Eccles who invited him to work at the University of Canberra in Australia in 1960–1961. This was the start of an outstanding international career, complementing his creative achievements in the Soviet Union. In 1966 P.G. Kostyuk became director of the Bogomoletz Institute of Physiology in Kiev, which he headed for nearly 45 years. Under his direction this Institute became a leading centre for neuroscience, renowned not only in the Soviet Union but also internationally. New directions of research were developed in cell physiology, molecular biophysics and neurophysiology. Several important discoveries were made including the development of a method for intracellular perfusion, evidence for a calcium-dependent conductance in nerve cells and the discovery of new types of ion channels. Elected to the Ukraine Academy of Science in 1969 and Grand Academician of the Soviet Academy of Science in 1974, Kostyuk has also been honoured by many international societies. He is the author of more than 650 articles, 17 monographs and 7 discoveries and was the creator and editor of two scientific journals: "Neurophysiology" and "Neuroscience". The outstanding career and multifaceted activities of Academician Platon Kostyuk form a pyramid of
Quantum Nondemolition Measurement of a Quantum Squeezed State Beyond the 3 dB Limit
Lei, C. U.; Weinstein, A. J.; Suh, J.; Wollman, E. E.; Kronwald, A.; Marquardt, F.; Clerk, A. A.; Schwab, K. C.
2016-09-01
We use a reservoir engineering technique based on two-tone driving to generate and stabilize a quantum squeezed state of a micron-scale mechanical oscillator in a microwave optomechanical system. Using an independent backaction-evading measurement to directly quantify the squeezing, we observe 4.7 ±0.9 dB of squeezing below the zero-point level surpassing the 3 dB limit of standard parametric squeezing techniques. Our measurements also reveal evidence for an additional mechanical parametric effect. The interplay between this effect and the optomechanical interaction enhances the amount of squeezing obtained in the experiment.
An Analysis of the Agency and Providence in Platonic, Aristotelian and Avicennan Metaphysics
Directory of Open Access Journals (Sweden)
S. Mahdi Emamijomeh
2014-01-01
Full Text Available The questions as to whether the cosmic order of this world is based on action/agent or not? And if an agent is involved and the world and what it contains have to be seen as action, could we declare the cosmic order a providential order? are among the problems which have always occupied the mind of philosophers. Reading through Platonic corpse leads us to the conclusion that he has founded his metaphysics upon the very idea of world of ideas. According to his works and words, Plato is a proponent of the theory of ideas. As a matter of fact, Plato's metaphysics lies in the theory of ideas. Plato illustrates the general makeup of the world of ideas and the way sensible objects stand in relation with the beings dwelling in the latter world by the well-known cave allegory in the seventh book of Republic. In his view, whatever we find around ourselves not only are not authentic realities but rather they are merely shadows of the truth. Every phenomenon has an essence or reality which is known as its form. The idea of Good overshadows the other ideas insofar as these latter ideas or forms are seen as the effects of the former. It seems we can take God, the One, Absolute Good, Absolute Beauty and Good in itself as expressions of the same reality which Plato has used in different contexts through his works. Along these terms some other notions have also been brought up like intellect, divine intellect, Demiurge, ideas and the particulars of material world. By explaining Plato's taking of these notions and terms, we believe, one can discover Platonic ontological system. In Republic, Plato argues that God is the creator of ideal bed and all other things, and he is the creator of intelligible entities (ideas. The One or reality as a whole not only contains ideas but the spirit too. The One is the final principle and the source of ideas and is beyond all human attributes. Having said these, it is not clear how reason gets itself related to the
An Analysis of the Agency and Providence in Platonic, Aristotelian and Avicennan Metaphysics
Directory of Open Access Journals (Sweden)
Vahideh Hadad
2013-12-01
Full Text Available The questions as to whether the cosmic order of this world is based on action/agent or not? And if an agent is involved and the world and what it contains have to be seen as action, could we declare the cosmic order a providential order? are among the problems which have always occupied the mind of philosophers. Reading through Platonic corpse leads us to the conclusion that he has founded his metaphysics upon the very idea of world of ideas. According to his works and words, Plato is a proponent of the theory of ideas. As a matter of fact, Plato's metaphysics lies in the theory of ideas. Plato illustrates the general makeup of the world of ideas and the way sensible objects stand in relation with the beings dwelling in the latter world by the well-known cave allegory in the seventh book of Republic. In his view, whatever we find around ourselves not only are not authentic realities but rather they are merely shadows of the truth. Every phenomenon has an essence or reality which is known as its form. The idea of Good overshadows the other ideas insofar as these latter ideas or forms are seen as the effects of the former. It seems we can take God, the One, Absolute Good, Absolute Beauty and Good in itself as expressions of the same reality which Plato has used in different contexts through his works. Along these terms some other notions have also been brought up like intellect, divine intellect, Demiurge, ideas and the particulars of material world. By explaining Plato's taking of these notions and terms, we believe, one can discover Platonic ontological system. In Republic, Plato argues that God is the creator of ideal bed and all other things, and he is the creator of intelligible entities (ideas. The One or reality as a whole not only contains ideas but the spirit too. The One is the final principle and the source of ideas and is beyond all human attributes. Having said these, it is not clear how reason gets itself related to the
Scoping study on coastal squeeze in the Ayeyarwady Delta
Kroon, M.E.N.; Rutten, M.M.; Stive, M.J.F.; Wunna, S.
2015-01-01
Coastal squeeze is the reduction in the space of coastal habitats to operate (Phan et al, 2014) and an important cause for coastline retreat, increase in flood risk, salinity intrusion etc. Land use changes, such as deforestation and urbanization, reduce the space of natural habitats, such as mangro
Why the Marriage Squeeze Cannot Cause Dowry Inflation
Anderson, K.S.
2000-01-01
It has been argued that rising dowry payments are caused by population growth.According to that explanation, termed the `marriage squeeze', a population increase leads to an excess supply of brides since men marry younger women.As a result, dowry payments rise in order to clear the marriage market.T
Spin squeezing and light entanglement in Coherent Population Trapping
DEFF Research Database (Denmark)
Dantan, Aurelien Romain; Cviklinski, Jean; Giacobino, Elisabeth;
2006-01-01
We show that strong squeezing and entanglement can be generated at the output of a cavity containing atoms interacting with two fields in a coherent population trapping situation, on account of a nonlinear Faraday effect experienced by the fields close to a dark-state resonance in a cavity...
Squeezed State Effects on Continuous Variable Quantum Erasing
Bonanno, Peter; Kasisomayajula, Vijay; Russo, Onofrio
2008-03-01
Experimental verification of complementarity using quantum erasing for the continuous variable (CV) infinite dimensional Hilbert space has been considered. [1] The complemetary pair is that of the canonically conjugate amplitude and phase quadratures of light. The amplitude quadrature is labeled to a squeezed meter signal by quantum nondemolition (QND) [2] entanglement coupling. [3] Knowledge of which eigenstate (WE) can be obtained by measuring this amplitude in the meter state, and can thereafter be `lost' by measuring the quadrature phase of the meter, thus restoring the quadrature phase of the signal beam in a process known as quantum erasure. [4] The coupling, i.e. the labeling of the signal state to the meter state, is implemented with a beam splitter coupled to the squeezed light meter beam. [4] We investigate the effects of using the unitary squeeze operator S(z)=exp.5ex1 -.1em/ -.15em.25ex2 (z*a^2 - za^+2) where z = re^i(squeezing angle) on selected coherent states under certain conditions. [5,6] [1] U. L. Anderson et al., Phys. Rev. Lett. 93, 100403 (2004). [2] V. B. Braginsky et al., Science 209, 547 (1980). [3] R. Bruckmeimer et al., Phys. Rev. Lett. 79, 43 (1997). [4] P. Grangier et al., Nature 396, 537 (1998). [5] C. M. Caves, Phys. Rev. D 23, 1693 (1981). [6] D. Stoler, Phys. Rev. D. 1, 3217 (1970), D. Stoler, Phys. Rev. D. 4, 1925 (1971). .
Squeezing and entangling nuclear spins in helium 3
DEFF Research Database (Denmark)
Reinaudi, Gael; Sinatra, Alice; Dantan, Aurelien Romain
2007-01-01
We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of 3He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study t...
Scoping study on coastal squeeze in the Ayeyarwady Delta
Kroon, M.E.N.; Rutten, M.M.; Stive, M.J.F.; Wunna, S.
2015-01-01
Coastal squeeze is the reduction in the space of coastal habitats to operate (Phan et al, 2014) and an important cause for coastline retreat, increase in flood risk, salinity intrusion etc. Land use changes, such as deforestation and urbanization, reduce the space of natural habitats, such as mangro
Wormholes and negative energy from the gravitationally squeezed vacuum
Hochberg, David
1992-01-01
Minkowski-signature wormhole solutions of the Einstein field equations require the existence of negative energy density in the vicinity of their throats. We point out that the gravitational interaction automatically generates squeezed vacuum states of matter, which by their nature, entail negative energy and, thus, provide a natural source for maintaining this class of wormholes.
Lorentz Harmonics, Squeeze Harmonics and Their Physical Applications
Directory of Open Access Journals (Sweden)
Marilyn E. Noz
2011-02-01
Full Text Available Among the symmetries in physics, the rotation symmetry is most familiar to us. It is known that the spherical harmonics serve useful purposes when the world is rotated. Squeeze transformations are also becoming more prominent in physics, particularly in optical sciences and in high-energy physics. As can be seen from Dirac’s light-cone coordinate system, Lorentz boosts are squeeze transformations. Thus the squeeze transformation is one of the fundamental transformations in Einstein’s Lorentz-covariant world. It is possible to define a complete set of orthonormal functions defined for one Lorentz frame. It is shown that the same set can be used for other Lorentz frames. Transformation properties are discussed. Physical applications are discussed in both optics and high-energy physics. It is shown that the Lorentz harmonics provide the mathematical basis for squeezed states of light. It is shown also that the same set of harmonics can be used for understanding Lorentz-boosted hadrons in high-energy physics. It is thus possible to transmit physics from one branch of physics to the other branch using the mathematical basis common to them.
Four modes of optical parametric operation for squeezed state generation
DEFF Research Database (Denmark)
Andersen, Ulrik Lund; Buchler, B.C.; Lam, P.K.;
2003-01-01
of this light, including a full quantum state tomography. In addition we demonstrate the direct detection of the squeezed state statistics without the aid of a spectrum analyser. This technique makes the nonclassical properties directly visible and allows complete measurement of the statistical moments...
Gaussian private quantum channel with squeezed coherent states
Jeong, Kabgyun; Kim, Jaewan; Lee, Su-Yong
2015-01-01
While the objective of conventional quantum key distribution (QKD) is to secretly generate and share the classical bits concealed in the form of maximally mixed quantum states, that of private quantum channel (PQC) is to secretly transmit individual quantum states concealed in the form of maximally mixed states using shared one-time pad and it is called Gaussian private quantum channel (GPQC) when the scheme is in the regime of continuous variables. We propose a GPQC enhanced with squeezed coherent states (GPQCwSC), which is a generalization of GPQC with coherent states only (GPQCo) [Phys. Rev. A 72, 042313 (2005)]. We show that GPQCwSC beats the GPQCo for the upper bound on accessible information. As a subsidiary example, it is shown that the squeezed states take an advantage over the coherent states against a beam splitting attack in a continuous variable QKD. It is also shown that a squeezing operation can be approximated as a superposition of two different displacement operations in the small squeezing regime. PMID:26364893
Quantum reconstruction of an intense polarization squeezed optical state
DEFF Research Database (Denmark)
Marquardt, Ch.; Heersink, J.; Dong, R.
2007-01-01
We perform a reconstruction of the polarization sector of the density matrix of an intense polarization squeezed beam starting from a complete set of Stokes measurements. By using an appropriate quasidistribution, we map this onto the Poincare space, providing a full quantum mechanical...... characterization of the measured polarization state....
Instantaneous, non-squeezed, noise-based logic
Peper, Ferdinand
2010-01-01
Noise-based logic, by utilizing its multidimensional logic hyperspace, has significant potential for low-power parallel operations in beyond-Moore-chips. However universal gates for Boolean logic thus far had to rely on either time averaging to distinguish signals from each other or, alternatively, on squeezed logic signals, where the logic-high was represented by a random process and the logic-low was a zero signal. A major setback is that squeezed logic variables are unable to work in the hyperspace, because the logic-low zero value sets the hyperspace product vector to zero. This paper proposes Boolean universal logic gates that alleviate such shortcomings. They are able to work with non-squeezed logic values where both the high and low values are encoded into nonzero, bipolar, independent random telegraph waves. Non-squeezed universal Boolean logic gates for spike-based brain logic are also shown. The advantages vs. disadvantages of the two logic types are compared.
Squeezing-enhanced measurement sensitivity in a cavity optomechanical system
DEFF Research Database (Denmark)
Kerdoncuff, Hugo; Hoff, Ulrich Busk; Harris, Glen I.;
2015-01-01
We determine the theoretical limits to squeezing-enhanced measurement sensitivity of mechanical motion in a cavity optomechanical system. The motion of a mechanical resonator is transduced onto quadrature fluctuations of a cavity optical field and a measurement is performed on the optical field e...
Dynamical squeezing enhancement in the off-resonant Dicke model
Energy Technology Data Exchange (ETDEWEB)
Shindo, D; Chavez, A; Chumakov, S M; Klimov, A B [Departamento de FIsica, Universidad de Guadalajara, Revolucion 1500, 44420, Guadalajara, Jalisco (Mexico)
2004-01-01
We show that the maximum atomic squeezing that can be achieved in the vacuum off-resonant Dicke model (governed by the effective Hamiltonian {approx} S{sub z}{sup 2}) can be essentially enhanced by applying a sequence of {pi}/2 pulses at certain time moments. The major effect is obtained after the first pulse.
Holographic Description of Negative Null Energy in Squeezed Vacuum States
Lee, Da-Shin
2016-01-01
Using the AdS/CFT duality, we study the expectation value of stress tensor in squeezed vacuum states of $2+1$-dimensional quantum critical theories with a general dynamical scaling $z$. The holographic dual theory is the theory of gravity in 3+1-dimensional Lifshitz backgrounds. We then adopt a consistent approach to obtain the boundary stress tensor from bulk construction, which satisfies the trace Ward identity associated with Lifshitz scaling symmetry. The scheme for holographic dual of squeezed vacuum states is found to be the gravity theory in the geometry perturbed by gravitational wave. For small squeezing parameters, the expectation value of stress tensor in squeezed vacuum states is obtained for both strongly coupled quantum critical fields and free relativistic fields. We find that, in both cases with $z=1$, the stress tensor satisfies the averaged null energy condition and is consistent with the quantum interest conjecture. In particular, the negative lower bound on null-contracted stress tensor, w...
Globalisation squeezes the public sector - is it so obvious?
DEFF Research Database (Denmark)
Andersen, Torben M.; Sørensen, Allan
It is widely perceived that globalization squeezes public sector activities by making taxation more costly. This is attributed to increased factor mobility and to a more elastic labour demand due to improved scope for relocation of production and thus employment across countries. We argue...
Quantum correlations induced by multiple scattering of quadrature squeezed light
DEFF Research Database (Denmark)
Lodahl, Peter
2006-01-01
Propagating quadrature squeezed light through a multiple scattering random medium is found to induce pronounced spatial quantum correlations that have no classical analogue. The correlations are revealed in the number of photons transported through the sample that can be measured from the intensity...
Polarization squeezing and entanglement produced by a frequency doubler
DEFF Research Database (Denmark)
Andersen, Ulrik Lund; Buchhave, Preben
2003-01-01
The quantum mechanical polarization properties of a nondegenerate second harmonic generator, where a nonlinear type II crystal is placed inside a cavity, are investigated theoretically. We demonstrate the possibility of strong squeezing of the continuous Stokes parameters as well as strong entang...... entanglement between them....
Squeezing of thermal and quantum fluctuations: Universal features
DEFF Research Database (Denmark)
Svensmark, Henrik; Flensberg, Karsten
1993-01-01
We study the classical and quantum fluctuations of a general damped forced oscillator close to a bifurcation instability. Near the instability point, the fluctuations are strongly phase correlated and are squeezed. In the limit of low damping, it is shown that the system has universal features wh...
Demonstration of deterministic and high fidelity squeezing of quantum information
DEFF Research Database (Denmark)
Yoshikawa, J-I.; Hayashi, T-; Akiyama, T.
2007-01-01
By employing a recent proposal [R. Filip, P. Marek, and U.L. Andersen, Phys. Rev. A 71, 042308 (2005)] we experimentally demonstrate a universal, deterministic, and high-fidelity squeezing transformation of an optical field. It relies only on linear optics, homodyne detection, feedforward, and an...
Denton, Michael J; Marshall, Craig J; Legge, Michael
2002-12-07
Before the Darwinian revolution many biologists considered organic forms to be determined by natural law like atoms or crystals and therefore necessary, intrinsic and immutable features of the world order, which will occur throughout the cosmos wherever there is life. The search for the natural determinants of organic form-the celebrated "Laws of Form"-was seen as one of the major tasks of biology. After Darwin, this Platonic conception of form was abandoned and natural selection, not natural law, was increasingly seen to be the main, if not the exclusive, determinant of organic form. However, in the case of one class of very important organic forms-the basic protein folds-advances in protein chemistry since the early 1970s have revealed that they represent a finite set of natural forms, determined by a number of generative constructional rules, like those which govern the formation of atoms or crystals, in which functional adaptations are clearly secondary modifications of primary "givens of physics." The folds are evidently determined by natural law, not natural selection, and are "lawful forms" in the Platonic and pre-Darwinian sense of the word, which are bound to occur everywhere in the universe where the same 20 amino acids are used for their construction. We argue that this is a major discovery which has many important implications regarding the origin of proteins, the origin of life and the fundamental nature of organic form. We speculate that it is unlikely that the folds will prove to be the only case in nature where a set of complex organic forms is determined by natural law, and suggest that natural law may have played a far greater role in the origin and evolution of life than is currently assumed.
Information Entropy Squeezing for a Atom in Mode-Mode Competition System
Institute of Scientific and Technical Information of China (English)
WU Qin; FANG Mao-Fa; LI Shao-Xin; LI Ying; HU Yao-Hua
2008-01-01
The entropy squeezing properties for a two-level atom interacting with a two-mode field via two different competing transitions are investigated from a quantum information point of view. The influences of the initial state of the system and the relative coupling strength between the atom and the field on the atomic information entropy squeezing are discussed. Our results show that the squeezed direction and the frequency of the information entropy squeezing can be controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field, respectively. We find that, under the same condition, no atomic variance squeezing is predicted from the HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information entropy is a remarkable precision measure for the atomic squeezing in the considered system.
Generation of continuous-wave and pulsed squeezed light with $^{87}$Rb vapor
Agha, Imad H; Grangier, Philippe
2009-01-01
We present experimental studies on the generation of squeezed vacuum via nonlinear ellipse rotation in a $^{87}$Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum squeezing observed is -1.4 $\\pm$0.1 dB (-2.0 dB corrected for loss). We measure -1.1 dB squeezing at the resonance frequency of the $^{85}$Rb $F=2 \\to F'=3$ transition, which may allow the storage of squeezed light generated by $^{87}$Rb in a $^{85}$Rb quantum memory. We also demonstrate a proof of principle pulsed squeezed light experiment, with -1 dB of squeezing for 200 ns pulse width.
Generation of pulsed and continuous-wave squeezed light with 87Rb vapor.
Agha, Imad H; Messin, Gaétan; Grangier, Philippe
2010-03-01
We present experimental studies on the generation of pulsed and continuous-wave squeezed vacuum via nonlinear rotation of the polarization ellipse in a (87)Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum continuous-wave squeezing observed is -1.4 +/- 0.1 dB (-2.0 dB corrected for losses). We measure -1.1 dB squeezing at the resonance frequency of the (85)Rb F = 3 --> F' transition, which may allow the storage of squeezed light generated by (87)Rb in a (85)Rb quantum memory. Using a pulsed pump, pulsed squeezed light with -1 dB of squeezing for 200 ns pulse widths is observed at 1 MHz repetition rate.
Institute of Scientific and Technical Information of China (English)
李春先; 方卯发; 等
2003-01-01
We study the squeezing for a two-level atom in the Jaynes-Cumings model with intensity-dependent coupling using quantum information entropy,and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing.Our results show that,the squeezed component number depends on the atomic initial distribution angle,while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing.Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.
Institute of Scientific and Technical Information of China (English)
李春先; 方卯发
2003-01-01
We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.
Squeezing Alters Frequency Tuning of WGM Optical Resonator
Mohageg, Makan; Maleki, Lute
2010-01-01
Mechanical squeezing has been found to alter the frequency tuning of a whispering-gallery-mode (WGM) optical resonator that has an elliptical shape and is made of lithium niobate. It may be possible to exploit this effect to design reconfigurable optical filters for optical communications and for scientific experiments involving quantum electrodynamics. Some background information is prerequisite to a meaningful description of the squeezing-induced alteration of frequency tuning: The spectrum of a WGM resonator is represented by a comblike plot of intensity versus frequency. Each peak of the comblike plot corresponds to an electromagnetic mode represented by an integer mode number, and the modes are grouped into sets represented by integer mode indices. Because lithium niobate is an electro-optically active material, the WGM resonator can be tuned (that is, the resonance frequencies can be shifted) by applying a suitable bias potential. The frequency shift of each mode is quantified by a tuning rate defined as the ratio between the frequency shift and the applied potential. In the absence of squeezing, all modes exhibit the same tuning rate. This concludes the background information. It has been demonstrated experimentally that when the resonator is squeezed along part of either of its two principal axes, tuning rates differ among the groups of modes represented by different indices (see figure). The differences in tuning rates could be utilized to configure the resonance spectrum to obtain a desired effect; for example, through a combination of squeezing and electrical biasing, two resonances represented by different mode indices could be set at a specified frequency difference something that could not be done through electrical biasing alone.
Optimization of Squeeze Casting for Aluminum Alloy Parts
Energy Technology Data Exchange (ETDEWEB)
David Schwam; John F. Wallace; Qingming Chang; Yulong Zhu
2002-07-30
This study was initiated with the installation of a new production size UBE 350 Ton VSC Squeeze Casting system in the Metal Casting Laboratory at Case Western University. A Lindberg 75k W electrical melting furnace was installed alongside. The challenge of installation and operation of such industrial-size equipment in an academic environment was met successfully. Subsequently, a Sterling oil die heater and a Visi-Track shot monitoring system were added. A significant number of inserts were designed and fabricated over the span of the project, primarily for squeeze casting different configurations of test bars and plates. A spiral ''ribbon insert'' for evaluation of molten metal fluidity was also fabricated. These inserts were used to generate a broad range of processing conditions and determine their effect on the quality of the squeeze cast parts. This investigation has studied the influence of the various casting variables on the quality of indirect squeeze castings primarily of aluminum alloys. The variables studied include gating design, fill time and fill patter, metal pressure and die temperature variations. The quality of the die casting was assessed by an analysis of both their surface condition and internal soundness. The primary metal tested was an aluminum 356 alloy. In addition to determining the effect of these casting variables on casting quality as measured by a flat plate die of various thickness, a number of test bar inserts with different gating designs have been inserted in the squeeze casting machine. The mechanical properties of these test bars produced under different squeeze casting conditions were measured and reported. The investigation of the resulting properties also included an analysis of the microstructure of the squeeze castings and the effect of the various structural constituents on the resulting properties. The main conclusions from this investigation are as follows: The ingate size and shape are very important
L’anagogie poétique. Un dialogue entre Virgile et Platon
Directory of Open Access Journals (Sweden)
Jelena Pilipović
2010-02-01
Full Text Available Établir des relations constructives entre la poésie de Virgile et certains aspects de la pensée platonicienne constitue le but de notre recherche, dont le texte présenté ici propose une esquisse. Cette recherche n’est fondée ni sur la notion d’influence ni sur celle d’analogie – la première exigeant une approche historique et biographique, la deuxième présupposant un parallélisme entre les deux œuvres antiques –, mais sur la notion de participation constructive. La notion pivot qui permet de défendre cette idée est le concept d’anagogie. L’anagogie ou l’ascension, décrite dans les textes originaux de Platon d’une manière plutôt poétique que théorétique (Phèdre, Symposion, sera incorporée dans le système philosophique de l’époque médioplatonicienne (Didaskalos d’Alkinoos : étant établi le télos suprême de l’existence humaine, elle représente la pénétration de l’âme dans le domaine éïdétique surpassant le monde sensible. Reflétée dans la structure autant que dans le corpus thématique de l’œuvre virgilienne, l’anagogie peut être proclamée comme l’un de ses principes créatifs. Sur le plan structural, la poétique de polysémie et l’idéal des significations cachées forment une hiérarchie sémantique, grâce à laquelle l’acte de lire devient une sorte d’ascension à travers le texte. La forme polysémique graduelle du texte virgilien est le fruit et l’objet central de cet article.The aim of this paper is to establish constructive relations between Virgilian poetry and some aspects of Plato’s thought. The research is based neither on the notion of influence, demanding a historical-biographical approach, nor on the notion of analogy, the two opera not being equal and their relation being causality instead of similarity, but on the notion of constructive participation. The key-point in defending this idea is, consequently, the concept of anagogy. Anagogy, or the
Principal Shapes and Squeezed Limits in the Effective Field Theory of Large Scale Structure
Bertolini, Daniele
2016-01-01
We apply an orthogonalization procedure on the effective field theory of large scale structure (EFT of LSS) shapes, relevant for the angle-averaged bispectrum and non-Gaussian covariance of the matter power spectrum at one loop. Assuming natural-sized EFT parameters, this identifies a linear combination of EFT shapes - referred to as the principal shape - that gives the dominant contribution for the whole kinematic plane, with subdominant combinations suppressed by a few orders of magnitude. For the covariance, our orthogonal transformation is in excellent agreement with a principal component analysis applied to available data. Additionally we find that, for both observables, the coefficients of the principal shapes are well approximated by the EFT coefficients appearing in the squeezed limit, and are thus measurable from power spectrum response functions. Employing data from N-body simulations for the growth-only response, we measure the single EFT coefficient describing the angle-averaged bispectrum with $\\...
Directory of Open Access Journals (Sweden)
FENG HE
2017-03-01
Full Text Available In this paper, an effective tool based on harmonic balance method to assess the forced response of these systems under parametric changes is developed. A flexible rotor with multiple masses supported on a squeeze film damper at one end is investigated and modeled using finite element method. The forced response of this asymmetrically supported system is calculated using the harmonic balance method with a predictor-corrector procedure by changing unidirectional loads, stiffness of centering spring of the damper and the gyroscopic effects of the disks. It is observed that under large unbalance forces, jump phenomenon occurs due to the nonlinear forces of SFD which indicates the presence of multiple harmonics within the response of the SFD operating at high eccentricity ratios and shows the insensitivity of the damper to surrounding gyroscopic variation.
Entanglement entropy of squeezed vacua on a lattice
Bianchi, Eugenio; Yokomizo, Nelson
2015-01-01
We derive a formula for the entanglement entropy of squeezed states on a lattice in terms of the complex structure J. The analysis involves the identification of squeezed states with group-theoretical coherent states of the symplectic group and the relation between the coset Sp(2N,R)/Isot(J_0) and the space of complex structures. We present two applications of the new formula: (i) we derive the area law for the ground state of a scalar field on a generic lattice in the limit of small speed of sound, (ii) we compute the rate of growth of the entanglement entropy in the presence of an instability and show that it is bounded from above by the Kolmogorov-Sinai rate.
The Achromatic Telescopic Squeezing (ATS) MD part II
Fartoukh, S; De Maria, R; Miyamoto, R; Mueller, G; Ponce, L; Redaelli, S; Strzelczyk, M; Tomas, R; Vanbavinckhove, G; Wenninger, J; Albert, M; Giachino, R; Giovannozzi, M; Goddard, B; Hagen, P; Hofle, W; Kain, V; Macpherson, A; Normann, L; Papotti, G; Steinhagen, R; Valuch, D; wollman, D
2011-01-01
This note describes the results obtained during the second so-called ATS MD where the record of Beta* was reached at IP1 and IP5 with a “pre-squeezed” Beta* of 1.2 m, while perfectly controlling the chromatic aberrations induced (non-linear chromaticity, off-momentum Beta-beating). Then, the ATLAS insertion was squeezed further down to the target of the former LHC Upgrade Project (Phase I), that is to Beta* = 30 cm, using the Achromatic Telescopic Squeezing techniques. In view of this major achievement, the bar is fixed even higher for the next ATS MD’s, with an ultimate Beta* targeted to 10 cm for the two high-luminosity insertions ATLAS and CMS.
Coherent quantum squeezing due to the phase space noncommutativity
Bernardini, Alex E
2015-01-01
The effect of phase space general noncommutativity on producing deformed coherent squeezed states is examined. A two-dimensional noncommutative quantum system supported by a deformed mathematical structure similar to that of Hadamard billiards is obtained and their components behavior are monitored in time. It is assumed that the independent degrees of freedom are two \\emph{free} 1D harmonic oscillators (HO's), so the system Hamiltonian does not contain interaction terms. Through the noncommutative deformation parameterized by a Seiberg-Witten transform on the original canonical variables, one gets the standard commutation relations for the new ones, such that the obtained Hamiltonian represents then two \\emph{interacting} 1D HO's. By assuming that one HO is inverted relatively to the other, we show that their effective interaction induces a squeezing dynamics for initial coherent states imaged in the phase space. A suitable pattern of logarithmic spirals is obtained and some relevant properties are discussed...
Improvement of an Atomic Clock using Squeezed Vacuum
DEFF Research Database (Denmark)
Kruse, I.; Lange, K; Peise, Jan;
2016-01-01
, the vacuum noise restricts the precision of the interferometer to the standard quantum limit (SQL). Here, we propose and experimentally demonstrate a novel clock configuration that surpasses the SQL by squeezing the vacuum in the empty input state. We create a squeezed vacuum state containing an average of 0.......75 atoms to improve the clock sensitivity of 10000 atoms by 2.05+0.34−0.37 dB. The SQL poses a significant limitation for today’s microwave fountain clocks, which serve as the main time reference. We evaluate the major technical limitations and challenges for devising a next generation of fountain clocks......Since the pioneering work of Ramsey, atom interferometers are employed for precision metrology, in particular to measure time and to realize the second. In a classical interferometer, an ensemble of atoms is prepared in one of the two input states, whereas the second one is left empty. In this case...
Vibratile Coherence and Squeezing in Two Trapped Ions
Institute of Scientific and Technical Information of China (English)
ZENGHao－Sheng; KUANGLe－Man; 等
2002-01-01
It is shown that two trapped ions interacting with laser beams resonant to the first red side-band of center-of-mass mode,in Lamb-Dicke regime and under rotating wave approximation,is described by a Jaynes-Cummings model.For the initial condition that the motional state of center-of-mass mode is in vacuum state and the internal state is prepared in a coherent superposition of states,coherence and squeezing for the vibratile motion of center-of-mass mode are discussed,particularly,a“weak” coherent state and a “weak” squeezed vacuum state are obtained.Collapse and revival are also observed in this type of initial condition.
Squeezing-enhanced feedback cooling of a microresonator
DEFF Research Database (Denmark)
Kerdoncuff, Hugo
Since its inception, quantum mechanics have not ceased to fascinate the scientific world, and especially the fundamental question about the famous Schrödinger's cat being alive or dead, or both, is still far from being answered. Although superposition states have been achieved with small particle...... microtoroids. Secondly we model the dielectric gradient force actuation scheme and investigate its capabilities in controlling the vibrations of a microtoroid acoustic mode....... such oscillators into their quantum ground state. In the present work we investigate a cold damping scheme relying on the ultra-sensitive measurement of mechanical displacements, provided by a cavity-enhanced optomechanical interaction with quadrature squeezed states of light, to control strong dielectric gradient...... forces actuating the motion of a toroidal microresonator within a feedback loop. We first determine theoretically the conditions and limits to squeezing-enhanced measurement sensitivity of mechanical motion in a cavity optomechanical system, and perform experimentally a proof-of-principle on our...
Deterministic Squeezed States with Joint Measurements and Feedback
Greve, Graham P.; Cox, Kevin C.; Wu, Baochen; Thompson, James K.
2016-05-01
Joint measurement of many qubits or atoms is a powerful way to create entanglement for precision measurement and quantum information science. However, the random quantum collapse resulting from the joint measurement also leads to randomness in which entangled state is created. We present an experiment in which we apply real-time feedback to eliminate the randomness generated during the joint measurement of 5 ×104 laser-cooled Rb atoms. The feedback effectively steers the quantum state to a desired squeezed state. After feedback, the final state achieves a directly observed phase resolution variance up to 7.4(6) dB below the standard quantum limit for unentangled atoms. The entanglement and improved measurement capability of these states can be realized without retaining knowledge of the joint measurement's outcome, possibly opening new applications for spin squeezed states generated via joint measurement.
Quadrature-dependent Bogoliubov transformations and multiphoton squeezed states
De Siena, S; Illuminati, F; Siena, Silvio De; Lisi, Antonio Di; Illuminati, Fabrizio
2001-01-01
We introduce a linear, canonical transformation of the fundamental single--mode field operators $a$ and $a^{\\dagger}$ that generalizes the linear Bogoliubov transformation familiar in the construction of the harmonic oscillator squeezed states. This generalization is obtained by adding to the linear transformation a nonlinear function of any of the fundamental quadrature operators $X_{1}$ and $X_{2}$, making the original Bogoliubov transformation quadrature--dependent. Remarkably, the conditions of canonicity do not impose any constraint on the form of the nonlinear function, and lead to a set of nontrivial algebraic relations between the $c$--number coefficients of the transformation. We examine in detail the structure and the properties of the new quantum states defined as eigenvectors of the transformed annihilation operator $b$. These eigenvectors define a class of multiphoton squeezed states. The structure of the uncertainty products and of the quasiprobability distributions in phase space shows that bes...
The Bose-Hubbard model with squeezed dissipation
Quijandría, Fernando; Naether, Uta; Porras, Diego; José García-Ripoll, Juan; Zueco, David
2015-03-01
The stationary properties of the Bose-Hubbard model under squeezed dissipation are investigated. The dissipative model does not possess a U(1) symmetry but conserves parity. We find that =0 always holds, so no symmetry breaking occurs. Without the onsite repulsion, the linear case is known to be critical. At the critical point the system freezes to an EPR state with infinite two mode entanglement. We show here that the correlations are rapidly destroyed whenever the repulsion is switched on. As we increase the latter, the system approaches a thermal state with an effective temperature defined in terms of the squeezing parameter in the dissipators. We characterize this transition by means of a Gutzwiller ansatz and the Gaussian Hartree-Fock-Bogoliubov approximation.
Squeeze behaviors of magnetic powders between two parallel plates
Chen, Kaikai; Tian, Yu; Shan, Lei; Zhang, Xiangjun; Meng, Yonggang
2014-10-01
The dynamic compressive and static normal stresses of magnetic powders (MPs) with the constant volume squeezed between two parallel plates were experimentally studied. The compressive stress increased in a power law as the gap distance decreased, with an exponent range of -0.73 (0.04 T) to -2.63 (0.77 T). The values of the scale factor to normalize the compressive curves were mainly dominated by the applied magnetic field. The compressive behavior of the MPs showed a less significant velocity effect and initial gap distance effect than those of the magnetorheological (MR) and electrorheological (ER) fluids because of the absence of a host liquid. The compressive stress was generated by the serious particle aggregation, which was induced by a magnetic field and friction during compression. This study is designed to further the understanding of the behavior of smart ER/MR materials and the application of MP actuators in squeeze mode.
The POLIS interferometer for ponderomotive squeezed light generation
Calloni, Enrico; Conte, Andrea; De Laurentis, Martina; Naticchioni, Luca; Puppo, Paola; Ricci, Fulvio
2016-07-01
POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.
QUANTUM MECHANICS. Quantum squeezing of motion in a mechanical resonator.
Wollman, E E; Lei, C U; Weinstein, A J; Suh, J; Kronwald, A; Marquardt, F; Clerk, A A; Schwab, K C
2015-08-28
According to quantum mechanics, a harmonic oscillator can never be completely at rest. Even in the ground state, its position will always have fluctuations, called the zero-point motion. Although the zero-point fluctuations are unavoidable, they can be manipulated. Using microwave frequency radiation pressure, we have manipulated the thermal fluctuations of a micrometer-scale mechanical resonator to produce a stationary quadrature-squeezed state with a minimum variance of 0.80 times that of the ground state. We also performed phase-sensitive, back-action evading measurements of a thermal state squeezed to 1.09 times the zero-point level. Our results are relevant to the quantum engineering of states of matter at large length scales, the study of decoherence of large quantum systems, and for the realization of ultrasensitive sensing of force and motion.
The POLIS interferometer for ponderomotive squeezed light generation
Energy Technology Data Exchange (ETDEWEB)
Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)
2016-07-11
POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.
Entanglement dynamics of bipartite system in squeezed vacuum reservoirs
Bougouffa, Smail
2010-01-01
Entanglement plays a crucial role in quantum information protocols, thus the dynamical behavior of entangled states is of a great importance. In this paper we suggest a useful scheme that permits a direct measure of entanglement in a two-qubit cavity system. It is realized in the cavity-QED technology utilizing atoms as fying qubits. To quantify entanglement we use the concurrence. We derive the conditions, which assure that the state remains entangled in spite of the interaction with the reservoir. The phenomenon of sudden death entanglement (ESD) in a bipartite system subjected to squeezed vacuum reservoir is examined. We show that the sudden death time of the entangled states depends on the initial preparation of the entangled state and the parameters of the squeezed vacuum reservoir.
Entanglement dynamics of a bipartite system in squeezed vacuum reservoirs
Energy Technology Data Exchange (ETDEWEB)
Bougouffa, Smail [Department of Physics, Faculty of Science, Taibah University, PO Box 30002, Madinah (Saudi Arabia); Hindi, Awatif, E-mail: sbougouffa@taibahu.edu.sa, E-mail: sbougouffa@hotmail.com [Physics Department, College of Science, PO Box 22452, King Saud University, Riyadh 11495 (Saudi Arabia)
2011-02-15
Entanglement plays a crucial role in quantum information protocols; thus the dynamical behavior of entangled states is of great importance. In this paper, we suggest a useful scheme that permits a direct measure of entanglement in a two-qubit cavity system. It is realized through cavity-QED technology utilizing atoms as flying qubits. To quantify entanglement we use the concurrence. We derive the conditions that ensure that the state remains entangled in spite of the interaction with the reservoir. The phenomenon of entanglement sudden death in a bipartite system subjected to a squeezed vacuum reservoir is examined. We show that the sudden death time of the entangled states depends on the initial preparation of the entangled state and the parameters of the squeezed vacuum reservoir.
Quantum memory for entangled two-mode squeezed states
Jensen, K; Krauter, H; Fernholz, T; Nielsen, B M; Serafini, A; Owari, M; Plenio, M B; Wolf, M M; Polzik, E S
2010-01-01
A quantum memory for light is a key element for the realization of future quantum information networks. Requirements for a good quantum memory are (i) versatility (allowing a wide range of inputs) and (ii) true quantum coherence (preserving quantum information). Here we demonstrate such a quantum memory for states possessing Einstein-Podolsky-Rosen (EPR) entanglement. These multi-photon states are two-mode squeezed by 6.0 dB with a variable orientation of squeezing and displaced by a few vacuum units. This range encompasses typical input alphabets for a continuous variable quantum information protocol. The memory consists of two cells, one for each mode, filled with cesium atoms at room temperature with a memory time of about 1msec. The preservation of quantum coherence is rigorously proven by showing that the experimental memory fidelity 0.52(2) significantly exceeds the benchmark of 0.45 for the best possible classical memory for a range of displacements.
Coherent states and squeezed states, supercoherent states and supersqueezed states
Nieto, Michael Martin
1992-01-01
This article reports on a program to obtain and understand coherent states for general systems. Most recently this has included supersymmetric systems. A byproduct of this work has been studies of squeezed and supersqueezed states. To obtain a physical understanding of these systems has always been a primary goal. In particular, in the work on supersymmetry an attempt to understand the role of Grassmann numbers in quantum mechanics has been initiated.
Third International Workshop on Squeezed States and Uncertainty Relations
Han, D. (Editor); Kim, Y. S. (Editor); Rubin, Morton H. (Editor); Shih, Yan-Hua (Editor); Zachary, Woodford W. (Editor)
1994-01-01
The purpose of these workshops is to bring together an international selection of scientists to discuss the latest developments in Squeezed States in various branches of physics, and in the understanding of the foundations of quantum mechanics. At the third workshop, special attention was given to the influence that quantum optics is having on our understanding of quantum measurement theory. The fourth meeting in this series will be held in the People's Republic of China.
Sixth International Conference on Squeezed States and Uncertainty Relations
Han, D. (Editor); Kim, Y. S. (Editor); Solimento, S. (Editor)
2000-01-01
These proceedings contain contributions from about 200 participants to the 6th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'99) held in Naples May 24-29, 1999, and organized jointly by the University of Naples "Federico II," the University of Maryland at College Park, and the Lebedev Institute, Moscow. This was the sixth of a series of very successful meetings started in 1990 at the College Park Campus of the University of Maryland. The other meetings in the series were held in Moscow (1992), Baltimore (1993), Taiyuan P.R.C. (1995) and Balatonfuered, Hungary (1997). The present one was held at the campus Monte Sant'Angelo of the University "Federico II" of Naples. The meeting sought to provide a forum for updating and reviewing a wide range of quantum optics disciplines, including device developments and applications, and related areas of quantum measurements and quantum noise. Over the years, the ICSSUR Conference evolved from a meeting on quantum measurement sector of quantum optics, to a wide range of quantum optics themes, including multifacet aspects of generation, measurement, and applications of nonclassical light (squeezed and Schrodinger cat radiation fields, etc.), and encompassing several related areas, ranging from quantum measurement to quantum noise. ICSSUR'99 brought together about 250 people active in the field of quantum optics, with special emphasis on nonclassical light sources and related areas. The Conference was organized in 8 Sections: Squeezed states and uncertainty relations; Harmonic oscillators and squeeze transformations; Methods of quantum interference and correlations; Quantum measurements; Generation and characterisation of non-classical light; Quantum noise; Quantum communication and information; and Quantum-like systems.
An Experimental Study on Steel and Teflon Squeeze Film Dampers
Directory of Open Access Journals (Sweden)
Asad A. Khalid
2006-01-01
Full Text Available In this paper, the vibration analysis on Teflon and steel squeeze film dampers has been carried out. At different frequency ranges, vibration amplitude and the resonance frequency are measured. The eccentricity ratio at resonance speed has been determined. Results show that the vibration amplitude of the steel damper is 10% less at resonance compared with the Teflon damper. On the other hand, saving weight of 36% has been achieved by using the Teflon damper.
Unconditional two-mode squeezing of separated atomic ensembles
Parkins, A S; Solano, E
2005-01-01
We propose schemes for the unconditional preparation of a two-mode squeezed state of effective bosonic modes realized in a pair of atomic ensembles interacting collectively with optical cavity and laser fields. The scheme uses Raman transitions between stable atomic ground states and under ideal conditions produces pure entangled states in the steady state. The scheme works both for ensembles confined within a single cavity and for ensembles confined in separate, cascaded cavities.
Roughness effect on squeeze ﬁlm pressure
Indian Academy of Sciences (India)
Manju Shukla
2002-10-01
The Stokes equations for the axial symmetric slow motion generated by a plane, approaching towards a solid surface allowing slippage, have been solved in this paper by using ﬁnite Hankel transform. The squeeze ﬁlm pressure between the two rigid faces is then obtained. It is found that the roughness parameter $\\beta \\sim d/4$, where is the separation between the two surfaces, causes an extremely high pressure on the surface.
beta* leveling with telescopic ATS squeeze (MD 2410)
Wenninger, Jorg; Hostettler, Michi; Pojer, Mirko; Ponce, Laurette; Tydecks, Tobias; CERN. Geneva. ATS Department
2017-01-01
Luminosity leveling by beta* is the baseline operational scenario of HL-LHC, and this leveling technique may be used in 2018 or during run~3 depending on the beam parameters and beta* range. During this MD beta*leveling was commissioned successfully for the first time with the telescopic squeeze over the beta* range of 40 cm to 30 cm. A novel beta* leveling controls technique based on a modification of the LSA trim was also tested during the MD.
Experimental demonstration of coherent feedback control on optical field squeezing
Iida, Sanae; Yonezawa, Hidehiro; Yamamoto, Naoki; Furusawa, Akira
2011-01-01
Coherent feedback is a non-measurement based, hence a back-action free, method of control for quantum systems. A typical application of this control scheme is squeezing enhancement, a purely non-classical effect in quantum optics. In this paper we report its first experimental demonstration that well agrees with the theory taking into account time delays and losses in the coherent feedback loop. The results clarify both the benefit and the limitation of coherent feedback control in a practical situation.
Noncritical quadrature squeezing through spontaneous polarization symmetry breaking
Garcia-Ferrer, Ferran V; de Valcárcel, Germán J; Roldán, Eugenio
2010-01-01
We discuss the possibility of generating noncritical quadrature squeezing by spontaneous polarization symmetry breaking. We consider first type-II frequency-degenerate optical parametric oscillators, but discard them for a number of reasons. Then we propose a four-wave mixing cavity in which the polarization of the output mode is always linear but has an arbitrary orientation. We show that in such a cavity complete noise suppression in a quadrature of the output field occurs, irrespective of the parameter values.
China's marriage squeeze: A decomposition into age and sex structure.
Jiang, Quanbao; Li, Xiaomin; Li, Shuzhuo; Feldman, Marcus W
2016-06-01
Most recent studies of marriage patterns in China have emphasized the male-biased sex ratio but have largely neglected age structure as a factor in China's male marriage squeeze. In this paper we develop an index we call "spousal sex ratio" (SSR) to measure the marriage squeeze, and a method of decomposing the proportion of male surplus into age and sex structure effects within a small spousal age difference interval. We project that China's marriage market will be confronted with a relatively severe male squeeze. For the decomposition of the cohort aged 30, from 2010 to 2020 age structure will be dominant, while from 2020 through 2034 the contribution of age structure will gradually decrease and that of sex structure will increase. From then on, sex structure will be dominant. The index and decomposition, concentrated on a specific female birth cohort, can distinguish spousal competition for single cohorts which may be covered by a summary index for the whole marriage market; these can also be used for consecutive cohorts to reflect the situation of the whole marriage market.
Analytical solutions for squeeze flow with partial wall slip
DEFF Research Database (Denmark)
Laun, HM; Rady, M; Hassager, Ole
1999-01-01
Squeeze flow between parallel plates of a purely viscous material is considered for small gaps both for a Newtonian and power law fluid with partial wall slip. The results for the squeeze force as a function of the squeezing speed reduce to the Stefan and Scott equations in the no slip limit......, respectively. The slip velocity at the plate increases linearly with the radius up to the rim slip velocity upsilon(s). For small Saps H, the resulting apparent Newtonian rim shear rate-measured for a constant rim shear stress, i.e. an imposed force increasing proportional to 1/H-yields a straight line...... if plotted versus 1/H. The slope of the straight line is equal to 6 upsilon(s) whereas the intersect with the ordinate yields the effective Newtonian rim shear rate to be converted into the true rim shear rate by means of the power law exponent. The advantage of the new technique is the separation of bulk...
Two-axis-twisting spin squeezing by multipass quantum erasure
Wang, Mingfeng; Qu, Weizhi; Li, Pengxiong; Bao, Han; Vuletić, Vladan; Xiao, Yanhong
2017-07-01
Many-body entangled states are key elements in quantum information science and quantum metrology. One important problem in establishing a high degree of many-body entanglement using optical techniques is the leakage of the system information via the light that creates such entanglement. We propose an all-optical interference-based approach to erase this information. Unwanted atom-light entanglement can be removed by destructive interference of three or more successive atom-light interactions, leaving behind only atom-atom entanglement. This quantum erasure protocol allows implementation of spin squeezing with Heisenberg scaling using coherent light and a cold or warm atomic ensemble. Calculations show that a significant improvement in the squeezing exceeding 10 dB is obtained compared to previous methods, and substantial spin squeezing is attainable even under moderate experimental conditions. Our method enables the efficient creation of many-body entangled states with simple setups and, thus, is promising for advancing technologies in quantum metrology and quantum information processing.
Squeezing of X waves with orbital angular momentum
Ornigotti, Marco; Villari, Leone Di Mauro; Szameit, Alexander; Conti, Claudio
2017-01-01
Multilevel quantum protocols may potentially supersede standard quantum optical polarization-encoded protocols in terms of amount of information transmission and security. However, for free-space telecommunications, we do not have tools for limiting loss due to diffraction and perturbations, as, for example, turbulence in air. Here we study propagation invariant quantum X waves with angular momentum; this representation expresses the electromagnetic field as a quantum gas of weakly interacting bosons. The resulting spatiotemporal quantized light pulses are not subject to diffraction and dispersion, and are intrinsically resilient to disturbances in propagation. We show that spontaneous down-conversion generates squeezed X waves useful for quantum protocols. Surprisingly, the orbital angular momentum affects the squeezing angle, and we predict the existence of a characteristic axicon aperture for maximal squeezing. These results may boost the applications in free space of quantum optical transmission and multilevel quantum protocols, and may also be relevant for novel kinds of interferometers, such as satellite-based gravitational wave detectors.
Single qubit operations with base squeezed coherent states
Podoshvedov, Sergey A.
2013-03-01
In quantum computing with base either coherent or squeezed coherent states, information is encoded into coherent states with opposite amplitudes. To exploit the base states in quantum computation, we need arbitrary qubit rotations plus a two-qubit gate such as controlled-Z gate to simulate any multiqubit unitary transformations. We develop an approach to realize single qubit operations with the base squeezed coherent states. The optical setup requires a resource of the base squeezed coherent states, unbalanced beam splitter whose transmittance tends to unity and photon counters in auxiliary modes. A successful two-photon subtraction from transmitted beam is heralded by two-photon click in auxiliary modes where tiny part of the initial beam is detected. The thrust of the method is that it achieves a high fidelity without photodetectors with a high efficiency or a single-photon resolution. We observe that there is wide diapason of values of the parameters that provide performance of single qubit operations with the base states. The problem is resolved in Wigner representation to take into account imperfections of the optical devices.
A squeezed light source operated under high vacuum
Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.
2015-01-01
Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments. PMID:26657616
Multipass configuration for improved squeezed vacuum generation in hot Rb vapor
Zhang, Mi; Guidry, Melissa A.; Lanning, R. Nicholas; Xiao, Zhihao; Dowling, Jonathan P.; Novikova, Irina; Mikhailov, Eugeniy E.
2017-07-01
We study a squeezed vacuum field generated in hot Rb vapor via the polarization self-rotation effect. Our previous experiments showed that the amount of observed squeezing may be limited by the contamination of the squeezed vacuum output with higher-order spatial modes, also generated inside the cell. Here, we demonstrate that the squeezing can be improved by making the light interact several times with a less dense atomic ensemble. With optimization of some parameters we can achieve up to -2.6 dB of squeezing in the multipass case, which is a 0.6 dB improvement compared to the single-pass experimental configuration. Our results show that, other than the optical depth of the medium, the spatial mode structure and the cell configuration also affect the squeezing level.
Effect of Squeezing on the Atomic and the Entanglement Dynamics in the Jaynes-Cummings Model
Subeesh, T; Ahmed, A B M; Satyanarayana, M Venkata
2012-01-01
The dynamics of the Jaynes-Cummings interaction of a two-level atom interacting with a single mode of the radiation field is investigated, as the state of the field is gradually changed from a coherent state to a squeezed coherent state. The effect of mild squeezing on the coherent light is shown to be striking: the photon number distribution gets localized and it peaks maximally for a particular value of squeezing. The atomic inversion retains its structure for a longer time. The mean linear entropy shows that the atom has a tendency to get disentangled from field within the collapse region and also in the revival region, for mild squeezing. These properties are absent for the case of a coherent state or for an excessively squeezed coherent state. We also elucidate a connection between these properties and the photon statistics of the mildly squeezed coherent state; these states have the minimum variance and are also maximally sub-Poissonian.
Information Entropy Squeezing of a Two-Level Atom Interacting with Two-Mode Coherent Fields
Institute of Scientific and Technical Information of China (English)
LIU Xiao-Juan; FANG Mao-Fa
2004-01-01
From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing.
Continuous-wave non-classical light with GHz squeezing bandwidth
Ast, Stefan; Mehmet, Moritz; Steinlechner, Sebastian; Eberle, Tobias; Schnabel, Roman
2012-01-01
Squeezed states can be employed for entanglement-based continuous-variable quantum key distribution, where the secure key rate is proportional to the bandwidth of the squeezing. We produced a non-classical continuous-wave laser field at the telecommunication wavelength of 1550 nm, which showed squeezing over a bandwidth of more than 2 GHz. The experimental setup used parametric down-conversion via a periodically poled potassium titanyl phosphate crystal (PPKTP). We did not use any resonant enhancement for the funda- mental wavelength, which should in principle allow a production of squeezed light over the full phase-matching bandwidth of several nanometers. We measured the squeezing to be up to 0.3 dB below the vacuum noise from 50 MHz to 2 GHz limited by the measuring bandwidth of the homodyne detector. The squeezing strength was possibly limited by thermal lensing inside the non-linear crystal.
Wudarski, Thomas J; Doty, Richard L
2004-02-01
Olfactory threshold measures are influenced by such factors as odorant species, diluent type, psychophysical paradigm, and stimulus-presentation procedure. In this study, we compared phenyl ethyl alcohol odor-detection thresholds obtained using 120-ml glass sniff bottles to those obtained using 120-ml plastic squeeze bottles. Although these presentation media are commonly employed in published studies, there has never been a formal comparison of values obtained using them. 10 male and 10 female subjects were tested on two threshold test sessions, one for each type of bottle. Order of sessions was systematically counterbalanced and completed on the same day for a given subject, with a minimum of 30 min. elapsing between sessions. A seven-reversal, single-staircase threshold procedure was employed. Although the threshold values were similar for the two procedures, slightly lower thresholds were obtained using the glass sniff bottles [respective M (SEM) log vol/vol values = -6.61 (.20) and -6.13 (.24)]. These data suggest that, while threshold values using these two presentation procedures can be roughly compared across studies, accurate comparisons may require a slight mathematical adjustment.
Spin Squeezing of Atomic Ensembles via Nuclear-Electronic Spin Entanglement
DEFF Research Database (Denmark)
Fernholz, Thomas; Krauter, Hanna; Jensen, K.
2008-01-01
We demonstrate spin squeezing in a room temperature ensemble of ≈1012 cesium atoms using their internal structure, where the necessary entanglement is created between nuclear and electronic spins of each individual atom. This state provides improvement in measurement sensitivity beyond the standard...... quantum limit for quantum memory experiments and applications in quantum metrology and is thus a complementary alternative to spin squeezing obtained via interatom entanglement. Squeezing of the collective spin is verified by quantum state tomography....
Spin Squeezing and Entanglement of Many-Particle Spin-Half States
Institute of Scientific and Technical Information of China (English)
YAN Dong; WANG Xiao-Guang; WU Ling-An
2005-01-01
@@ In many-particle spin-half systems with exchange symmetry, we find that the spin squeezing is related to two types of entanglement, the bipartite and the pairwise entanglement. A quantitative relationship is revealed for the spin squeezing parameter, the tangle, and the concurrence. We find that a class of states is spin squeezed if the pairwise entanglement is stronger than the bipartite entanglement.
Entanglement dynamics of non-interacting two-qubit system under a squeezed vacuum environment
Institute of Scientific and Technical Information of China (English)
Jun Qian; Xunli Feng; Shangqing Gong
2007-01-01
Entanglement dynamics of two non-interacting atoms in a squeezed vacuum reservoir is studied. Several examples with different initial entangled states are investigated, and it is found that entangled atoms become disentangled faster in squeezed vacuum than in ordinary vacuum, and larger squeezing results in faster entanglement decay. The time evolution of the concurrence and the separability "distance" A can be used to explain this novel entanglement sudden death phenomenon.
Preparation of Motional Mesoscopic Superpositions of Squeezed Coherent States of N Trapped Ions
Institute of Scientific and Technical Information of China (English)
YANG Wen-Xing; XIE Xiao-Tao; LI Jia-Hua; CHEN Chang-Yong
2005-01-01
A scheme is proposed to generate arbitrary, discrete superpostions of squeezed coherent states of the squeezed center of mass of N trapped ions along a straight line in phase space. The scheme is based on a resonant bichromatic excitation of each trapped ion that generates displacement and squeezing in the vibrational motion conditioned to each internal state. In this paper, we also show that such a method can be used for the engineering of motional quantum states.
Rapid Drinking Devices Constructed from I.V. Bags and Plastic Squeeze Bottles,
1985-04-01
i D-153 652 RAPID DRINKING DEVICES CONSTRUCTED FROM IY BAS AND 1/1 I PLASTIC SQUEEZE BOTTLES (U) A MY RESEARCH INST OF I ENVIRONMENTAL MEDICINE...TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVEREDLf Rapid Drinking Devices Constructed Fram I.V. ( Bags and Plastic Squeeze Bottles 6...running. The primary problem with using a plastic water bottle during a race is that it ~ must be held upright and squeezed tightly while the runner
Spin Squeezing of Atomic Ensembles via Nuclear-Electronic Spin Entanglement
DEFF Research Database (Denmark)
Fernholz, Thomas; Krauter, Hanna; Jensen, K.;
2008-01-01
We demonstrate spin squeezing in a room temperature ensemble of ≈1012 cesium atoms using their internal structure, where the necessary entanglement is created between nuclear and electronic spins of each individual atom. This state provides improvement in measurement sensitivity beyond the standard...... quantum limit for quantum memory experiments and applications in quantum metrology and is thus a complementary alternative to spin squeezing obtained via interatom entanglement. Squeezing of the collective spin is verified by quantum state tomography....
Symplectic Group Representation of the Two-Mode Squeezing Operator in the Coherent State Basis
Institute of Scientific and Technical Information of China (English)
FAN Hong-Yi; CHEN Jun-Hua
2003-01-01
We find that the coherent state projection operator representation of the two-mode squeezing operator constitutes a loyal group representation of symplectic group, which is a remarkable property of the coherent state. As a consequence, the resultant effect of successively applying two-mode squeezing operators are equivalent to a single squeezing in the two-mode Fock space. Generalization of this property to the 2n-mode case is also discussed.
Institute of Scientific and Technical Information of China (English)
He Guang-Qiang; Zhu Si-Wei; Guo Hong-Bin; Zeng Gui-Hua
2008-01-01
For the beam splitter attack strategy against quantum key distribution using two-mode squeezed states, the analytical expression of the optimal beam splitter parameter is provided in this paper by applying the Shannon information theory. The theoretical secret information rate after error correction and privacy amplification is given in terms of the squeezed parameter and channel parameters. The results show that the two-mode squeezed state quantum key distribution is secure against an optimal beam splitter attack.
Bell's Inequalities for Continuous-Variable Systems in Generic Squeezed States
Martin, Jerome
2016-01-01
Bell's inequality for continuous-variable bipartite systems is studied. The inequality is expressed in terms of pseudo-spin operators and quantum expectation values are calculated for generic two-mode squeezed states characterized by a squeezing parameter $r$ and a squeezing angle $\\varphi$. Allowing for generic values of the squeezing angle is especially relevant when $\\varphi$ is not under experimental control, such as in cosmic inflation, where small quantum fluctuations in the early Universe are responsible for structures formation. Compared to previous studies restricted to $\\varphi=0$ and to a fixed orientation of the pseudo-spin operators, allowing for $\\varphi\
Optimization of Squeeze Casting Parameters for 2017 A Wrought Al Alloy Using Taguchi Method
Directory of Open Access Journals (Sweden)
Najib Souissi
2014-04-01
Full Text Available This study applies the Taguchi method to investigate the relationship between the ultimate tensile strength, hardness and process variables in a squeeze casting 2017 A wrought aluminium alloy. The effects of various casting parameters including squeeze pressure, melt temperature and die temperature were studied. Therefore, the objectives of the Taguchi method for the squeeze casting process are to establish the optimal combination of process parameters and to reduce the variation in quality between only a few experiments. The experimental results show that the squeeze pressure significantly affects the microstructure and the mechanical properties of 2017 A Al alloy.
De Siena, S; Illuminati, F; Siena, Silvio De; Lisi, Antonio Di; Illuminati, Fabrizio
2002-01-01
We introduce nonlinear canonical transformations that yield effective Hamiltonians of multiphoton down conversion processes, and we define the associated non-Gaussian multiphoton squeezed states as the coherent states of the multiphoton Hamiltonians. We study in detail the four-photon processes and the associated non-Gaussian four-photon squeezed states. The realization of squeezing, the behavior of the field statistics, and the structure of the phase space distributions show that these states realize a natural four-photon generalization of the two-photon squeezed states.
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.
Directory of Open Access Journals (Sweden)
Schnabel Roman
2013-08-01
Full Text Available This contribution reviews our recent progress on the generation of squeezed light [1], and also the recent squeezed-light enhancement of the gravitational wave detector GEO 600 [2]. GEO 600 is currently the only GW observatory operated by the LIGO Scientific Collaboration in its search for gravitational waves. With the help of squeezed states of light it now operates with its best ever sensitivity, which not only proves the qualification of squeezed light as a key technology for future gravitational wave astronomy but also the usefulness of quantum entanglement.
Directory of Open Access Journals (Sweden)
Reza korrang beheshti
2014-06-01
Full Text Available Although there is not a fully developed theory of evil in Plato, some various remarks are interspersed throughout his dialogues which provided the main materials for subsequent Platonists to elaborate a systematic doctrine of evil. Proclus is the most distinguished philosopher of the later Neoplatonism whose view became authoritative within the School and thus is most representative of the Neoplatonic doctrine of evil. By a critical assessment of the antecedent theories of evil, Proclus attempts to give a monistic interpretation of Platonic remarks on the problem of evil. According to his explanation, the higher degrees and principles of Being are only and purely good and are not the causes of evils but the good things for all things alone. Evils, however, exist necessarily but only among particular beings in a relative, parasitic, accidental way and dependent upon the good. The parasitic accidental existence of evil does not have a real efficient cause. It arises due to an asymmetry between the activities of the several faculties or powers of a complex particular being. Moreover, the existence of evil is so mixed with and dependent upon the good that despite its opposition to the good, contributes, in its own manner, to the fulfillment of goodness of the whole Universe, being thus reconcilable with Divine Providence and Efficiency.
A short remark on the band structure of free-edge platonic crystals
Smith, Michael J. A.; Meylan, Michael H.; McPhedran, Ross C.; Poulton, Chris G.
2014-10-01
A corrected version of the multipole solution for a thin plate perforated in a doubly periodic fashion is presented. It is assumed that free-edge boundary conditions are imposed at the edge of each cylindrical inclusion. The solution procedure given here exploits a well-known property of Bessel functions to obtain the solution directly, in contrast to the existing incorrect derivation. A series of band diagrams and an updated table of values are given for the resulting system (correcting known publications on the topic), which shows a spectral band at low frequency for the free-edge problem. This is in contrast to clamped-edge boundary conditions for the same biharmonic plate problem, which features a low-frequency band gap. The numerical solution procedure outlined here is also simplified relative to earlier publications, and exploits the spectral properties of complex-valued matrices to determine the band structure of the structured plate.
Variance squeezing and entanglement of the XX central spin model
Energy Technology Data Exchange (ETDEWEB)
El-Orany, Faisal A A [Department of Mathematics and Computer Science, Faculty of Science, Suez Canal University, Ismailia (Egypt); Abdalla, M Sebawe, E-mail: m.sebaweh@physics.org [Mathematics Department, College of Science, King Saud University PO Box 2455, Riyadh 11451 (Saudi Arabia)
2011-01-21
In this paper, we study the quantum properties for a system that consists of a central atom interacting with surrounding spins through the Heisenberg XX couplings of equal strength. Employing the Heisenberg equations of motion we manage to derive an exact solution for the dynamical operators. We consider that the central atom and its surroundings are initially prepared in the excited state and in the coherent spin state, respectively. For this system, we investigate the evolution of variance squeezing and entanglement. The nonclassical effects have been remarked in the behavior of all components of the system. The atomic variance can exhibit revival-collapse phenomenon based on the value of the detuning parameter.
Deterministic Quantum Key Distribution Using Gaussian-Modulated Squeezed States
Institute of Scientific and Technical Information of China (English)
何广强; 朱俊; 曾贵华
2011-01-01
A continuous variable ping-pong scheme, which is utilized to generate deterministic private key, is proposed. The proposed scheme is implemented physically by using Ganssian-modulated squeezed states. The deterministic char- acteristic, i.e., no basis reconciliation between two parties, leads a nearly two-time efficiency comparing to the standard quantum key distribution schemes. Especially, the separate control mode does not need in the proposed scheme so that it is simpler and more available than previous ping-pong schemes. The attacker may be detected easily through the fidelity of the transmitted signal, and may not be successful in the beam splitter attack strategy.
Squeezing molecularly thin alkane lubrication films: Layering transistions and wear
DEFF Research Database (Denmark)
Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.
2004-01-01
The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C(3)H(8); C(4)H(10); C(8)H(18); C(9)H(20); C(10)H......(22); C(12)H(26), and C(14)H(30) confined between smooth gold surfaces. We observe well-defined molecular layers develop in the lubricant film when the width of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous changes in the number n of lubricant...
Baryon Acoustic Peak and the Squeezed Limit Bispectrum
Mirbabayi, Mehrdad; Zaldarriaga, Matias
2014-01-01
In the non-relativistic regime, pertinent to the large scale structure of the Universe, the leading effect of a long-wavelength perturbation $\\delta(\\lambda_L)$ on short distance physics is a uniform acceleration $\\propto \\lambda_L \\delta(\\lambda_L)$. Typically, this has no effect on statistical averages at equal time since a uniform acceleration results in a uniform translation -- a reasoning that has been formalized as a "consistency condition" on the cosmological correlation functions. This naive expectation fails in the presence of the baryon acoustic feature provided $\\lambda_L < \\ell_{\\rm BAO}$. We derive the squeezed limit of correlation functions in this regime.
Theoretical Analysis of Magnetorheological Damper Characteristics in Squeeze Mode
Directory of Open Access Journals (Sweden)
Sapiński Bogdan
2015-06-01
Full Text Available The paper summarises the theoretical study of a magnetorheological (MR damper operated in squeeze mode, intended to be used as an actuator in a semi-active mount system in a car motor. The structural design and operating principle of the damper are described and a simplified model of the MR fluid flow in the gap is presented. The plots of the damper force generated by the MR damper are obtained for monoharmonic piston motion with respect to the centre point of the gap height and in the conditions of the control coil being supplied with direct current.
Squeezing of higher order Hermite-Gauss modes
DEFF Research Database (Denmark)
Lassen, Mikael Østergaard
2008-01-01
The present paper gives an overview of the experimental generation of squeezing in higher order Hermite-Gaussian modes with an optical parametric ampli¯er (OPA). This work was awarded with The European Optical Society (EOS) price 2007. The purpose of the prize is to encourage a European dimension...... in research in pure and applied optics. The EOS prize is awarded based on the selection criteria of high professionalism, academic and technical quality. Following the EOS Prize rules, the conditions for eligibility are that the work was performed in Europe and that it is published under the auspices...
Euro Area——Fiscal Squeeze,Export Boost
Institute of Scientific and Technical Information of China (English)
Samra Al Harthy; Sarah Hewin
2010-01-01
@@ Europe's fiscat squeeze: how damaging? Tight fiscal versus loose monetary conditions The euro-area economy faces countervailing forces,and growth over the next two years is likely to be characterised by diverging trends among its member states.This divergence has been evident in the staggered return to growth within the region,with Germany and France back in positive territory by Q2-2009,while Spain pulled out of recession in Q1-2010.Business confidence surveys and purchasing managers indices point to buoyant growth for the region in Q2-2010,and strong orders should sustain the momentum in Q3.
Lipid corralling and poloxamer squeeze-out in membranes
DEFF Research Database (Denmark)
Wu, G.H.; Majewski, J.; Ege, C.;
2004-01-01
Using x-ray scattering measurements we have quantitatively determined the effect of poloxamer 188 (P188), a polymer known to seal damaged membranes, on the structure of lipid monolayers. P188 selectively inserts into low lipid-density regions of the membrane and "corrals" lipid molecules to pack...... tightly, leading to unexpected Bragg peaks at low nominal lipid density and inducing lipid/poloxamer phase separation. At tighter lipid packing, the once inserted P188 is squeezed out, allowing the poloxamer to gracefully exit when the membrane integrity is restored....
Entropy production and thermodynamic power of the squeezed thermal reservoir
Manzano, Gonzalo; Galve, Fernando; Zambrini, Roberta; Parrondo, Juan M. R.
2016-05-01
We analyze the entropy production and the maximal extractable work from a squeezed thermal reservoir. The nonequilibrium quantum nature of the reservoir induces an entropy transfer with a coherent contribution while modifying its thermal part, allowing work extraction from a single reservoir, as well as great improvements in power and efficiency for quantum heat engines. Introducing a modified quantum Otto cycle, our approach fully characterizes operational regimes forbidden in the standard case, such as refrigeration and work extraction at the same time, accompanied by efficiencies equal to unity.
From fractional Fourier transformation to quantum mechanical fractional squeezing transformation
Institute of Scientific and Technical Information of China (English)
吕翠红; 范洪义; 李东韡
2015-01-01
By converting the triangular functions in the integration kernel of the fractional Fourier transformation to the hy-perbolic function, i.e., tanα→tanhα, sinα→sinhα, we find quantum mechanical fractional squeezing transformation (FrST) which satisfies additivity. By virtue of the integration technique within ordered product of operators (IWOP) wederive the unitary operator responsible for the FrST, which is composite and is made of eiπa†a/2 and exp[ iα2 (a2+a†2)]. The FrST may be implemented in combinations of quadratic nonlinear crystals with different phase mismatches.
Multiscale Modeling of Red Blood Cells Squeezing through Submicron Slits
Peng, Zhangli; Lu, Huijie
2016-11-01
A multiscale model is applied to study the dynamics of healthy red blood cells (RBCs), RBCs in hereditary spherocytosis, and sickle cell disease squeezing through submicron slits. This study is motivated by the mechanical filtration of RBCs by inter-endothelial slits in the spleen. First, the model is validated by comparing the simulation results with experiments. Secondly, the deformation of the cytoskeleton in healthy RBCs is investigated. Thirdly, the mechanisms of damage in hereditary spherocytosis are investigated. Finally, the effects of cytoplasm and membrane viscosities, especially in sickle cell disease, are examined. The simulations results provided guidance for future experiments to explore the dynamics of RBCs under extreme deformation.
Effective thermodynamics of isolated entangled squeezed and coherent states
Seroje, King Karl R; Paraan, Francis N C
2015-01-01
The R\\'enyi entanglement entropy is calculated exactly for mode-partitioned isolated systems such as the two-mode squeezed state and the multi-mode Silbey-Harris polaron ansatz state. Effective thermodynamic descriptions of the correlated partitions are constructed to present quantum information theory concepts in the language of thermodynamics. Boltzmann weights are obtained from the entanglement spectrum by deriving the exact relationship between an effective temperature and the physical entanglement parameters. The partition function of the resulting effective thermal theory can be obtained directly from the single-copy entanglement.
Experimental evidence for Raman-induced limits to efficient squeezing in optical fibers
DEFF Research Database (Denmark)
Dong, R.; Heersink, J.; Corney, J.
2008-01-01
We report new experiments on polarization squeezing using ultrashort photonic pulses in a single pass of a birefringent fiber. We measure what is to our knowledge a record squeezing of -6.8 +/- 0.3 dB in optical fibers which when corrected for linear losses is -10.4 +/- 0.8 dB. The measured...
Enhancement of Squeezing in Two-Photon Jaynes-Cummings Model with Atomic Measurement
Institute of Scientific and Technical Information of China (English)
YE Sai-Yun
2006-01-01
We investigate the squeezing properties of the cavity field in the degenerate two-photon Jaynes-Cummings model. Compared with the one-photon Jaynes-Cummings model, the squeezing is more pronounced in the case of two-photon Jaynes-Cummings model under certain conditions.
Teleportation of a two-particle four-component squeezed vacuum state by linear optical elements
Institute of Scientific and Technical Information of China (English)
Huina Chen; Jinming Liu
2009-01-01
We present a linear optical scheme for achieving a unity fidelity teleportation of a two-particle four component squeezed vacuum state using two entangled squeezed vacuum states as quantum channel.The devices used are beam splitters and ideal photon detectors capable of distinguishing between odd and even photon numbers.Moreover,we also obtain the success probability of the teleportation scheme.
Transforming squeezed light into large-amplitude coherent-state superposition
DEFF Research Database (Denmark)
Nielsen, Anne Ersbak Bang; Mølmer, Klaus
2007-01-01
A quantum superposition of two coherent states of light with small amplitude can be obtained by subtracting a photon from a squeezed vacuum state. In experiments this preparation can be made conditioned on the detection of a photon in the field from a squeezed light source. We propose and analyze...
Measurement Induced Enhancement of Squeezing in Nondegenerate Two-Photon Jaynes-Cummings Model
Institute of Scientific and Technical Information of China (English)
YE Sai-Yun
2006-01-01
Squeezing properties in the nondegenerate two-photon Jaynes-Cummings model are investigated. The effects of direct selective atomic measurement and the application of the classical field followed by atomic measurement are analyzed. Different values of the parameters of the classical field are taken into account. It is found that the field squeezing can be enhanced by measurement.
Analytical Study of Two-Mode Thermal Squeezed States and Black Holes
Venkataratnam, K. K.
2017-02-01
We study the two-mode thermal squeezed states formalism to examine the particle creation by black holes.We also study the entropy generation and derive an equation for Hawking temperature in terms of squeezed parameter and an associated temperature dependent parameters.
Maximal entanglement of squeezed vacuum states via swapping with number-phase measurement
Kitagawa, A; Kitagawa, Akira; Yamamoto, Katsuji
2002-01-01
We propose a method to realize entanglement via swapping from a pair of squeezed vacuum states by performing number sum and phase difference measurements. The resultant states are maximally entangled by adjusting the two squeezing parameters to the same value. We then describe a teleportation protocol by using the entangled states prepared in this way.
Bounds for entanglement of formation of two mode squeezed thermal states
Chen, X Y; Chen, Xiao-Yu; Qiu, Pei-liang
2003-01-01
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.
SQUEEZING PROPERTIES OF A TRAPPED ION IN THE STANDING-WAVE LASER
Institute of Scientific and Technical Information of China (English)
FANG MAO-FA; LIU XIANG
2001-01-01
We investigate the squeezing properties of a trapped ion in a standing-wave laser. Our results show that the squeezing of a trapped ion in the standing-wave laser is dependent on its position in the latter, the detuning parameter and the initial average phonon number.
Pereira, A V; Pereira, S A; Gremião, I D F; Campos, M P; Ferreira, A M R
2012-11-01
This study compared the sensitivity of acetate tape impression and skin squeezing with that of deep skin scraping for the diagnosis of demodicosis in dogs. Demodex canis was detected in 100% of acetate tape impressions obtained after skin squeezing and in 90% of deep skin scrapings. There was a significant difference (P scraping and is an alternative diagnostic method for canine demodicosis.
First long-term application of squeezed states of light in a gravitational-wave observatory.
Grote, H; Danzmann, K; Dooley, K L; Schnabel, R; Slutsky, J; Vahlbruch, H
2013-05-03
We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German-British detector GEO 600 during a period of three months from June to August 2011, when GEO 600 was performing an observational run together with the French-Italian Virgo detector. In a second period, the squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum was applied for 90.2% (205.2 days total) of the time that science-quality data were acquired with GEO 600. A sensitivity increase from squeezed vacuum application was observed broadband above 400 Hz. The time average of gain in sensitivity was 26% (2.0 dB), determined in the frequency band from 3.7 to 4.0 kHz. This corresponds to a factor of 2 increase in the observed volume of the Universe for sources in the kHz region (e.g., supernovae, magnetars). We introduce three new techniques to enable the long-term application of squeezed light, and show that the glitch rate of the detector did not increase from squeezing application. Squeezed vacuum states of light have arrived as a permanent application, capable of increasing the astrophysical reach of gravitational-wave detectors.
Institute of Scientific and Technical Information of China (English)
LIANG Mai-Lin; YUAN Bing
2002-01-01
A new way to calculate the nonzero temperature quantum fluctuations of the time-dependent harmonicoscillator is proposed and the properties of squeezing are exactly given. The method is applied to the capacitive coupledelectric circuit. It is explicitly shown that squeezing can appear and the squeezing parameters are related to the physicalquantities of the coupled circuit.
Zhang, Xuezhi; Wang, Meng; Sun, Zhizhong; Hu, Henry
Squeeze cast light alloys has been approved for advanced engineering design of light integrity automotive applications. An understanding of the effect of section thicknesses on mechanical properties of squeeze cast magnesium alloys is essential for proper design of different applications. The present work studied the microstructure and tensile properties of magnesium alloy AM60 with different section thickness of 6, 10 and 20mm squeeze cast under an applied pressure of 30MPa. The results of tensile testing indicate that the yield strength (YS), ultimate tensile strength (UTS) and elongation (Ef) increase with a decreasing in section thicknesses of squeeze cast AM60. The microstructure analysis shows that the improvement in the tensile properties of squeeze cast AM60 is mainly attributed to the low level of gas porosity and the high content of eutectic phases and fine grain structure which resulted from high solidification rates taking place in the thin section.
The Effect of Incoherent Population Pumping on Squeezing in Resonance Fluorescence
Institute of Scientific and Technical Information of China (English)
CHEN Zhaoyang; ZHANG Jingtao; XU Zhizhan
2000-01-01
The effect of incoherent population pumping on the steady-state population inversion and the quadrature squeezing spectra produced in the resonance fluorescence of a two-level atom is investigated. In the presence of incoherent population pumping, the steady-state population inversion is increased for small frequency detuning but is not changed for large frequency detuning. For resonant excitation at low intensities, the weak incoherent pumping degrades the degree of the squeezing and shifts the position of the maximum squeezing; for off-resonant excitation at strong intensities, the weak incoherent pumping hardly changes the squeezing spectra. But when the incoherent pumping is strong the squeezing may be completely destroyed for both cases.
First beam test of a combined ramp and squeeze at LHC
Wenninger, Jorg; Coello De Portugal - Martinez Vazquez, Jaime Maria; Gorzawski, Arkadiusz; Redaelli, Stefano; Schaumann, Michaela; Solfaroli Camillocci, Matteo; CERN. Geneva. ATS Department
2015-01-01
With increasing maturity of LHC operation it is possible to envisage more complex beam manipulations. At the same time operational efficiency receives increasing attention. So far ramping the beams to their target energy and squeezing the beams to smaller or higher beta are decoupled at the LHC. (De-)squeezing is always performed at the target energy, currently 6.5 TeV. Studies to combine the ramp and squeeze processes have been made for the LHC since 2011, but so far no experimental test with beam had ever performed. This note describes the first machine experiment with beam aiming at validating the combination of ramp and squeeze, the so-called combined ramp and squeeze (CRS).
Couple Stress Squeeze Films with VPD in a Curved Circular Geometry
Directory of Open Access Journals (Sweden)
Vimala Ponnuswamy
2015-01-01
Full Text Available The problem of couple stress squeeze films considering viscosity pressure dependence (VPD has been analysed in a curved circular geometry. Using Stokes microcontinuum theory and the Barus formula, the Reynolds type equation has been derived. The approximate analytical expressions for the squeeze film pressure and load carrying capacity are obtained using a perturbation technique. The numerical solutions for the squeeze film pressure and load carrying capacity are presented for the sinusoidal motion of the upper curved disk, assuming an exponential form for the curvature. The effects of curvature, the non-Newtonian couple stresses, and VPD and their combined effects are investigated through the squeeze film pressure and the load carrying capacity of the squeeze film.
Dynamical Relation between Quantum Squeezing and Entanglement in Coupled Harmonic Oscillator System
Directory of Open Access Journals (Sweden)
Lock Yue Chew
2014-04-01
Full Text Available In this paper, we investigate into the numerical and analytical relationship between the dynamically generated quadrature squeezing and entanglement within a coupled harmonic oscillator system. The dynamical relation between these two quantum features is observed to vary monotically, such that an enhancement in entanglement is attained at a fixed squeezing for a larger coupling constant. Surprisingly, the maximum attainable values of these two quantum entities are found to consistently equal to the squeezing and entanglement of the system ground state. In addition, we demonstrate that the inclusion of a small anharmonic perturbation has the effect of modifying the squeezing versus entanglement relation into a nonunique form and also extending the maximum squeezing to a value beyond the system ground state.
Influence of the virtual photon field on the squeezing properties of an atom laser
Institute of Scientific and Technical Information of China (English)
Zhao Jian-Gang; Sun Chang-Yong; Wen Ling-Hua; Liang Bao-Long
2009-01-01
This paper investigates the squeezing properties of an atom laser without rotating-wave approximation in the system of a binomial states field interacting with a two-level atomic Bose-Einstein condensate. It discusses the influences of atomic eigenfrequency, the interaction intensity between the optical field and atoms, parameter of the binomial states field and virtual photon field on the squeezing properties. The results show that two quadrature components of an atom laser can be squeezed periodically. The duration and the degree of squeezing an atom laser have something to do with the atomic eigenfrequency and the parameter of the binomial states field, respectively. The collapse and revival frequency of atom laser fluctuation depends on the interaction intensity between the optical field and atoms. The effect of the virtual photon field deepens the depth of squeezing an atom laser.
Ahluwalia, Balpreet Singh; McCourt, Peter; Oteiza, Ana; Wilkinson, James S; Huser, Thomas R; Hellesø, Olav Gaute
2015-01-07
Red blood cells squeeze through micro-capillaries as part of blood circulation in the body. The deformability of red blood cells is thus critical for blood circulation. In this work, we report a method to optically squeeze red blood cells using the evanescent field present on top of a planar waveguide chip. The optical forces from a narrow waveguide are used to squeeze red blood cells to a size comparable to the waveguide width. Optical forces and pressure distributions on the cells are numerically computed to explain the squeezing process. The proposed technique is used to quantify the loss of blood deformability that occurs during blood storage lesion. Squeezing red blood cells using waveguides is a sensitive technique and works simultaneously on several cells, making the method suitable for monitoring stored blood.
Sideband cooling beyond the quantum backaction limit with squeezed light
Clark, Jeremy B.; Lecocq, Florent; Simmonds, Raymond W.; Aumentado, José; Teufel, John D.
2017-01-01
Quantum fluctuations of the electromagnetic vacuum produce measurable physical effects such as Casimir forces and the Lamb shift. They also impose an observable limit—known as the quantum backaction limit—on the lowest temperatures that can be reached using conventional laser cooling techniques. As laser cooling experiments continue to bring massive mechanical systems to unprecedentedly low temperatures, this seemingly fundamental limit is increasingly important in the laboratory. Fortunately, vacuum fluctuations are not immutable and can be ‘squeezed’, reducing amplitude fluctuations at the expense of phase fluctuations. Here we propose and experimentally demonstrate that squeezed light can be used to cool the motion of a macroscopic mechanical object below the quantum backaction limit. We first cool a microwave cavity optomechanical system using a coherent state of light to within 15 per cent of this limit. We then cool the system to more than two decibels below the quantum backaction limit using a squeezed microwave field generated by a Josephson parametric amplifier. From heterodyne spectroscopy of the mechanical sidebands, we measure a minimum thermal occupancy of 0.19 ± 0.01 phonons. With our technique, even low-frequency mechanical oscillators can in principle be cooled arbitrarily close to the motional ground state, enabling the exploration of quantum physics in larger, more massive systems.
Squeezed light from a diamond-turned monolithic cavity
Brieussel, A; Campbell, G; Guccione, G; Janousek, J; Hage, B; Buchler, B C; Treps, N; Fabre, C; Fang, F Z; Li, X Y; Symul, T; Lam, P K
2016-01-01
For some crystalline materials, a regime can be found where continuous ductile cutting is feasible. Using precision diamond turning, such materials can be cut into complex optical components with high surface quality and form accuracy. In this work we use diamond-turning to machine a monolithic, square-shaped, doubly-resonant $LiNbO_3$ cavity with two flat and two convex facets. When additional mild polishing is implemented, the Q-factor of the resonator is found to be limited only by the material absorption loss. We show how our monolithic square resonator may be operated as an optical parametric oscillator that is evanescently coupled to free-space beams via birefringent prisms. The prism arrangement allows for independent and large tuning of the fundamental and second harmonic coupling rates. We measure $2.6\\pm0.5$ dB of vacuum squeezing at 1064 nm using our system. Potential improvements to obtain higher degrees of squeezing are discussed.
Coherent quantum squeezing due to the phase space noncommutativity
Bernardini, Alex E.; Mizrahi, Salomon S.
2015-06-01
The effects of general noncommutativity of operators on producing deformed coherent squeezed states is examined in phase space. A two-dimensional noncommutative (NC) quantum system supported by a deformed mathematical structure, similar to that of Hadamard billiard, is obtained and the components behaviour is monitored in time. It is assumed that the independent degrees of freedom are two free 1D harmonic oscillators (HOs), so the system Hamiltonian does not contain interaction terms. Through the NC deformation parameterized by a Seiberg-Witten transform on the original canonical variables, one gets the standard commutation relations for the new ones, such that the obtained, new, Hamiltonian represents two interacting 1D HOs. By admitting that one HO is inverted relatively to the other, we show that their effective interaction induces a squeezing dynamics for initial coherent states imaged in the phase space. A suitable pattern of logarithmic spirals is obtained and some relevant properties are discussed in terms of Wigner functions, which are essential to put in evidence the effects of the noncommutativity.
Nonclassical properties and decoherence of fields in photon-added squeezing-enhanced thermal states
Wang, Zhen; Meng, Xiang-Guo; Li, Heng-Mei; Yuan, Hong-Chun
2014-04-01
We put forward the photon-added squeezing-enhanced thermal states (PASETS) theoretically by adding photon to the squeezed enhancing thermal states (SETS) repeatedly. Based on the normally ordered density operator of PASETS, we investigate the nonclassical behavior of the PASETS by evaluating, both analytically and numerically, Mandel's Q-parameter, photon-number distribution (PND), and Wigner function (WF). It is found that smaller squeezing parameter r and thermal photon number nc can lead to more chance of the appearance of sub-Poissonian statistics. And it is shown that the PND of PASETS exhibit more remarkable oscillations than that of SETS in stronger squeezing case. The WF exhibit partial negativity in phase space and the squeezing parameter r can result in both squeezing and rotating effect. By investigating the fidelity between PASETS and SETS shows that the fidelity tender to steady values in the high value of squeezing parameter or thermal photon number. In addition, the decoherence effect on the PASETS is examined by the time-evolution of the analytical WF in thermal channel. The results show that the PASETS shall lose nonclassicality and non-Gaussianity and reduce to classical states with Gaussian distribution after sufficient time interaction with the thermal noise. And larger photon-added number or thermal photon number shall render shorter decoherence time.
Quantum control of spin-nematic squeezing in a dipolar spin-1 condensate
Huang, Yixiao; Xiong, Heng-Na; Yang, Yang; Hu, Zheng-Da; Xi, Zhengjun
2017-01-01
Versatile controllability of interactions and magnetic field in ultracold atomic gases ha now reached an era where spin mixing dynamics and spin-nematic squeezing can be studied. Recent experiments have realized spin-nematic squeezed vacuum and dynamic stabilization following a quench through a quantum phase transition. Here we propose a scheme for storage of maximal spin-nematic squeezing, with its squeezing angle maintained in a fixed direction, in a dipolar spin-1 condensate by applying a microwave pulse at a time that maximal squeezing occurs. The dynamic stabilization of the system is achieved by manipulating the external periodic microwave pulses. The stability diagram for the range of pulse periods and phase shifts that stabilize the dynamics is numerical simulated and agrees with a stability analysis. Moreover, the stability range coincides well with the spin-nematic vacuum squeezed region which indicates that the spin-nematic squeezed vacuum will never disappear as long as the spin dynamics are stabilized. PMID:28233786
Atom-assisted quadrature squeezing of a mechanical oscillator inside a dispersive cavity
Biswas, Asoka; Chauhan, Anil Kumar
2016-05-01
Measurement of position of a mesoscopic harmonic oscillator below standard quantum limit in cavity optomechanics has seen a growing interest in recent times. If the oscillator is suspended inside the cavity (with both the mirrors fixed) at a position where the cavity frequency becomes extremum (a membrane-in-the-middle setup), large squeezing can be achieved by conditional measurement of thermal photons; however the cavity decay degrades such squeezing. Here we propose an atom-cavity-oscillator hybrid scheme, in which the effect of cavity decay is eliminated via dispersive coupling of the cavity mode. The atom in Λ configuration is considered to be trapped on either side of the membrane inside the cavity. We show that a considerable amount of squeezing (far beyond the 3 dB limit) can be achieved that is not affected by spontaneous emission of the atom. The squeezing depends upon the initial preparation of the atomic states. Further, the external classical fields, that drive the atomic transition and the cavity mode, control the degree of squeezing and can also lead to a strong effective atom-oscillator coupling. Effect of thermal phonon bath on squeezing is studied in terms of the squeezing spectrum. The results are supported by the detailed analytical calculations.
Energy Technology Data Exchange (ETDEWEB)
Stefszky, Michael; Buchler, Ben C; Symul, Thomas; Lam, Ping Koy [Quantum Optics Group, Department of Quantum Science, The Australian National University, ACT 0200 (Australia); Mow-Lowry, Conor M; McKenzie, Kirk; Chua, Sheon; McClelland, David E, E-mail: michael.stefszky@anu.edu.au [Centre for Gravitational Physics, Department of Quantum Science, The Australian National University, ACT 0200 (Australia)
2011-01-14
A squeezed light source requires properties such as high squeezing amplitude, high bandwidth and stability over time, ideally using as few resources, such as laser power, as possible. We compare three nonlinear materials, two of which have not been well characterized for squeezed state production, and also investigate the viability of doubly-resonant optical parametric oscillator cavities in achieving these requirements. A model is produced that provides a new way of looking at the construction of an optical parametric oscillator/optical parametric amplifier setup where second harmonic power is treated as a limited resource. The well-characterized periodically poled potassium titanyl phosphate (PPKTP) is compared in an essentially identical setup to two relatively new materials, periodically poled stoichiometric lithium tantalate (PPSLT) and 1.7% magnesium oxide doped periodically poled stoichiometric lithium niobate (PPSLN). Although from the literature PPSLT and PPSLN present advantages such as a higher damage threshold and a higher nonlinearity, respectively, PPKTP was still found to have the most desirable properties. With PPKTP, 5.8 dB of squeezing below the shot noise limit was achieved. With PPSLT, 5.0 dB of squeezing was observed but the power required to see this squeezing was much higher than expected. A technical problem with the PPSLN limited the observed squeezing to around 1.0 dB. This problem is discussed.
Platone interprete di se stesso. «Menone» 98a alla luce di «Fedro» 249b-c
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Lavinia Maggi
2016-01-01
Full Text Available La definizione di ἐπιστήμη come ὀρθὴ δόξα legata αἰτίας λογισμῷ, che compare in Menone 98a, presenta notevoli difficoltà interpretative non solo per quanto riguarda l’identificazione dell’αἰτία, ma anche per la possibilità o meno di scorgere sullo sfondo di tale enunciazione la teoria delle Idee (nella versione dei cosiddetti “dialoghi della maturità”. La questione può essere affrontata sia considerando il controverso passo all’interno del contesto più ampio del dialogo (dove compare per la prima volta la teoria dell’ἀνάμνησις, che alla teoria delle Idee è strettamente legata, ma anche in relazione a passi di altri dialoghi platonici, in particolare Fedro 249b-c: qui, dove l’epistemologia platonica si sviluppa secondo la teoria delle Idee, la volontà di Platone di alludere direttamente a Menone 98a sembra offrire una chiave interpretativa anche per quella precedente formulazione. La necessità di leggere ogni dialogo secondo le sue specificità (periodo di composizione, argomento principale, tipologia dei personaggi coinvolti non esclude infatti che, almeno in alcuni casi, Platone stabilisca dei collegamenti che consentano una continuità di lettura nel percorso di sviluppo del suo pensiero.
Squeeze casting of aluminum alloy A380: Microstructure and tensile behavior
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Li Fang
2015-09-01
Full Text Available A380 alloy with a relatively thick cross-section of 25 mm was squeeze cast using a hydraulic press with an applied pressure of 90 MPa. Microstructure and tensile properties of the squeeze cast A380 were characterized and evaluated in comparison with the die cast counterpart. Results show that the squeeze cast A380 possesses a porosity level much lower than the die cast alloy, which is disclosed by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength (UTS: 215.9 MPa and elongation (Ef: 5.4%, for the squeeze cast samples over those of the conventional high-pressure die cast part (UTS: 173.7 MPa, Ef: 1.0%. The analysis of tensile behavior shows that the squeeze cast A380 exhibits a high tensile toughness (8.5 MJ·m-3 and resilience (179.3 kJ·m-3 compared with the die cast alloy (toughness: 1.4 MJ·m-3, resilience: 140.6 kJ·m-3, despite that, during the onset of plastic deformation, the strain-hardening rate of the die cast specimen is higher than that of the squeeze cast specimens. The microstructure analyzed by the scanning electron microscopy (SEM shows that both the squeeze and die cast specimens contain the primary α-Al, Al2Cu, Al5FeSi phase and the eutectic Si phase. But, the Al2Cu phase present in the squeeze cast alloy is relatively large in size and quantity. The SEM fractography evidently reveals the ductile fracture features of the squeeze cast A380 alloy.
Effects of Velocity-Slip and Viscosity Variation in Squeeze Film Lubrication of Two Circular Plates
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R.R. Rao
2013-03-01
Full Text Available A generalized form of Reynolds equation for two symmetrical surfaces is taken by considering velocity-slip at the bearing surfaces. This equation is applied to study the effects of velocity-slip and viscosity variation for the lubrication of squeeze films between two circular plates. Expressions for the load capacity and squeezing time obtained are also studied theoretically for various parameters. The load capacity and squeezing time decreases due to slip. They increase due to the presence of high viscous layer near the surface and decrease due to low viscous layer.
Decoherence of two-qubit system in a non-Markovian squeezed reservoir
Institute of Scientific and Technical Information of China (English)
Wang Fa-Qiang; Zhang Zhi-Ming; Liang Rui-Sheng
2009-01-01
The decoherence of two initially entangled qubits coupled with a squeezed vacuum cavity separately is investigated exactly. The results show that, first, in principle, the disentanglement time decreases with the increase of squeeze parameter r, due to the augmenting of average photon number of every mode in the squeezed vacuum cavity. Second, there appear entanglement revivals after the complete disentanglement for the case of even parity initial Bell state, while there occur the entanglement decrcase and the entanglement revival before the complete disentanglement for the case of odd parity initial Bell state. The results are quite different from those for the case of qubits in a vacuum cavity.
Temperature and Thermal Stress Distribution for Metal Mold in Squeeze Casting Process
Institute of Scientific and Technical Information of China (English)
K.H.Chang; G.C.Jang; C.H.Lee; S.H.Lee
2008-01-01
In the squeeze casting process, loaded high pressure (over approximately 100 MPa) and high temperature influence the thermo-mechanical behavior and performance of the used metal mold. Therefore, to safely maintain the metal molds, the thermo-mechanical characteristics (temperature and thermal stress) of metal mold in the squeeze casting must be investigated. In this paper, temperature and thermal stress distribution of steel mold in squeeze casting process were investigated by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis considering temperature-dependent thermo- physical and mechanical properties of the steel mold.
Evolution of a two-mode squeezed vacuum in the amplitude dissipative channel
Institute of Scientific and Technical Information of China (English)
Jiang Nian-Quan; Fan Hong-Yi; Xi Liu-Sheng; Tang Long-Ying; Yuan Xian-Zhang
2011-01-01
For the first time we derive the dissipating result of an initial two-mode squeezed pure vacuum state passing through a two-mode amplitude dissipative channel described by the direct product of two independent single-mode master equations.Although these two master equations do not mix the two modes (there is no coupling between them),since the two-mode squeezed state is simultaneously an entangled state,the final state which emerges from passing this channel is a two-mode mixed density operator.The compact expression of the outcoming state is obtained,which manifestly shows that as time evolves,the squeezing effect decreases.
Zeno and Anti Zeno effect for a two level system in a squeezed bath
Mundarain, D F
2005-01-01
We discuss the appearance of Zeno (QZE) or anti-Zeno (QAE) effect in an exponentially decaying system. We consider the quantum dynamics of a continuously monitored two level system interacting with a squeezed bath. We find that the behavior of the system depends critically on the way in which the squeezed bath is prepared. For specific choices of the squeezing phase the system shows Zeno or anti-Zeno effect in conditions for which it would decay exponentially if no measurements were done. This result allows for a clear interpretation in terms of the equivalent spin system interacting with a fictitious magnetic field.
Strong relative intensity squeezing by 4-wave mixing in Rb vapor
McCormick, C F; Boyer, V; Lett, P D
2006-01-01
We have measured -3.5 dB (-8.1 dB corrected for losses) relative intensity squeezing between the probe and conjugate beams generated by stimulated, nondegenerate four-wave mixing in hot rubidium vapor. Unlike early observations of squeezing in atomic vapors based on saturation of a two-level system, our scheme uses a resonant nonlinearity based on ground-state coherences in a three-level system. Since this scheme produces narrowband, squeezed light near an atomic resonance it is of interest for experiments involving cold atoms or atomic ensembles.
Relative-intensity squeezing at audio frequencies using four-wave mixing in an atomic vapor
McCormick, C F; Lett, P D; Marino, A M
2007-01-01
We demonstrate the use of four-wave mixing in hot atomic vapor to generate up to -7.1 dB of measured relative-intensity squeezing. Due to its intrinsic simplicity, our system is strongly decoupled from environmental noise, and we observe more than -4 dB of squeezing down to frequencies as low as 5 kHz. This robust source of narrowband squeezed light may be useful for a variety of applications, such as coupling to atomic ensembles and enhancing the sensitivity of photothermal spectroscopy.
A compact 3.5-dB squeezed light source with atomic ensembles
Bao, Guzhi; Chen, Bing; Guo, Jinxian; Shen, Heng; Chen, Liqing; Zhang, Weiping
2015-01-01
We reported a compact squeezed light source consisting of an diode laser near resonant on 87Rb optical D1 transition and an warm Rubidium vapor cell. The -4dB vacuum squeezing at 795 nm via nonlinear magneto-optical rotation was observed when applying the magnetic field orthogonal to the propagation direction of the light beam. This compact squeezed light source can be potentially utilized in the quantum information protocols such as quantum repeater and memory, and quantum metrology such as atomic magnetometer.
Thermo Vacuum State for Describing the Density Operator of Photon-subtracted Squeezed Chaotic Light
Wan, Zhi-Long; Fan, Hong-Yi; Li, Heng-Mei; Wang, Zhen
2017-10-01
For the density operator describing s-photon-subtracted squeezed chaotic light (PSSCL) we search for its thermo vacuum state (a pure state) in the real-fictitious space. We find that it reduces to a thermo vacuum state of squeezed chaotic light when s = 0, and to a thermo vacuum state of the optical negative binomial field when no squeezing. The new thermo vacuum state simplifies calculating photon number average, quantum fluctuation and Mandel's Q parameter of PSSCL. Using the method of integration within ordered product (IWOP) of operators we also derive the normalization coefficient and explicitly analytical expressions of Wigner function for PSSCL.
Generation of squeezed-state superpositions via time-dependent Kerr nonlinearities
León-Montiel, R de J
2015-01-01
We put forward an experimental scheme for direct generation of optical squeezed coherent-state superpositions. The proposed setup makes use of an optical cavity, filled with a nonlinear Kerr medium, whose frequency is allowed to change during time evolution. By exactly solving the corresponding time-dependent anharmonic-oscillator Hamiltonian, we demonstrate that squeezed-state superpositions can be generated in an optical cavity. Furthermore, we show that the squeezing degree of the produced states can be tuned by properly controlling the frequency shift of the cavity, a feature that could be useful in many quantum information protocols, such as quantum teleportation and quantum computing.
Oscillation behaviour in the photon-number distribution of squeezed coherent states
Institute of Scientific and Technical Information of China (English)
Wang Shuai; Zhang Xiao-Yan; Fan Hong-Yi
2012-01-01
From the normally ordered form of the density operator of a squeezed coherent state(SCS),we directly derive the compact expression of the SCS's photon-number distribution(PND).Besides the known oscillation characteristics,we find that the PND is a periodic function with a period of π and extremely sensitive to phase.If the squeezing is strong enough,and the compound phase which is relevant to the complex squeezing and displacement parameters are assigned appropriate values,different oscillation behaviours in PND for even and odd photon numbers appear,respectively.
Phase Properties of Two-Mode Squeezing-Rotating Entangled Representation
Institute of Scientific and Technical Information of China (English)
YUAN Hong-Chun; LI Heng-Mei; QI Kai-Guo
2006-01-01
By virtue of the squeezing-rotating entangled representation, we mainly establish thc new two-mode phase operator and phase angle operator, which is a general form including the foregoing formalist in two-mode Fock space.In addition, the corresponding phase distribution function is given in the entangled representation. In terms of this definition, we also analyze the phase behavior of some simple two-mode states such as squeezing-rotating coherent state,squeezing-rotating vacuum state, and so on. It is found that the results exactly agree with the foregoing phase theory.
Spin squeezing and entanglement via hole-burning in atomic coherent states
Energy Technology Data Exchange (ETDEWEB)
Gerry, Christopher C. [Department of Physics and Astronomy, Lehman College, City University of New York, Bronx, NY 10468-1589 (United States)], E-mail: christopher.gerry@lehman.cuny.edu; Peart, Mark [Department of Physics and Astronomy, Lehman College, City University of New York, Bronx, NY 10468-1589 (United States)
2008-10-20
We study the generation of spin squeezing via the hole burning of selected Dicke states out of an atomic coherent state prepared for a collection of N two-level atoms or ions. The atoms or ions of the atomic coherent state are not entangled, but the removal of one or more Dicke states generates entanglement, and spin squeezing occurs for some ranges of the relevant parameters. Spin squeezing in a collection of two-level atoms or ions is of importance for precision spectroscopy.
RESONANCE RESPONSE OF ELECTRORHEOLOGICAL FLUIDS IN VERTICAL OSCILLATION SQUEEZE FLOW
Institute of Scientific and Technical Information of China (English)
Sun Jiu-xun; Cai Ling-cang; Wu Qiang; Jing Fu-qian
2000-01-01
The resonance effect of microcrystalline cellulose/castor oil electrorheological (ER) suspensions was studied in a compressed oscillatory squeeze flow under external electric fields. The resonance frequency first increases linearly with increasing external field, and then shift to high-field plateau. The amplitudes of resonance peak increase sharply with the applied fields in the range of 0.17-1.67kV/mm. The phase difference of the.reduced displacement relative to the excitation force inverses in the case of resonance. A viscoelasticity model of the ER suspensions, which offers both the equivalent stiffness and the viscous damping, should be responsible for the appearance of resonance. The influence of the electric field on the resonance frequency and the resonance hump is consistent qualitatively with the interpretation of our proposed model. Storage modulus G′ was presented for the purpose of investigating this influence.
Deterministic Squeezed States with Joint Measurements and Feedback
Cox, Kevin C; Weiner, Joshua M; Thompson, James K
2015-01-01
We demonstrate the creation of entangled or spin-squeezed states using a joint measurement and real-time feedback. The pseudo-spin state of an ensemble of $N= 5\\times 10^4$ laser-cooled $^{87}$Rb atoms is deterministically driven to a specified population state with angular resolution that is a factor of 5.5(8) (7.4(6) dB) in variance below the standard quantum limit for unentangled atoms -- comparable to the best enhancements using only unitary evolution. Without feedback, conditioning on the outcome of the joint pre-measurement, we directly observe up to 59(8) times (17.7(6) dB) improvement in quantum phase variance relative to the standard quantum limit for $N=4\\times 10^5$ atoms. This is the largest reported entanglement enhancement to date in any system.
Disclosing phonon squeezing by non-equilibrium optical experiments
Esposito, Martina; Zimmermann, Klaus; Giusti, Francesca; Randi, Francesco; Boschetto, Davide; Parmigiani, Fulvio; Floreanini, Roberto; Benatti, Fabio; Fausti, Daniele
2015-01-01
Fluctuations of the atomic positions are at the core of a large class of unusual material properties ranging from quantum para-electricity and charge density wave to, possibly, high temperature superconductivity. Their measurement in solids is subject of an intense scientific debate focused on the research of a methodology capable of establishing a direct link between the variance of the ionic displacements and experimentally measurable observables. Here we address this issue by means of non-equilibrium optical experiments performed in shot-noise limited regime. The variance of the time dependent atomic positions and momenta is directly mapped into the quantum fluctuations of the photon number of the scattered probing light. A fully quantum description of the non-linear interactions between photonic and phononic fields unveils evidences of squeezing of thermal phonons in $\\alpha-$quartz.
An Achromatic Telescopic Squeezing (ATS) Scheme For The LHC Upgrade
Fartoukh, S
2011-01-01
A novel optics concept has been invented and developed in the context of the LHC Upgrade studies. It offers an incredibly powerful and flexible machinery in order to squeeze β* in a symmetric or asymmetric way (so-called “round” or “flat” optics, respectively), while perfectly controlling the chromatic aberrations induced (off-momentum beta-beating, non-linear chromaticity, spurious dispersion due to the crossing angles). The basic principles of the scheme are described and a specific path for the LHC upgrade is built accordingly, only relying on the existing and well-characterized LHC-like technology, and based on the production of flat collision optics with very small β* (7.5 cm) in the plane perpendicular to the crossing plane.
Design of process parameters for direct squeeze casting
Institute of Scientific and Technical Information of China (English)
Milan Zhang; Shuming Xing Liming Xiao; Peiwei Bao; Wen Liu; Qiao Xin
2008-01-01
On the basis of the analysis of solidification interval and temperature distribution of components manufactured by the squeeze casting method, formulas for calculating the solidification interval and compaction pressure were deduced according to the principal request that the compaction pressure should be equal to or greater than the plastic deformation resistance of the forming component when solidification ended. The solidification interval was proven to be associated with many factors, such as weight of the component, specific heat of the alloy, latent heat, pouring temperature, component temperature at the end of solidification and heat-transfer coefficients. The compaction pressure was related to the strain rate, deformation temperature, and dimension of the de-forming component. The solidification interval and compaction pressure calculated by the formulas deduced in this article were adopted in the production of 45 steel bidirectional chapiter valves, and components with excellent performance were manufactured.
Heat Transfer in MHD Squeezing Flow using Brinkman Model
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Satish Chandra RAJVANSHI
2014-01-01
Full Text Available This study investigates squeezing flow of viscous incompressible fluid in a highly permeable medium between 2 parallel, permeable, unsteadily rotating plates in the presence of a magnetic field and radiation. The plates at time t* are separated by a distance H(1-at*1/2. Using a similarity transformation, the governing equations have been transformed into a system of non-linear ordinary differential equations. The resulting equations have been solved numerically by a shooting method. Graphs are presented to depict the temperature and heat transfer profiles. The results show a decline in the temperature profiles under the effect of enhanced radiation.doi:10.14456/WJST.2014.68
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Maher Kamel Nafeeh Al-Nassery م.د. ماهر كامل نافع الناصري
2015-06-01
Full Text Available Find addresses marked: (Platonic ideal applications in modern European painting -almadrsh abstract model provide the nature of the effect of thought on the Platonic ideal orientations school abstract aesthetic that made the beauty of a goal. The contained four chapters: the first chapter interested in the methodological framework for representing the search: Find which dealt with the problem of identifying the impact of Platonic philosophy in the school abstract. The search was confined to the limits of the study of philosophy and its impact on the school and abstract pictorial analysis models for the drawings of the year (1900-1950 m. The second chapter contained two sections, taking the first section: (Platonic philosophy by eating the views of philosophical idealism and attainable beauty ideal of absolute, while Me second section (b Schools of Modern Art through a review of artistic movements beginner Baromantekah and Impressionism through symbolism and Alouhoshih and Cubism and Expressionism and future Dadaism and Surrealism ending with stylized promised that references poignant. The third chapter Me Platonic ideal applications in drawing global online research procedures, which included: the research community and appointed, and research methodology, research and analysis of samples amounting to (5 of the plate. Contained in Chapter IV, on the search results, and conclusions, as well as recommendations and suggestions, the researchers have come to a number of findings and conclusions, including: I worked at 1- abstract (Mondrian to unforeseen forces through its focus on geometric shape as a form is open, and her cognitive effects of gaining character totally not partially. Figure 2 The abstract carries prescription beauty essence, what has the laws of repetition and symmetry, harmony, and Find College (sample No. 4 by stripping the shape neighborhood divisions based systems engineering, which serves as the essence and origin of the samples
Utility of Squeeze Flow in the Food Industry
Huang, T. A.
2008-07-01
Squeeze flow for obtaining shear viscosity on Newtonian and non-Newtonian fluids has long been established in the literature. Rotational shear flow using cone/plate, a set of parallel plates, or concentric cylinders all develop wall slip, shear fracture, or instability on food related materials such as peanut butter or mayonnaise. Viscosity data obtained using any one of the above mentioned set-ups is suspect or potentially results in significant error. They are unreliable to support or predict the textural differences perceived by consumer evaluation. RMS-800, from Rheometrics Inc., was employed to conduct the squeezing flow under constant speeds on a set of parallel plates. Viscosity data, over a broad range of shear rates, is compared between Hellmann's real (HRM) and light mayonnaise (HLM). The Consistency and shear-thinning indices, as defined in the Power-Law Model, were determined. HRM exhibits a more pronounced shear-thinning when compared to HLM yet the Consistency of HRM is significantly higher. Sensory evaluation by a trained expert panel ranked that adhesiveness and cohesiveness of HLM are significantly higher. It appears that the degree of shear thinning is one of the key rheological parameters in predicting the above mentioned difference in textural attributes. Error involved in determining viscosity from non-parallelism between two plates can be significant to affect the accuracy of the viscosity, in particular, shear-thinning index. Details are a subject for the next presentation. Nevertheless, the method is proven to be fast, rugged, simple, and reliable. It can be developed as a QC tool.
Squeeze Film Dampers Executing Small Amplitude Circular-Centered Orbits in High-Speed Turbomachinery
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Sina Hamzehlouia
2016-01-01
Full Text Available This work represents a pressure distribution model for finite length squeeze film dampers (SFDs executing small amplitude circular-centered orbits (CCOs with application in high-speed turbomachinery design. The proposed pressure distribution model only accounts for unsteady (temporal inertia terms, since based on order of magnitude analysis, for small amplitude motions of the journal center, the effect of convective inertia is negligible relative to unsteady (temporal inertia. In this work, the continuity equation and the momentum transport equations for incompressible lubricants are reduced by assuming that the shapes of the fluid velocity profiles are not strongly influenced by the inertia forces, obtaining an extended form of Reynolds equation for the hydrodynamic pressure distribution that accounts for fluid inertia effects. Furthermore, a numerical procedure is represented to discretize the model equations by applying finite difference approximation (FDA and to numerically determine the pressure distribution and fluid film reaction forces in SFDs with significant accuracy. Finally, the proposed model is incorporated into a simulation model and the results are compared against existing SFD models. Based on the simulation results, the pressure distribution and fluid film reaction forces are significantly influenced by fluid inertia effects even at small and moderate Reynolds numbers.
Principal shapes and squeezed limits in the effective field theory of large scale structure
Bertolini, Daniele; Solon, Mikhail P.
2016-11-01
We apply an orthogonalization procedure on the effective field theory of large scale structure (EFT of LSS) shapes, relevant for the angle-averaged bispectrum and non-Gaussian covariance of the matter power spectrum at one loop. Assuming natural-sized EFT parameters, this identifies a linear combination of EFT shapes—referred to as the principal shape—that gives the dominant contribution for the whole kinematic plane, with subdominant combinations suppressed by a few orders of magnitude. For the covariance, our orthogonal transformation is in excellent agreement with a principal component analysis applied to available data. Additionally we find that, for both observables, the coefficients of the principal shapes are well approximated by the EFT coefficients appearing in the squeezed limit, and are thus measurable from power spectrum response functions. Employing data from N-body simulations for the growth-only response, we measure the single EFT coefficient describing the angle-averaged bispectrum with 𝒪(10%) precision. These methods of shape orthogonalization and measurement of coefficients from response functions are valuable tools for developing the EFT of LSS framework, and can be applied to more general observables.
Dynamic analysis of squeeze film damper supported rotors using equivalent linearization
Energy Technology Data Exchange (ETDEWEB)
El-Shafei, A. (Cairo Univ., Giza (Egypt). Dept. of Mechanical Design and Production); Eranki, R.V. (Aluman Mill Products, Inc., Morris, IL (United States))
1994-07-01
The technique of equivalent linearization is presented in this paper as a powerful technique to perform nonlinear dynamic analysis of squeeze film damper (SFD) supported rotors using linear rotor-dynamic methods. Historically, it is customary to design SFDs for rotor-dynamic analysis by assuming circular-centered orbits, which is convenient in making the nonlinear damper coefficients time independent and thus can be used in an iterative approach to determine the rotor-dynamic characteristics. However, the general synchronous orbit is elliptic in nature due to possible asymmetry in the rotor support. This renders the nonlinear damper coefficients time dependent, which would require extensive numerical computation using numerical integration to determine the rotor dynamic characteristics. Alternatively, it is shown that the equivalent linearization, which is based on a least-squares approach, can be used to obtain time-independent damper coefficients for SFDs executing eccentric elliptic orbits, which are nonlinear in the orbit parameters. The resulting equivalent linear forces are then used in an iterative procedure to obtain the unbalance response of a rigid rotor-SFD system. Huge savings over numerical integration are reported for this simple rotor. The technique can be extended to be used in conjunction with currently available linear rotor-dynamic programs to determine the rotor-dynamic characteristics through iteration. It is expected that for multirotor multibearing systems this technique will result in even more economical computation.
Directory of Open Access Journals (Sweden)
Jin Huang
2012-01-01
Full Text Available Magnetorheological (MR disk-type isolating dampers are the semi-active control devices that use MR fluids to produce controllable squeezing force. In this paper, the analytical endeavor into the fluid dynamic modeling of an MR isolating damper is reported. The velocity and pressure distribution of an MR fluid operating in an axisymmetric squeeze model are analytically solved using a biviscosity constitutive model. Analytical solutions for the flow behavior of MR fluid flowing through the parallel channel are obtained. The equation for the squeezing force is derived to provide the theoretical foundation for the design of the isolating damper. The result shows that with the increase of the applied magnetic field strength, the squeezing force is increased.
Optimization of Squeeze Parameters and Modification of AlSi7Mg Alloy
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A. Zyska
2013-04-01
Full Text Available The paper present the examination results concerning mechanical properties of castings made of AlSi7MG alloy in correlation both with the most significant squeeze casting parameters and with the modification treatment. Experiments were planned and held according to the 23 factorial design. The regression equations describing the influence of the squeeze pressure, the mould temperature, and the quantity of strontium modifier on the strength and elongation of the examined alloy were obtained. It was found that the main factor controlling the strength increase is the squeeze pressure, while the plasticity (A5 of the alloy is affected most advantageously by modification. The application of modification treatment in squeeze casting technology enables for production of the slab-type castings made of AlSi7Mg alloy exhibiting strength at the level of 230 MPa and elongation exceeding 14%.
Amplification of gravitational waves signal in Michelson coherent-squeezed interferometer
Barak, R
2007-01-01
Gravitational waves reaching a Michelson interferometer are expected to induce a very small change in the length of its arms causing a phase shift between them, but it is very difficult to observe the extremely small phase shift signals produced. In the present letter we show that the gravitational waves signal could be amplified by orders of magnitude by using very special conditions for a coherent-squeezed Michelson interferometer in which the coherent state enters one port of the interferometer and the squeezed vacuum enters in the other port. We treat the case where without the gravitational induced phase shift the very strong coherent state goes out of one output port while the squeezed vacuum goes out the other output port (the ``dark'' port). While the phase shift produced by the gravitation waves does not give any significant change in the strong coherent output, the light intensity in the ``dark'' port is amplified with decreased fluctuations as the squeezing increases.
Higher-Order Squeezing in a Boson Coupled Two-Mode System
Chizhov, A. V.; Haus, J. W.; Yeong, K. C.
1996-01-01
We consider a model for nondegenerate cavity fields interacting through an intervening Boson field. The quantum correlations introduced in this manner are manifest through their higher-order correlation functions where a type of squeezed state is identified.
Squeezing of thermal fluctuations in four-wave mixing in a Λ scheme
Erukhimova, Maria; Tokman, Mikhail
2017-01-01
We theoretically investigated the mechanism of two-mode quadrature squeezing in a regime of four-wave mixing in a Λ scheme of three-level atoms embedded in a thermal reservoir. We demonstrated that the process of nonlinear transfer of noise from the low frequency of ground state splitting to the optical frequency is significant if the number of thermal photons at the low frequency is high. We have shown that correct calculation of the two-mode squeezing level taking into account both thermal noise and distortion of dissipative properties of the thermally excited medium resulted in a simple expression for the maximum squeezing level, which is defined by the ground-state coherence decay rate and the drive-field intensity. We found the optimal conditions for squeezing, in particular, the optimal density-length product of the active medium depending on the atomic relaxation parameters and the drive-field intensity.
Entanglement and Extreme Spin Squeezing for a Fluctuating Number of Indistinguishable Particles
Hyllus, Philipp; Smerzi, Augusto; Toth, Geza
2012-01-01
We extend the criteria for $k$-particle entanglement from the spin squeezing parameter presented in [A.S. S{\\o}rensen and K. M{\\o}lmer, Phys. Rev. Lett. {\\bf 86}, 4431 (2001)] to systems with a fluctating number of particles. We also discuss how other spin squeezing inequalities can be generalized to this situation. Further, we give an operational meaning to the bounds for cases where the individual particles cannot be addressed. As a by-product, this allows us to show that in spin squeezing experiments with cold gases the particles are typically distinguishable in practise. Our results justify the application of the S{\\o}rensen-M{\\o}lmer bounds in recent experiments on spin squeezing in Bose-Einstein condensates.
Dell'Anno, F; Illuminati, F; Anno, Fabio Dell'; Siena, Silvio De; Illuminati, Fabrizio
2004-01-01
Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper ``Structure of multiphoton quantum optics. I. Canonical formalism and homodyne squeezed states'', we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing non degenerate and degenerate multiphoton processes. We determine the coherent states associated to the canonical transformations, which generalize the non degenerate two--photon squeezed states. Such heterodyne multiphoton squeezed are defined as the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non Gaussian, highly non classical, entangled states. For a quadratic nonline...
Impact of backscattered light in a squeezing-enhanced interferometric gravitational-wave detector
Chua, S S Y; Barsotti, L; Sigg, D; Schofield, R M S; Frolov, V V; Kawabe, K; Evans, M; Meadors, G D; Factourovich, M; Gustafson, R; Smith-Lefebvre, N; Vorvick, C; Landry, M; Khalaidovski, A; Stefszky, M S; Mow-Lowry, C M; Buchler, B C; Shaddock, D A; Lam, P K; Schnabel, R; Mavalvala, N; McClelland, D E
2014-01-01
Squeezed states of light have been recently used to improve the sensitivity of laser interferometric gravitational-wave detectors beyond the quantum limit. To completely establish quantum engineering as a realistic option for the next generation of detectors, it is crucial to study and quantify the noise coupling mechanisms which injection of squeezed states could potentially introduce. We present a direct measurement of the impact of backscattered light from a squeezed-light source deployed on one of the 4 km long detectors of the Laser Interferometric Gravitational Wave Observatory (LIGO). We also show how our measurements inform the design of squeezed light sources compatible with the even more sensitive advanced detectors currently under construction, such as Advanced LIGO.
National Research Council Canada - National Science Library
Naduvinamani, Neminath Bujappa; Apparao, Siddangouda; Gundayya, Hiremath Ayyappa; Biradar, Shivraj Nagshetty
2015-01-01
In this paper, a theoretical study of the effect of pressure dependent viscosity on couple stress squeeze film lubrication between rough parallel plates is analyzed on the basis of Barus experimental results...
Discrete-time reservoir engineering with entangled bath and stabilising squeezed states
Miao, Zibo; Sarlette, Alain
2017-09-01
This theoretical proposal investigates how resonant interactions occurring when a harmonic oscillator is fed with a stream of entangled qubits allow us to stabilise squeezed states of the harmonic oscillator. We show that the properties of the squeezed state stabilised by this engineered reservoir, including the squeezing strength, can be tuned at will through the parameters of the ‘input’ qubits, albeit in tradeoff with the convergence rate. We also discuss the influence of the type of entanglement in the input from a pairwise case to a more widely distributed case. This paper can be read either as a proposal to stabilise squeezed states or as a step toward treating quantum systems with time-entangled reservoir inputs.
Garcia-Ferrer, F V; De Valcarcel, G J; Roldan, E; Garcia-Ferrer, Ferran V.; Perez-Arjona, Isabel; Valcarcel, German J. de; Roldan, Eugenio
2005-01-01
It is well known that the squeezing spectrum of the field exiting a nonlinear cavity can be directly obtained from the fluctuation spectrum of normally ordered products of creation and annihilation operators of the cavity mode. In this article we show that the output field squeezing spectrum can be derived also by combining the fluctuation spectra of any pair of s-ordered products of creation and annihilation operators. The interesting result is that the spectrum obtained in this way from the linearized Langevin equations is exact, and this occurs in spite of the fact that no s-ordered quasiprobability distribution verifies a true Fokker-Planck equation, i.e., the Langevin equations used for deriving the squeezing spectrum are not exact. The (linearized) intracavity squeezing obtained from any s-ordered distribution is also exact. These results are exemplified in the problem of dispersive optical bistability.
Prospect for detecting squeezed states of light created by a single atom in free space
Stobińska, Magdalena; Sondermann, Markus; Leuchs, Gerd
2009-01-01
We discuss the possibilities of studying in detail the dynamics of spontaneous emission of a single photon by a single atom and measuring the transient degree of squeezing by means of full solid angle fluorescence detection.
Increasing the sensitivity of future gravitational-wave detectors with double squeezed-input
Khalili, Farid Ya; Chen, Yanbei
2009-01-01
We consider improving the sensitivity of future interferometric gravitational-wave detectors by simultaneously injecting two squeezed vacuums (light), filtered through a resonant Fabry-Perot cavity, into the dark port of the interferometer.The same scheme with single squeezed vacuum was first proposed and analyzed by Corbitt et al. Here we show that the extra squeezed vacuum, together with an additional homodyne detection suggested previously by one of the authors, allows reduction of quantum noise over the entire detection band. To motivate future implementations, we take into account a realistic technical noise budget for Advanced LIGO (AdvLIGO) and numerically optimize the parameters of both the filter and the interferometer for detecting gravitational-wave signals from two important astrophysics sources, namely Neutron-Star--Neutron-Star (NSNS) binaries and Bursts. Assuming the optical loss of the 30m filter cavity to be 10ppm per bounce and 10dB squeezing injection, the corresponding quantum noise with o...
Demonstration of quadrature-squeezed surface plasmons in a gold waveguide
DEFF Research Database (Denmark)
Huck, Alexander; Smolka, Stephan; Lodahl, Peter;
2009-01-01
We report on the efficient generation, propagation and reemission of squeezed long-range surface-plasmon polaritons in a gold waveguide. Squeezed light is used to excite the nonclassical surface-plasmon polaritons, and the reemitted quantum state is fully characterized by complete quantum...... tomographic reconstruction of the density matrix. We find that the plasmon-assisted transmission of nonclassical light in metallic waveguides can be described by a beam splitter relation. This result is explained theoretically....
A fully guided-wave squeezing experiment for fiber quantum networks
Kaiser, Florian; Fedrici, Bruno; Zavatta, Alessandro; D'Auria, Virginia; Tanzilli, Sébastien
2016-01-01
International audience; Squeezed light is a fundamental resource for quantum communication. In view of its real-world applications, the realization of easy-to-operate experimental systems compatible with existing fiber networks is a crucial step. To comply with these requirements, we demonstrate the feasibility of a squeezing experiment at a telecom wavelength realized, for the first time, in an entirely guided-wave fashion. In our work, the state generation relies on waveguide non-linear opt...
Total Quantum Zeno effect and Intelligent States for a two level system in a squeezed bath
Mundarain, D; Stephany, J
2006-01-01
In this work we show that by frequent measurements of adequately chosen observables, a complete suppression of the decay in an exponentially decaying two level system interacting with a squeezed bath is obtained. The observables for which the effect is observed depend on the the squeezing parameters of the bath. The initial states which display Total Zeno Effect are intelligent states of two conjugate observables associated to the electromagnetic fluctuations of the bath.
The use of squeezed states and balanced homodyne for detecting gravitational waves
Ben-Aryeh, Y
2010-01-01
The possibility of using squeezed states and balanced homodyne detection of gravitational waves is discussed. It is shown that the quantum noise due to high laser intensities in Michelson interferometer for gravitational waves detection can be reduced by sending squeezed vacuum states to the 'dark' port of the interferometer. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting gravitational waves.
Generation of Hidden Optical-Polarization: Squeezing and Non-Classicality
Gupta, Gyaneshwar K.; Kumar, Akhilesh; Singh, Ravi S
2010-01-01
A monochromatic double-mode coherent light endowed with orthogonally polarized photons propagating collinearly is studied in Degenerate Parametric Amplification. Generation of Hidden Optical- Polarized States is shown by non-zero values of Index of Hidden Optical-Polarization. Squeezing in HOPS is demonstrated by recognizing a Squeezing function. The Non-Classical feature of HOPS is observed by 'degree of Hidden Optical-Polarization' which attains non-classical value 'greater than unity'. The...
The nonlinear squeezed one-photon states and their nonclassical properties
Institute of Scientific and Technical Information of China (English)
Wang Ji-Suo; Meng Xiang-Guo
2007-01-01
By virtue of the technique of integration within an ordered product (IWOP) of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of squeezed operators and f-analogues of squeezed one-photon states, which are quite different from ones constructed by Song and Fan (Phys. Lett. A 294 (2002) 66). Subsequently, some nonclassical properties of the states are investigated in detail.
Generation of Tunable Amplitude-Squeezed Light by Injection Locking of a Laser Diode
Institute of Scientific and Technical Information of China (English)
WANG Jun-Min; HE Ling-Xiang; ZHANG Tian-Cai; XIE Chang-De; PENG Kun-Chi
2000-01-01
Tunable amplitude squeezing around the D2 line of cesium has been experimentally accomplished at room temperature in a quantum-well laser diode with light injection from a single-mode distributed Bragg-Reflector laser diode. While the master laser frequency is tuned, amplitude squeezing of the output light from the slave laser can be maintained at about 0.9dB throughout a tunabIe range of～l.7 GHz around the cesium D2 line.
Section thickness-dependent tensile properties of squeeze cast magnesium alloy AM60
Directory of Open Access Journals (Sweden)
Xuezhi Zhang
2012-05-01
Full Text Available The development of alternative casting processes is essential for the high demand of light weight magnesium components to be used in the automotive industry, which often contain different section thicknesses. Squeeze casting with its inherent advantages has been approved for the capability of minimizing the gas porosity in magnesium alloys. For advanced engineering design of light magnesium automotive applications, it is critical to understand the effect of section thickness on mechanical properties of squeeze cast magnesium alloys. In this study, magnesium alloy AM60 with different section thicknesses of 6, 10 and 20 mm squeeze cast under an applied pressure of 30 MPa was investigated. The prepared squeeze cast AM60 specimens were tensile tested at room termperature. The results indicate that the mechanical properties including yield strength (YS, ultimate tensile strength (UTS and elongation (A decrease with an increase in section thickness of squeeze cast AM60. The microstructure analysis shows that the improvement in the tensile behavior of squeeze cast AM60 is primarily attributed to the low-gas porosity level and fine grain strucuture which result from the variation of cooling rate of different section thickness. The numerical simulation (Magmasoft? was employed to determine the solidification rates of each step, and the simulated results show that the solidification rate of the alloy decreases with an increase in the section thickness. The computed solidification rates support the experimental observation on grain structural development.
First Long-Term Application of Squeezed States of Light in a Gravitational-Wave Observatory
Grote, H; Dooley, K L; Schnabel, R; Slutsky, J; Vahlbruch, H
2013-01-01
In this work we report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German/British detector GEO600 during a period of three months from June to August 2011, where GEO600 was performing an observational run together with the French/Italian Virgo detector. Then, after a short interruption, squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum could be applied for 90.2% (205.2 days total) of the time when science-quality data was acquired with GEO\\,600. The average gain in sensitivity from squeezed vacuum application in this period was 26% (2.0dB), as measured in the frequency band from 3.7 to 4.0kHz, corresponding to a factor of two increase in observed volume of the universe. We show that the glitch-rate of the detector did not increase from squeezing application, confirming the long-term...
Output field-quadrature measurements and squeezing in ultrastrong cavity-QED
Stassi, Roberto; Savasta, Salvatore; Garziano, Luigi; Spagnolo, Bernardo; Nori, Franco
2016-12-01
We study the squeezing of output quadratures of an electro-magnetic field escaping from a resonator coupled to a general quantum system with arbitrary interaction strengths. The generalized theoretical analysis of output squeezing proposed here is valid for all the interaction regimes of cavity-quantum electrodynamics: from the weak to the strong, ultrastrong, and deep coupling regimes. For coupling rates comparable or larger then the cavity resonance frequency, the standard input-output theory for optical cavities fails to calculate the variance of output field-quadratures and predicts a non-negligible amount of output squeezing, even if the system is in its ground state. Here we show that, for arbitrary interaction strength and for general cavity-embedded quantum systems, no squeezing can be found in the output-field quadratures if the system is in its ground state. We also apply the proposed theoretical approach to study the output squeezing produced by: (i) an artificial two-level atom embedded in a coherently-excited cavity; and (ii) a cascade-type three-level system interacting with a cavity field mode. In the latter case the output squeezing arises from the virtual photons of the atom-cavity dressed states. This work extends the possibility of predicting and analyzing the results of continuous-variable optical quantum-state tomography when optical resonators interact very strongly with other quantum systems.
High-bandwidth squeezed light at 1550 nm from a compact monolithic PPKTP cavity
Ast, Stefan; Schnabel, Roman
2013-01-01
We report the generation of squeezed vacuum states of light at 1550 nm with a broadband quantum noise reduction of up to 4.8 dB ranging from 5 MHz to 1.2 GHz sideband frequency. We used a custom-designed 2.6 mm long biconvex periodically-poled potassium titanyl phosphate (PPKTP) crystal. It featured reflectively coated end surfaces, 2.26 GHz of linewidth and generated the squeezing via optical parametric amplification. Two homodyne detectors with different quantum efficiencies and bandwidths were used to characterize the non-classical noise suppression. We measured squeezing values of up to 4.8 dB from 5 to 100 MHz and up to 3 dB from 100 MHz to 1.2 GHz. The squeezed vacuum measurements were limited by detection loss. We propose an improved detection scheme to measure up to 10 dB squeezing over 1 GHz. Our results of GHz bandwidth squeezed light generation provide new prospects for high-speed quantum key distribution.
Collapse-revival of squeezing of two atoms in dissipative cavities
Institute of Scientific and Technical Information of China (English)
邹红梅; 方卯发
2016-01-01
Based on the time-convolutionless master-equation approach, we investigate the squeezing dynamics of two atoms in dissipative cavities. We find that the atomic squeezing is related to initial atomic states, atom–cavity couplings, non-Markovian effects and resonant frequencies of an atom and its cavity. The results show that a collapse–revival phenomenon will occur in the atomic squeezing and this process is accompanied by the buildup and decay of entanglement between two atoms. Enhancing the atom–cavity coupling can increase the frequency of the collapse–revival of the atomic squeezing. The stronger the non-Markovian effect is, the more obvious the collapse–revival phenomenon is. In particular, if the atom–cavity coupling or the non-Markovian effect is very strong, the atomic squeezing will tend to a stably periodic oscillation in a long time. The oscillatory frequency of the atomic squeezing is dependent on the resonant frequency of the atom and its cavity.
Phase control of squeezed vacuum states of light in gravitational wave detectors.
Dooley, K L; Schreiber, E; Vahlbruch, H; Affeldt, C; Leong, J R; Wittel, H; Grote, H
2015-04-06
Quantum noise will be the dominant noise source for the advanced laser interferometric gravitational wave detectors currently under construction. Squeezing-enhanced laser interferometers have been recently demonstrated as a viable technique to reduce quantum noise. We propose two new methods of generating an error signal for matching the longitudinal phase of squeezed vacuum states of light to the phase of the laser interferometer output field. Both provide a superior signal to the one used in previous demonstrations of squeezing applied to a gravitational-wave detector. We demonstrate that the new signals are less sensitive to misalignments and higher order modes, and result in an improved stability of the squeezing level. The new signals also offer the potential of reducing the overall rms phase noise and optical losses, each of which would contribute to achieving a higher level of squeezing. The new error signals are a pivotal development towards realizing the goal of 6 dB and more of squeezing in advanced detectors and beyond.
Fidelity of Quantum Teleportation for Single-Mode Squeezed State Light
Institute of Scientific and Technical Information of China (English)
ZHANG Jun-Xiang; XIE Chang-De; PENG Kun-Chi
2005-01-01
@@ The fidelity of quantum teleportation of a single-mode squeezed state of light is calculated based on the general theory of quantum-mechanical measurement in the Schrodinger picture. It is shown that the criterion for the nonclassical state teleportation is different from that for coherent state. F = 1/2 is no longer the rigorous boundary between classical and quantum teleportation for a squeezed state of light. When the quantum entanglement of an Einstein-Podolsky-Rosen (EPR) beam used for teleportation and the parameters of the system are given,the fidelity depends on the squeezing of the input squeezed state. The higher the squeezing is, the smaller the fidelity is, and the lower the classical limitation of fidelity is. The dependence of the optimum gain for teleporting a squeezed vacuum state upon the EPR entanglement is also calculated. The results obtained provide important references for designing experimental systems of teleporting a non-classical state and judging the quality of the teleported quantum state.
[Plato psychiatrist, Foucault platonic].
Mathov, Nicolás
2016-05-01
This work explores the links between the concepts of "soul", "law" and "word" in Plato's work, in order to highlight the importance and the centrality of the philosophical-therapeutic dimension in the Greek philosopher's thought. In that way, this work pretends to show that "contemporary" problems usually discussed within "Human Sciences" in general, and Psychiatry in particular, should confront their knowledge with Plato's work, mainly due to the profound influence his ideas have had in our Greco-Christian culture. In that sense, and with that objective, this work also explores Michel Foucault's lucid and controversial interpretation of Plato.
Hawkins, David
1985-01-01
Some questions about the relevance of the philosophy of mathematics to mathematics teaching and to early mathematics learning are discussed. Books by Lakatos, Davis and Hersh, and Kitcher are referred to extensively, with comments on a variety of instructional practices. (MNS)
DEFF Research Database (Denmark)
Tortzen, Gorm
2007-01-01
Den korte dialog 'Kleitofon' hører til den gruppe i Corpus Platonicum, der ofte anses for at være uægte. Indledningen problematiserer dette, der gives en ny ovesættelse, og der føjes en række oplysende noter til teksten. Udgivelsesdato: April...
Socrates: Platonic Political Ideal
Directory of Open Access Journals (Sweden)
Christopher P. Long
2012-01-01
Full Text Available El ensayo articula diferencias y sugiere similitudes entre las prácticas del diálogo político de Sócrates y aquellas de la escritura política de Platón. Propone, además, que tanto el diálogo socrático como la escritura platónica se orientan eróticamente hacia ideales capaces de transformar las vidas de los individuos y sus relaciones. Demuestra que en el Protágoras las prácticas del diálogo socrático se ocupan menos de Protágoras que del joven Hipócrates. En el Fedón, este ideal de Sócrates se amplía de tal manera que la misma escritura platónica aparece como capaz de hacer con los lectores lo que el diálogo de Sócrates hacía con sus interlocutores. Sócrates es el ideal político platónico. El resultado es una visión del poder de transformación política tanto del diálogo socrático como de la escritura platónica.
Platonic Relationships among Resistors
Allen, Bradley; Liu, Tongtian
2015-01-01
Calculating the effective resistance of an electrical network is a common problem in introductory physics courses. Such calculations are typically restricted to two-dimensional networks, though even such networks can become increasingly complex, leading to several studies on their properties. Furthermore, several authors have used advanced…
Directory of Open Access Journals (Sweden)
Maria Chiara Pievatolo
2015-01-01
Full Text Available Nei colloqui precedenti si erano toccate molte opinioni filosofiche sbagliate, e allora Socrate dice: “Sarebbe ben comprensibile se uno, a motivo dell’irritazione per tante cose sbagliate, per il resto della sua vita prendesse in odio ogni discorso sull’essere e lo...
Squeezed light at 1550 nm with a quantum noise reduction of 12.3 dB
Mehmet, Moritz; Eberle, Tobias; Steinlechner, Sebastian; Vahlbruch, Henning; Schnabel, Roman
2011-01-01
Continuous-wave squeezed states of light at the wavelength of 1550 nm have recently been demonstrated, but so far the obtained factors of noise suppression still lag behind today's best squeezing values demonstrated at 1064 nm. Here we report on the realization of a half-monolithic nonlinear resonator based on periodically-poled potassium titanyl phosphate which enabled the direct detection of up to 12.3 dB of squeezing at 5 MHz. Squeezing was observed down to a frequency of 2 kHz which is well within the detection band of gravitational wave interferometers. Our results suggest that a long-term stable 1550 nm squeezed light source can be realized with strong squeezing covering the entire detection band of a 3rd generation gravitational-wave detector such as the Einstein Telescope.
Energy Technology Data Exchange (ETDEWEB)
Koprulu, Kahraman G.; Aytur, Orhan
2001-06-01
We investigate the generation of amplitude-squeezed states with degenerate optical parametric amplifiers that are pumped by focused Gaussian beams. We present a model that facilitates the calculation of the squeezing level for an experimentally realistic configuration in which there is a Gaussian input signal beam that has the same confocal parameter and waist location as the Gaussian pump beam, with no restriction on the interaction length-to-confocal parameter ratio. We show that the 3-dB squeezing limit that was thought to be imposed by the Gaussian pump profile can be exceeded in the (previously uninvestigated) tight-focusing regime. We find the maximum possible amplitude squeezing in this regime to be 4.65 dB. However, it is possible to increase the squeezing level further by spatially filtering the tails of the output signal beam, resulting in squeezing levels in excess of 10 dB. {copyright} 2001 Optical Society of America
Lotfipour, H.; Shahidani, S.; Roknizadeh, R.; M. H. Naderi
2016-01-01
In this paper, we theoretically investigate the displacement and momentum fluctuations spectra of the movable mirror in a standard optomechanical system driven by a finite bandwidth squeezed vacuum light accompanying a coherent laser field. Two cases in which the squeezed vacuum is generated by degenerated and non-degenerate parametric oscillators (DPO and NDPO) are considered. We find that for the case of finite bandwidth squeezed vacuum injection, the two spectra exhibit unique features, wh...
Directory of Open Access Journals (Sweden)
José Lourenço Pereira da Silva
2011-03-01
Full Text Available The platonic ontology as known through the Phaedo and Republic is centered on the hypothesis of the intelligible Forms, that is, the platonic Socrates' belief that there are ontologically independent entities such as "the beautiful itself", "the good itself", "the equal itself" etc., of which all empirical things participate thereby receiving the properties they exhibit. Clearly, the main philosophical influences on this doctrine are pre-Socratic philosophy, the sophistic and Socrates' thought. The aim of this paper is to present which ideas or philosophical questions led Plato to postulate the Forms.
A ontologia platônica, como conhecida a partir do Fédon e da República, está centrada na hipótese das Formas inteligíveis, ou seja, a crença defendida pelo Sócrates platônico na existência de entidades ontologicamente independentes, “o belo em si”, “o bem em si”, “o igual em si”, etc., das quais as coisas empíricas participam recebendo por isso as propriedades que exibem. Notoriamente, as principais influências filosóficas dessa doutrina são a filosofia pré-socrática, a sofística e o pensamento de Sócrates. O objetivo deste artigo é mostrar que ideias ou questões filosóficas levaram Platão a postular as Formas.
The q-analogues of two-mode squeezed states constructed by virtue of the IWOP technique
Institute of Scientific and Technical Information of China (English)
Meng Xiang-Guo; Wang Ji-Suo; Li Hong-Qi
2008-01-01
The q-analogues of two-mode squeezed states are introduced by virtue of deformation quantization methods and the technique of integration within an ordered product (IWOP) of operators. Some new completeness relations about these squeezed states composed of the bra and ket which are not mutually Hermitian conjugates are obtained. Furthermore,the antibunching effects of the two-mode squeezed vacuum state S'2(r) |00> are investigated. It is found that, in different ranges of the squeezed parameter r, both modes of the state exhibit the antibunching effects and the two modes of the state are always nonclassical correlation.
Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence
Institute of Scientific and Technical Information of China (English)
Zhang Jian; Shao Bin; Zou Jian
2009-01-01
In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.
Squeeze flow of a Carreau fluid during sphere impact
Uddin, J.
2012-07-19
We present results from a combined numerical and experimental investigation into the squeeze flow induced when a solid sphere impacts onto a thin, ultra-viscous film of non-Newtonian fluid. We examine both the sphere motion through the liquid as well as the fluid flow field in the region directly beneath the sphere during approach to a solid plate. In the experiments we use silicone oil as the model fluid, which is well-described by the Carreau model. We use high-speed imaging and particle tracking to achieve flow visualisation within the film itself and derive the corresponding velocity fields. We show that the radial velocity either diverges as the gap between the sphere and the wall diminishes (Z tip → 0) or that it reaches a maximum value and then decays rapidly to zero as the sphere comes to rest at a non-zero distance (Z tip = Z min ) away from the wall. The horizontal shear rate is calculated and is responsible for significant viscosity reduction during the approach of the sphere. Our model of this flow, based on lubrication theory, is solved numerically and compared to experimental trials. We show that our model is able to correctly describe the physical features of the flow observed in the experiments.
Modeling squeezing and thermal disorder in driven oscillators
Sewran, Sashwin; Sergi, Alessandro
2014-01-01
Recently, model systems with quadratic Hamiltonians and time-dependent interactions were studied by Briegel and Popescu and by Galve et al in order to consider the possibility of both quantum refrigeration in enzymes [Proc. R. Soc. 469, 20110290 (2013)] and entanglement in the high temperature limit [Phys. Rev. Lett. 105, 180501 (2010); Phys. Rev. A 81, 062117 (2010)]. Following this line of research, we studied a model comprising two quantum harmonic oscillators driven by a time-dependent harmonic coupling. Such a system was embedded in a thermal bath represented in two different ways. In one case, the bath was composed of a finite but great number of independent harmonic oscillators with an Ohmic spectral density. In the other case, the bath was more efficiently defined in terms of a single oscillator coupled to a non-Hamiltonian thermostat. In both cases, we simulated the effect of the thermal disorder on the generation of the squeezed states in the two-oscillators relevant system. We found that, in our mo...
Squeezing the halo bispectrum: a test of bias models
Dizgah, Azadeh Moradinezhad; Noreña, Jorge; Biagetti, Matteo; Desjacques, Vincent
2015-01-01
We study the halo-matter cross bispectrum in the presence of primordial non-Gaussianity of the local type. We restrict ourselves to the squeezed limit, for which the calculation are straightforward, and perform the measurements in the initial conditions of N-body simulations, to mitigate the contamination induced by nonlinear gravitational evolution. Interestingly, the halo-matter cross bispectrum is not trivial even in this simple limit as it is strongly sensitive to the scale-dependence of the quadratic and third-order halo bias. Therefore, it can be used to test biasing prescriptions. We consider three different prescription for halo clustering: excursion set peaks (ESP), local bias and a model in which the halo bias parameters are explicitly derived from a peak-background split. In all cases, the model parameters are fully constrained with statistics other than the cross bispectrum. We measure the cross bispectrum involving one halo fluctuation field and two mass overdensity fields for various halo masses...
Squeeze flow between a sphere and a textured wall
Energy Technology Data Exchange (ETDEWEB)
Chastel, T.; Mongruel, A., E-mail: anne.mongruel@upmc.fr [Physique et Mécanique des Milieux Hétérogènes, UMR 7636 CNRS–ESPCI, Université Pierre et Marie Curie–Université Paris-Diderot, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)
2016-02-15
The motion of a millimetric sphere, translating in a viscous fluid towards a wettable textured wall, is investigated experimentally. The textures consist of square arrays of cylindrical or square micro-pillars, the height, width, and spacing of which are varied, keeping the periodicity small compared to the sphere radius. An interferometric device is used to measure the sphere vertical displacement, for distances between the sphere and the base of the pillars smaller than 0.1 sphere radius, and with a resolution of 200 nm. At a given distance from the top of the pillars, the sphere velocity is found to be significantly larger than the corresponding velocity for a smooth solid wall. A squeeze flow model of two adjacent fluid layers is developed in the lubrication approximation, one fluid layer having an effective viscosity that reflects the viscous dissipation through the array of pillars. The pressure field in the gap between the sphere and the textured surface is then used to obtain the drag force on the sphere and hence its velocity. Adjustment of the model to the velocity measurements yields the effective viscosity for a given texture. Finally, a correlation between the effective viscosity and the geometry of the pillar array is proposed.
Dinesh Kumar, K K; Bhardwaj, Neerja; Yaddanapudi, Sandhya
2017-01-01
It is not known whether trapezius squeeze test (TPZ) is a better clinical test than jaw thrust (JT) to assess laryngeal mask airway (LMA) insertion conditions in children under sevoflurane anesthesia. After the Institutional Ethics Committee approval and written informed parental consent, 124 American Society of Anesthesiologists I and II children of 2-8 years of age undergoing minor surgical procedures were randomized into TPZ and JT groups. The children were induced with 8% sevoflurane in oxygen at a fresh gas flow of 4 L/min. TPZ or JT was performed after 1 min of start of sevoflurane and then every 20 s till the test was negative, when end-tidal (ET) sevoflurane concentration was noted. Classic LMA of requisite size was inserted by a blinded anesthetist and conditions at the insertion of LMA, insertion time, and the number of attempts of LMA insertion were recorded. The mean LMA insertion time was significantly longer (P < 0.001) for TPZ (145 ± 28.7 sec) compared to JT group (111.8 ± 31.0 sec). ET sevoflurane concentration at the time of LMA insertion was comparable in the two groups. LMA insertion conditions were similar in the two groups. There was no difference between the two groups regarding total number of attempts of LMA insertion. Heart rate (HR) decreased in both groups after LMA insertion (P < 0.001) but TPZ group had significantly lower HR compared with the JT group up to 5 min after LMA insertion (P = 0.03). Both JT and TPZ are equivalent clinical indicators in predicting the optimal conditions of LMA insertion in spontaneously breathing children; however, it takes a longer time to achieve a negative TPZ squeeze test.
Microstructure and Tensile Properties of Wrought Al Alloy 5052 Produced by Rheo-Squeeze Casting
Lü, Shulin; Wu, Shusen; Wan, Li; An, Ping
2013-06-01
The semisolid slurry of wrought Al alloy 5052 was prepared by the indirect ultrasonic vibration (IUV) method, in which the horn was vibrated under the outside of the metallic cup containing molten alloy, and then shaped by direct squeeze casting (SC). Spherical primary α-Al particles were uniformly dispersed in the matrix and presented a bimodal distribution of grain sizes. The effects of rheo-squeeze casting (RSC) parameters such as squeeze pressure and solid fraction on the microstructure and tensile properties of the semisolid alloy were investigated. The results indicate that average diameters of the primary α-Al particles decreased with the increase of squeeze pressure, while the tensile properties of the alloy increased. With the increase of solid fraction, the tensile strength increased first and then decreased, but the elongation decreased continuously. The best tensile properties were achieved when the slurry with a solid fraction of 0.17 solidified under 100 MPa. Compared to conventional squeeze casting, RSC process can offer the 5052 alloy better tensile strength and elongation, which were improved by 9.7 pct and 42.4 pct, respectively.
dell'Anno, Fabio; de Siena, Silvio; Illuminati, Fabrizio
2004-03-01
Extending the scheme developed for a single mode of the electromagnetic field in the preceding paper [F. Dell’Anno, S. De Siena, and F. Illuminati, Phys. Rev. A 69, 033812 (2004)], we introduce two-mode nonlinear canonical transformations depending on two heterodyne mixing angles. They are defined in terms of Hermitian nonlinear functions that realize heterodyne superpositions of conjugate quadratures of bipartite systems. The canonical transformations diagonalize a class of Hamiltonians describing nondegenerate and degenerate multiphoton processes. We determine the coherent states associated with the canonical transformations, which generalize the nondegenerate two-photon squeezed states. Such heterodyne multiphoton squeezed states are defined as the simultaneous eigenstates of the transformed, coupled annihilation operators. They are generated by nonlinear unitary evolutions acting on two-mode squeezed states. They are non-Gaussian, highly nonclassical, entangled states. For a quadratic nonlinearity the heterodyne multiphoton squeezed states define two-mode cubic phase states. The statistical properties of these states can be widely adjusted by tuning the heterodyne mixing angles, the phases of the nonlinear couplings, as well as the strength of the nonlinearity. For quadratic nonlinearity, we study the higher-order contributions to the susceptibility in nonlinear media and we suggest possible experimental realizations of multiphoton conversion processes generating the cubic-phase heterodyne squeezed states.
a Scaling Law for Amplitude-Squared Squeezing in Kerr Effect
Prakash, Hari; Kumar, Pankaj
We study amplitude-squared squeezing in interaction of coherent light with a nonlinear Kerr medium modelled as an anharmonic oscillator with interaction Hamiltonian H = ½ λ a+2 a2, where λ is proportional to χ(3) of the nonlinear medium and a is annihilation operator for the interacting field. We find the squeezing parameter S ( τ, r) in terms of a dimensionless interaction time τ = λ t and Kerr parameter r, which is product of, τ and the average number of photons and obtain almost complete amplitude-squared squeezing (i.e., S ≈ 0) for very small interaction time and very large intensity of the interacting light. We optimize squeezing parameter S ( τ, r) by an analytic estimation assuming high intensity of the interacting light and realistic values of Kerr nonlinearity following J.Bajer et al. [Czech. J. Phy. 52, 1313 (2002)] and obtain a scaling law for optimal amplitude-squared squeezing with minimum value Smin, at r = rmin for a given τ. The validity of the scaling law is checked numerically and analytically in the region of realistic values of Kerr nonlinearity and intensity of the interacting light.
Institute of Scientific and Technical Information of China (English)
王昇
2013-01-01
柏拉图的美学思想深受其所处时代及其自身哲学思想的影响。柏拉图对于美的本质、艺术的教育功能都有比较深刻的论述。其思想的精华之处至今对于我国的美育、艺术教育仍有重要的借鉴意义。%Platon's aesthetic thought is deeply influenced by the times and his own philosophy. Platon had deeply discussed the nature of beauty and the educational function of art. The essence of his thought is still of important reference meanings for the pre-cent aesthetic education and art education in our country.
Numerical Simulation of Squeezing Failure in a Coal Mine Roadway due to Mining-Induced Stresses
Gao, Fuqiang; Stead, Doug; Kang, Hongpu
2015-07-01
Squeezing failure is a common failure mechanism experienced in underground coal mine roadways due mainly to mining-induced stresses, which are much higher than the strength of rock mass surrounding an entry. In this study, numerical simulation was carried out to investigate the mechanisms of roadway squeezing using a novel UDEC Trigon approach. A numerical roadway model was created based on a case study at the Zhangcun coal mine in China. Coal extraction using the longwall mining method was simulated in the model with calculation of the mining-induced stresses. The process of roadway squeezing under severe mining-induced stresses was realistically captured in the model. Deformation phenomena observed in field, including roof sag, wall convexity and failed rock bolts are realistically produced in the UDEC Trigon model.
The precision and torque production of common hip adductor squeeze tests used in elite football
DEFF Research Database (Denmark)
Light, N; Thorborg, K
2016-01-01
OBJECTIVES: Decreased hip adductor strength is a known risk factor for groin injury in footballers, with clinicians testing adductor strength in various positions and using different protocols. Understanding how reliable and how much torque different adductor squeeze tests produce will facilitate...... choosing the most appropriate method for future testing. In this study, the reliability and torque production of three common adductor squeeze tests were investigated. DESIGN: Test-retest reliability and cross-sectional comparison. METHODS: Twenty elite level footballers (16-33 years) without previous...... or current groin pain were recruited. Relative and absolute test-retest reliability, and torque production of three adductor squeeze tests (long-lever in abduction, short-lever in adduction and short-lever in abduction/external rotation) were investigated. Each participant performed a series of isometric...
Ma, Yong-Hong; Zhang, Xue-Feng; Song, Jie; Wu, E.
2016-06-01
As the quantum states of nitrogen vacancy (NV) center can be coherently manipulated and obtained at room temperature, it is important to generate steady-state spin squeezing in spin qubits associated with NV impurities in diamond. With this task we consider a new type of a hybrid magneto-nano-electromechanical resonator, the functionality of which is based on a magnetic-field induced deflection of an appropriate cantilever that oscillates between NV spins in diamond. We show that there is bistability and spin squeezing state due to the presence of the microwave field, despite the damping from mechanical damping. Moreover, we find that bistability and spin squeezing can be controlled by the microwave field and the parameter Vz. Our scheme may have the potential application on spin clocks, magnetometers, and other measurements based on spin-spin system in diamond nanostructures.
Curvilinear Squeeze Film Bearing with Porous Wall Lubricated by a Rabinowitsch Fluid
Walicka, A.; Walicki, E.; Jurczak, P.; Falicki, J.
2017-05-01
The present theoretical analysis is to investigate the effect of non-Newtonian lubricant modelled by a Rabinowitsch fluid on the performance of a curvilinear squeeze film bearing with one porous wall. The equations of motion of a Rabinowitsch fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation the modified Reynolds equation is obtained. The analytical solution of this equation for the case of a squeeze film bearing is presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing and spherical bearing with a squeeze film are considered as numerical examples.
Scalable Spin Squeezing for Quantum-Enhanced Magnetometry with Bose-Einstein Condensates
Muessel, W.; Strobel, H.; Linnemann, D.; Hume, D. B.; Oberthaler, M. K.
2014-09-01
A major challenge in quantum metrology is the generation of entangled states with a macroscopic atom number. Here, we demonstrate experimentally that atomic squeezing generated via nonlinear dynamics in Bose-Einstein condensates, combined with suitable trap geometries, allows scaling to large ensemble sizes. We achieve a suppression of fluctuations by 5.3(5) dB for 12 300 particles, from which we infer that similar squeezing can be obtained for more than 107 atoms. With this resource, we demonstrate quantum-enhanced magnetometry by swapping the squeezed state to magnetically sensitive hyperfine levels that have negligible nonlinearity. We find a quantum-enhanced single-shot sensitivity of 310(47) pT for static magnetic fields in a probe volume as small as 90 μm3.
Squeezed bispectrum in the δ N formalism: local observer effect in field space
Tada, Yuichiro; Vennin, Vincent
2017-02-01
The prospects of future galaxy surveys for non-Gaussianity measurements call for the development of robust techniques for computing the bispectrum of primordial cosmological perturbations. In this paper, we propose a novel approach to the calculation of the squeezed bispectrum in multiple-field inflation. With use of the δ N formalism, our framework sheds new light on the recently pointed out difference between the squeezed bispectrum for global observers and that for local observers, while allowing one to calculate both. For local observers in particular, the squeezed bispectrum is found to vanish in single-field inflation. Furthermore, our framework allows one to go beyond the near-equilateral ("small hierarchy") limit, and to automatically include intrinsic non-Gaussianities that do not need to be calculated separately. The explicit computational programme of our method is given and illustrated with a few examples.
Statistical Properties of Photon-Added Two-Mode Squeezed Coherent States
Wang, Zhen; Li, Heng-Mei; Yuan, Hong-Chun; Wan, Zhi-Long; Meng, Xiang-Guo
2016-12-01
The nonclassical and non-Gaussian quantum states—photon-added two-mode squeezed coherent states have been theoretically introduced by adding multiple photons to each mode of the two-mode squeezed coherent states. Starting from the new expression of two-mode squeezing operator in entangled states representation, the normalization factor is obtained, which is directly related to bivariate Hermite polynomials. The sub-Poissonian photon statistics, cross-correlation between two modes, partial negative Wigner function are observed, which fully reflect the nonclassicality of the target states. The negative Wigner function often display non-Gaussian distribution meanwhile. The investigations may provide experimentalists with some better references in quantum engineering.
The Effect of Spin Squeezing on the Entanglement Entropy of Kicked Tops
Directory of Open Access Journals (Sweden)
Ernest Teng Siang Ong
2016-04-01
Full Text Available In this paper, we investigate the effects of spin squeezing on two-coupled quantum kicked tops, which have been previously shown to exhibit a quantum signature of chaos in terms of entanglement dynamics. Our results show that initial spin squeezing can lead to an enhancement in both the entanglement rate and the asymptotic entanglement for kicked tops when the initial state resides in the regular islands within a mixed classical phase space. On the other hand, we found a reduction in these two quantities if we were to choose the initial state deep inside the chaotic sea. More importantly, we have uncovered that an application of periodic spin squeezing can yield the maximum attainable entanglement entropy, albeit this is achieved at a reduced entanglement rate.
Steady-state entanglement of cavity arrays in finite-bandwidth squeezed reservoirs
Zippilli, Stefano
2014-01-01
When two chains of quantum systems are driven at their ends by a two-mode squeezed reservoir, they approach a steady state characterized by the formation of many entangled pairs. Each pair is made of one element of the first and one of the second chain. This effect has been already predicted under the assumption of broadband squeezing. Here we investigate the situation of finite-bandwidth reservoirs. This is done by modeling the driving bath as the output field of a non-degenerate parametric oscillator. The resulting non-Markovian dynamics is studied within the theoretical framework of cascade open quantum systems. It is shown that the formation of pair-entangled structures occurs as long as the normal-mode splitting of the arrays does not overcome the squeezing bandwidth of the reservoir.
Phase space interference and the WKB approximation for squeezed number states
Mundarain, D F
2003-01-01
Squeezed number states for a single mode Hamiltonian are investigated from two complementary points of view. Firstly the more relevant features of their photon distribution are discussed using the WKB wave functions. In particular the oscillations of the distribution and the parity behavior are derived and compared with the exact results. The accuracy is verified and it is shown that for high photon number it fails to reproduce the true distribution. This is contrasted with the fact that for moderate squeezing the WKB approximation gives the analytical justification to the interpretation of the oscillations as the result of the interference of areas with definite phases in phase space. It is shown with a computation at high squeezing using a modified prescription for the phase space representation which is based on Wigner-Cohen distributions that the failure of the WKB approximation does not invalidate the area overlap picture.
Pressure Distribution in a Porous Squeeze Film Bearing Lubricated with a Herschel-Bulkley Fluid
Directory of Open Access Journals (Sweden)
Walicka A.
2016-12-01
Full Text Available The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated with a lubricant being a viscoplastic fluid of a Herschel-Bulkley type is considered. After general considerations on the flow of the viscoplastic fluid (lubricant in a bearing clearance and in a porous layer the modified Reynolds equation for the curvilinear squeeze film bearing with a Herschel-Bulkley lubricant is given. The solution of this equation is obtained by a method of successive approximation. As a result one obtains a formula expressing the pressure distribution. The example of squeeze films in a step bearing (modeled by two parallel disks is discussed in detail.
Analytic and laser vibrometry study of squeeze film damping of MEMS cantilevers
Vignola, Joseph F.; Judge, John A.; Lawrence, Eric; Jarzynski, Jacek; Houston, Brian
2006-06-01
This study compares theoretical predictions to experimental measurements of squeeze film damping of MEMS cantilevers in a fluid environment. A series of MEMS cantilevers were fabricated on a silicon wafer. Each of the silicon beams was 2 μm thick and 18 μm wide. The lengths range from 100 to 800 μm and the air-filled gap between the cantilever and the substrate was 6 μm. An analytic model for squeeze film damping was used to predict the corresponding quality factor Q squeeze film (the ratio of the mechanical energy stored in the oscillator to the energy dissipated per cycle) for these cantilevers. The results from the modeling are compared to experimental results obtained using a Polytec MSA-400 Micro System Analyzer.
A high-fidelity photon gun: intensity-squeezed light from a single molecule
Chu, Xiao-Liu; Sandoghdar, Vahid
2016-01-01
A two-level atom cannot emit more than one photon at a time. As early as the 1980s, this quantum feature was identified as a gateway to "single-photon sources", where a regular excitation sequence would create a stream of light particles with photon number fluctuations below the shot noise. Such an intensity squeezed beam of light would be desirable for a range of applications such as quantum imaging, sensing, enhanced precision measurements and information processing. However, experimental realizations of these sources have been hindered by large losses caused by low photon collection efficiencies and photophysical shortcomings. By using a planar metallo-dielectric antenna applied to an organic molecule, we demonstrate the most regular stream of single photons reported to date. Measured intensity fluctuations reveal 2.2 dB squeezing limited by our detection efficiency, equivalent to 6.2 dB intensity squeezing right after the antenna.
Phase transition to spatial Bloch-like oscillation in squeezed photonic lattices
Nezhad, M Khazaei; Golshani, M; Mahdavi, S M; Langari, A
2013-01-01
We propose an exactly solvable waveguide lattice incorporating inhomogeneous coupling coefficient. This structure provides a classical analogue to the squeezed number and squeezed coherent intensity distribution in quantum optics where the propagation length plays the role of squeezed amplitude. The intensity pattern is obtained in a closed form for an arbitrary distribution of the initial beam profile. We have also investigated the phase transition to the spatial Bloch-like oscillations by adding a linear gradient to the propagation constant of each waveguides ($ \\alpha $). Our analytical results show that the Bloch-like oscillations appear above a critical value for the linear gradient of propagation constant ($ \\alpha > \\alpha_{c} $). The phase transition (in the propagation properties of the waveguide) is a result of competition between discrete and Bragg diffraction. Moreover, the light intensity decay algebraically along each waveguide at the critical point while it falls off exponentially below the cri...
Perina, Jan
2013-01-01
Quantum pulsed second-subharmonic generation in a planar waveguide with a small periodic corrugation at the surface is studied. Back-scattering of the interacting fields on the corrugation enhances the nonlinear interaction giving larger values of squeezing. The problem of back-scattering is treated by perturbation theory, using the Fourier transform for non-dispersion propagation, and by numerical approach in the general case. Optimum spectral modes for squeezed-light generation are found using the Bloch-Messiah reduction. Improvement in squeezing and increase of numbers of generated photons are quantified for the corrugation resonating with the fundamental and second-subharmonic field. Splitting of the generated pulse by the corrugation is predicted.
Demonstrating an additional law of relativistic velocities based on squeezed light
Institute of Scientific and Technical Information of China (English)
Yang Da-Bao; Li Yan; Zhang Fu-Lin; Chen Jing-Ling
2012-01-01
The special relativity is the foundation for many branches of modern physics,of which the theoretical results are far beyond our daily experience and hard to realized in kinematic experiments.However,its outcomes could be demonstrated by making use of the convenient substitute,i.e.,the squeezed light in the present paper.The squeezed light is very important in the field of quantum optics,and the corresponding transformation can be regarded as the coherent state of SU(1,1).In this paper,the connection between the squeezed operator and the Lorentz boost is built under certain conditions.Furthermore,the additional law of relativistic velocities and the angle of the Wigner rotation are deduced as well.
Experimental investigation of time-dependent cavitation in an oscillatory squeeze film
Institute of Scientific and Technical Information of China (English)
CHEN Xiaoyang; SUN Meili; WANG Wen; D.C.SUN; ZHANG Zhiming; WANG Xiaojing
2004-01-01
The occurrence of time-dependent cavitation and tensile stress in an oscillatory oil squeeze film were investigated experimentally. The test apparatus was a simple thrust bearing consisting of two parallel circular plates separated by a thin viscous oil film. During the test, one plate was at rest while the other (transparent) oscillated in a direction normal to its surface. This test configuration was chosen to avoid the rotational motion and complicated geometry of a squeeze film journal bearing. The frequency of oscillation was in the range of 5 to 50 Hz and was controlled by an electro-magnetic exciter. The process of cavity formation and its subsequent development was recorded by a high-speed video camera. Concomitant pressure in the oil film was measured both within and without the cavitation region. It was found that both tensile stress and cavities existed in a squeeze film under certain working conditions.
Squeezed Bispectrum in the $\\delta N$ Formalism: Local Observer Effect in Field Space
Tada, Yuichiro
2016-01-01
The prospects of future galaxy surveys for non-Gaussianity measurements call for the development of robust techniques for computing the bispectrum of primordial cosmological perturbations. In this paper, we propose a novel approach to the calculation of the squeezed bispectrum in multiple-field inflation. With use of the $\\delta N$ formalism, our framework sheds new light on the recently pointed out difference between the squeezed bispectrum for global observers and that for local observers, while allowing one to calculate both. For local observers in particular, the squeezed bispectrum is found to vanish in single-field inflation. Furthermore, our framework allows one to go beyond the near-equilateral ("small hierarchy") limit, and to automatically include intrinsic non-Gaussianities that do not need to be calculated separately. The explicit computational programme of our method is given and illustrated with a few examples.
Squeezing of thermal fluctuations in four-wave mixing in a \\Lambda-scheme
Erukhimova, Maria
2016-01-01
We theoretically investigate the mechanism of two-mode quadrature squeezing in regime of four-wave mixing in a \\Lambda-scheme of three-level atoms embedded in a thermal reservoir. We demonstrate that the process of nonlinear transfer of noise from the low frequency of ground state splitting to the optical frequency drastically modifies the condition of effective two-mode squeezing. The damage factor is significant if number of thermal photons at the low frequency is high and the role of inelastic processes in ground state coherence decay is not negligible. We found the optimal conditions for squeezing, in particular optimal density-length product of active medium depending on the relaxation parameters and drive intensity.
Effect of oscillation mode on the free-molecule squeeze-film air damping
Gang Hong,
2010-01-01
A 3D Monte Carlo (MC) simulation approach is developed and employed to study the effect of the oscillation mode on the squeeze-film air damping in the free-molecule regime. By tracking individual gas molecule\\'s motion and its interaction with the resonator, the MC approach is by far the most accurate modeling approach for the modeling of squeeze-film damping in the free-molecule regime. The accuracy of this approach is demonstrated on several cases in which either analytical solutions or experimental measurements are available. It has been found that unlike the case when resonators oscillate in an unbounded domain, squeeze film damping is very sensitive to the mode shape, which implies that some of the existing modeling approaches based on rigid-resonator assumption may not be accurate when applied to model resonators oscillating at their deformed shape. ©2010 IEEE.
Audio-Band Frequency-Dependent Squeezing for Gravitational-Wave Detectors.
Oelker, Eric; Isogai, Tomoki; Miller, John; Tse, Maggie; Barsotti, Lisa; Mavalvala, Nergis; Evans, Matthew
2016-01-29
Quantum vacuum fluctuations impose strict limits on precision displacement measurements, those of interferometric gravitational-wave detectors among them. Introducing squeezed states into an interferometer's readout port can improve the sensitivity of the instrument, leading to richer astrophysical observations. However, optomechanical interactions dictate that the vacuum's squeezed quadrature must rotate by 90° around 50 Hz. Here we use a 2-m-long, high-finesse optical resonator to produce frequency-dependent rotation around 1.2 kHz. This demonstration of audio-band frequency-dependent squeezing uses technology and methods that are scalable to the required rotation frequency and validates previously developed theoretical models, heralding application of the technique in future gravitational-wave detectors.
Strong quantum squeezing near the pull-in instability of a nonlinear beam
Passian, Ali; Siopsis, George
2016-08-01
Microscopic silicon-based suspended mechanical oscillators, constituting an extremely sensitive force probe, transducer, and actuator, are being increasingly employed in many developing microscopies, spectroscopies, and emerging optomechanical and chem-bio sensors. We predict a significant squeezing in the quantum state of motion of an oscillator constrained as a beam and subject to an electrically induced nonlinearity. By taking into account the quantum noise, the underlying nonlinear dynamics is investigated in both the transient and stationary regimes of the driving force leading to the finding that strongly squeezed states are accessible in the vicinity of the pull-in instability of the oscillator. We discuss a possible application of this strong quantum squeezing as an optomechanical method for detecting broad-spectrum single or low-count photons, and further suggest other novel sensing actions.
Squeezing properties of a trapped ion in the running-wave laser beyond the Lamb-Dicke limit
Institute of Scientific and Technical Information of China (English)
Pan Chang-Ning; Fang Mao-Fa; Zheng Xiao-Juan; Hu Yao-Hua
2007-01-01
Beyond the Lamb-Dicke limit, this paper investigates the squeezing properties of the trapped ion in the travelling-wave laser. It shows that the squeezing properties of the trapped ion in the travelling-wave laser are strongly affected by the sideband number k, the Lamb- Dicke parameterηand the initial average phonon number.
Prediction of Secondary Dendrite Arm Spacing in Squeeze Casting Using Fuzzy Logic Based Approaches
Directory of Open Access Journals (Sweden)
Patel M.G.C.
2015-03-01
Full Text Available The quality of the squeeze castings is significantly affected by secondary dendrite arm spacing, which is influenced by squeeze cast input parameters. The relationships of secondary dendrite arm spacing with the input parameters, namely time delay, pressure duration, squeeze pressure, pouring and die temperatures are complex in nature. The present research work focuses on the development of input-output relationships using fuzzy logic approach. In fuzzy logic approach, squeeze cast process variables are expressed as a function of input parameters and secondary dendrite arm spacing is expressed as an output parameter. It is important to note that two fuzzy logic based approaches have been developed for the said problem. The first approach deals with the manually constructed mamdani based fuzzy system and the second approach deals with automatic evolution of the Takagi and Sugeno’s fuzzy system. It is important to note that the performance of the developed models is tested for both linear and non-linear type membership functions. In addition the developed models were compared with the ten test cases which are different from those of training data. The developed fuzzy systems eliminates the need of a number of trials in selection of most influential squeeze cast process parameters. This will reduce time and cost of trial experimentations. The results showed that, all the developed models can be effectively used for making prediction. Further, the present research work will help foundrymen to select parameters in squeeze casting to obtain the desired quality casting without much of time and resource consuming.
Entropy squeezing of the field interacting with a nearly degenerate V-type three-level atom
Institute of Scientific and Technical Information of China (English)
Zhou Qing-Chun; Zhu Shi-Ning
2005-01-01
The position- and momentum-entopic squeezing properties of the optical field in the system of a nearly degenerate three-level atom interacting with a single-mode field are investigated. Calculation results indicate that when the field is initially in the vacuum state, it may lead to squeezing of the position entropy or the momentum entropy of the field if the atom is prepared properly. The effects of initial atomic state and the splitting of the excited levels of the atom on field entropies are discussed in this case. When the initial field is in a coherent state, we find that position-entropy squeezing of the field is present even if the atom is prepared in the ground state. By comparing the variance squeezing and entropy squeezing of the field we confirm that entropy is more sensitive than variance in measuring quantum fluctuations.
Institute of Scientific and Technical Information of China (English)
XIANG Shao-Hua; SONG Ke-Hui; WEN Wei; SHI Zhen-Gang
2011-01-01
We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the characteristic function method. We analyze the entanglement dynamics of two-mode squeezed thermal state in this model and show that its entanglement dynamics is strongly determined by the two-mode squeezing parameter and the purity. In particular, we find that two-mode squeezed thermal state with the squeezing parameter r ≤ -(1/2) In (V)u is extremely fragile and almost does not survive in a common vacuum environment. We investigate the time evolution of nonlocality for two-mode squeezed thermal state in such an environment. It is found that the evolved state loses its nonlocality in the beginning of the evolution, but after a time, the revival of nonlocality can occur.
Zhang, Yu-Yu
2016-12-01
Generalized squeezing rotating-wave approximation (GSRWA) is proposed by employing both the displacement and the squeezing transformations. A solvable Hamiltonian is reformulated in the same form as the ordinary RWA ones. For a qubit coupled to oscillators experiment, a well-defined Schrödinger-cat-like entangled state is given by the displaced-squeezed oscillator state instead of the original displaced state. For the isotropic Rabi case, the mean photon number and the ground-state energy are expressed analytically with additional squeezing terms, exhibiting a substantial improvement of the GSRWA. And the ground-state energy in the anisotropic Rabi model confirms the effectiveness of the GSRWA. Due to the squeezing effect, the GSRWA improves the previous methods only with the displacement transformation in a wide range of coupling strengths even for large atom frequency.
Energy Technology Data Exchange (ETDEWEB)
Zhu Jiuyun (Department of Physics, Hunan Normal University, Hunan 410006 (China)); Kuang Leman (Theoretical Physics Division, Nankai Institute of Mathematics, Tianjin 300071 (China) Department of Physics and Institute of Physics, Hunan Normal University, Hunan 410081 (China))
1994-10-03
The even and odd coherent states (CSs) of a finite-dimensional Hilbert space harmonic oscillator (FDHSHO) are constructed and some properties of these states are studied. Their quadrature squeezing and amplitude-squared squeezing are investigated in detail. It is shown that, while the squeezing behaviour of the even and odd CSs of the FDHSHO approaches that of the even and odd CSs of the usual harmonic oscillator as the dimension of the Hilbert space tends to infinity, this behaviour is nontrivally different if the dimension of the Hilbert space is finite. In the latter case, it is found that the even and odd CSs exhibit both amplitude-squared squeezing and quadrature squeezing. ((orig.))
Study on the squeezing effect of open-ended pipe piles
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
During the installation of a pipe pile,the soil around the pile will be squeezed out. This paper deals with this squeezing effect of open-ended pipe piles using the cylindrical cavity expansion theory. The characteristics of soil with different tension and compression moduli and dilation are involved by applying the elastic theory with different moduli and logarithmic strain. The closed-form solutions of the radius of the plastic region,the displacement of the boundary between the plastic region and the ela...
SQUEEZING EFFECT OF RAIL LOADED BY SEMI-SLEEPERS HAVING L-SHAPED CROSS-SECTION
Directory of Open Access Journals (Sweden)
V. N. Sukhodoev
2015-01-01
Full Text Available The paper considers a problem on introduction of a conception and regularities of “squeezing effect of a rail loaded non centrally by semi-sleepers having L-shaped cross-section” exemplified by belt-type tramway. Its advantages are ensured by doubled non centrally loaded foundations these are semi-sleepers. Semi-sleeper of L-shape cross-section is a lever of L-shape form, transforming a vertical load into horizontal ones and foundation squeezing. Properties of two semi-sleepers being doubled, orientated to each other and non centrally loaded have been used in order to create a positive effect. A horizontal force creates squeezing and it is revealed as a component of a vertical load during displacements which functionally depend on foundation squeezing. These dependences demonstrate that strength and deformation properties of earth foundation of vertical direction are used for creation of horizontal properties of sleeper vertical shoulder.The paper studies mechanics pertaining to a squeezing effect of a rail loaded by semi-sleepers having L-shaped cross-section. It has been established that the rail squeezing effect results from squeezing process executed in two mutually perpendicular directions (reduction of cross-sectional area by load of a rail wheel with spacers if they are set inside of a sleeper-mechanism on an elastic foundation.Methodology for calculation of parameters on the rail reduction effect is considered as a tool for handling of applied problems on belt-type tramways. Results of the proposed rail reduction effect in problem statement for elastic conditions, with unchanged cross-sectional dimension of a rail line and introduction of correction ratio coefficients due to new initial load data have recommended for practical application as reliable values.The paper has revealed a proportional dependence of the rail reduction effect according to strength on the resultant value of reaction pressure, eccentricity difference of the
Many-body quantum dynamics of polarisation squeezing in optical fibre
Corney, J F; Heersink, J; Josse, V; Leuchs, G; Andersen, U L
2006-01-01
We report new experiments that test quantum dynamical predictions of polarization squeezing for ultrashort photonic pulses in a birefringent fibre, including all relevant dissipative effects. This exponentially complex many-body problem is solved by means of a stochastic phase-space method. The squeezing is calculated and compared to experimental data, resulting in excellent quantitative agreement. From the simulations, we identify the physical limits to quantum noise reduction in optical fibres. The research represents a significant experimental test of first-principles time-domain quantum dynamics in a one-dimensional interacting Bose gas coupled to dissipative reservoirs.
Multipartite State Representations in Multi-mode Fock Space and Their Squeezing Transformations
Institute of Scientific and Technical Information of China (English)
YUAN Hong-Chun; LI Heng-Mei; QI Kai-Guo
2007-01-01
We present the continuous state vector of the total coordinate of multi-particle and the state vector of their total momentum, respectively, which possess completeness relation in multi-mode Fock space by virtue of the integration within an order product (IWOP) technique. We also calculate the transition from classical transformation of variables in the states to quantum unitary operator, deduce a new multi-mode squeezing operator, and discuss its squeezing effect. In progress, it indicates that the IWOP technique provides a convenient way to construct new representation in quantum mechanics.
Wenger, Jérôme; Tualle-Brouri, Rosa; Grangier, Philippe
2004-06-01
A new scheme is described for the generation of pulsed squeezed light by use of femtosecond pulses that have been parametrically deamplified through a single pass in a thin (100-microm) potassium niobate crystal with a significant deamplification of approximately -3 dB. The quantum noise of each pulse is registered in the time domain by single-shot homodyne detection operated with femtosecond pulses; the best squeezed quadrature variance was 1.87 dB below the shot-noise level. Such a scheme provides a basic resource for time-resolved quantum communication protocols.
Time-resolved detection of relative intensity squeezed nanosecond pulses in a 87Rb vapor
Agha, Imad H; Messin, Gaetan; Grangier, Philippe
2010-01-01
We present experimental studies on the generation and detection of pulsed, relative-intensity squeezed light in a warm rubidium vapor. The noise correlations between a pulsed probe beam and its conjugate -generated through nearly-degenerate four-wave mixing in a double-lambda system- are studied via time-resolved balanced detection. We observe -0.96 dB of time-resolved relative intensity squeezing with 50 nanosecond pulses at 1 MHz repetition rate. (-1.34 dB corrected for loss).
Wenger, J; Grangier, P
2004-01-01
A new scheme is described for pulsed squeezed light generation using femtosecond pulses parametrically deamplified through a single pass in a thin (0.1mm) potassium niobate KNbO3 crystal, with a significant deamplification of about -3dB. The quantum noise of each individual pulse is registered in the time domain using a single-shot homodyne detection operated with femtosecond pulses and the best squeezed quadrature variance was measured to be 1.87 dB below the shot noise level. Such a scheme provides the basic ressource for time-resolved quantum communication protocols.
Time-resolved detection of relative intensity squeezed nanosecond pulses in a Rb87 vapor
Agha, Imad H; Glorieux, Quentin; Coudreau, Thomas; Grangier, Philippe; Messin, Gaetan
2011-01-01
We present theoretical and experimental results on the generation and detection of pulsed, relative-intensity squeezed light in a hot Rb87 vapor. The intensity noise correlations between a pulsed probe beam and its conjugate, generated through nearly-degenerate four-wave mixing in a double-lambda system, are studied numerically and measured experimentally via time-resolved balanced detection. We predict and observe about -1 dB of time-resolved relative intensity squeezing with 50 nanosecond pulses at 1 MHz repetition rate. (-1.34 dB corrected for loss).
Zhang, Zhifeng; Drapaca, Corina
2016-11-01
Ischemic stroke accounts for about 87 percent of all stroke cases. In these cases, models of squeezing a droplet through a smaller constriction channel can help better understand the pathology and capillary restoring after a Stroke. In the present research, we analytical expressed the minimum impulse of squeezing a droplet through a circular channel as well as its critical velocity. By comparison with a previously defined critical velocity, we find the difference between these two. Applications of this research in the understanding of ischemic stroke are also discussed. Zhifeng Zhang thanks the support of Robert A. Sebrosky Graduate Fellowship in Engineering Science and Mechanics, the Pennsylvania State University.
Khan, Ghulam Abbas; Li, Changbiao; Raza, Faizan; Ahmed, Noor; Mahesar, Abdul Rasheed; Ahmed, Irfan; Zhang, Yanpeng
2017-06-14
We realized an optical transistor and router utilizing multi-order fluorescence and spontaneous parametric four-wave mixing. Specifically, the optical routing action was derived from the results of splitting in the intensity signal due to a dressing effect, whereas the transistor as a switch and amplifier was realized by a switching correlation and squeezing via a nonlinear phase. A substantial enhancement of the optical contrast was observed for switching applications using correlation and squeezing contrary to the intensity signal. Moreover, the controlling parameters were also configured to devise a control mechanism for the optical transistor and router.
Entangling different degrees of freedom by quadrature squeezing cylindrically polarized modes
DEFF Research Database (Denmark)
Gabriel, C.; Aiello, A.; Zhong, W.
2011-01-01
for intense beams of light by exploiting the properties of cylindrically polarized modes. We show that already in a classical picture the spatial and polarization field variables of these modes cannot be factorized. Theoretically it is proven that by quadrature squeezing cylindrically polarized modes one...... generates entanglement between these two different degrees of freedom. Experimentally we demonstrate amplitude squeezing of an azimuthally polarized mode by exploiting the nonlinear Kerr effect in a specially tailored photonic crystal fiber. These results display that such novel continuous...
Thermal Spin Squeezing as a Signature of Thermal Global Entanglement in Heisenberg Models
Institute of Scientific and Technical Information of China (English)
Mojtaba Jafarpour; Azita Naji
2012-01-01
We study thermal spin squeezing （TSS） and thermal global entanglement （TGE） in a general Heisenberg spin chain, in the presence of Dzyaloshinskii-Moriya interaction and an external magnetic field. We derive an inequality associating the squeezing parameter and the global concurrence, which establishes （TSS） as a signature of （TGE）. The inequality reduces to equality for particular symmetric chains which also associates TSS with bipartite entanglement in such systems. We also check the results by presenting two numerical examples.
Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations.
Ockeloen-Korppi, C F; Damskägg, E; Pirkkalainen, J-M; Heikkilä, T T; Massel, F; Sillanpää, M A
2017-03-10
A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.
Porous Squeeze Film Bearing with Rough Surfaces Lubricated by a Bingham Fluid
Directory of Open Access Journals (Sweden)
Walicka A.
2014-11-01
Full Text Available In the paper the effect of both bearing surfaces and the porosity of one bearing surface on the pressure distribution and load-carrying capacity of a squeeze film bearing is discussed. The equations of motion of a Bingham fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and Christensen theory of rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for a squeeze film bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
Limiting effects of geometrical and optical nonlinearities on the squeezing in optomechanics
Energy Technology Data Exchange (ETDEWEB)
Djorwé, P. [Laboratory of Modelling and Simulation in Engineering, Biomimetics and Prototypes, Faculty of Science, University of Yaoundé I (Cameroon); Nana Engo, S.G., E-mail: nanaengo@gmail.com [Laboratory of Photonics, Faculty of Science, University of Ngaoundéré (Cameroon); Talla Mbé, J.H.; Woafo, P. [Laboratory of Modelling and Simulation in Engineering, Biomimetics and Prototypes, Faculty of Science, University of Yaoundé I (Cameroon)
2013-08-01
In recent experiments, the re-thermalization time of the mechanical resonator is stated as the limiting factor for quantum applications of optomechanical systems. To explain the origin of this limitation, an analytical nonlinear investigation supported by the recent successful experimental laser cooling parameters is carried out in this work. To this end, the effects of geometrical and the optical nonlinearities on the squeezing are studied and are in a good agreement with the experimental results. It appears that highly squeezed state are generated where these nonlinearities are minimized and that high nonlinearities are limiting factors to reach the quantum ground state.
Waveguide splitting and squeezing in zero-index metamaterials embedded with defects
Energy Technology Data Exchange (ETDEWEB)
Ding, Erliang; Wang, Yangyang; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)
2015-10-15
This paper theoretically investigates the reflective properties of splitting and squeezing devices based on a zero-index metamaterial (ZIM) waveguide embedded with defects. This structure can guarantee no reflections, making it possible to build reflectionless splitters and squeezers. Moreover, the proposed theory has been used to couple input and output waveguides with different cross sections and to achieve an arbitrary angle of exotic transmission. The proposed defect structure can offer potential advances in cloaking, splitting, and squeezing technologies without restricting the object’s shape. Active control of exotic transmission can occur by incorporating tunable parameters into the defects and the ZIM.
Bistability and squeezing of the librational mode of an optically trapped nanoparticle
Xiao, Ke-Wen; Zhao, Nan; Yin, Zhang-qi
2017-07-01
We systematically investigate the bistable behavior and squeezing property of the librational mode of a levitated nonspherical nanoparticle trapped by laser beams. By expanding the librational potential to the fourth order of the librational angle θ , we find that the nonlinear coefficient of this mode is dependent only on the size and material of nanoparticle, but independent of trapping potential shape. The bistability and hysteresis are displayed when the driving frequency is red detuned to the librational mode. In the blue-detuned region, we have studied squeezing of the variance of librational mode in detail, which has potential application for measurement of angle and angular momentum.
Comparison of qubit and qutrit like entangled squeezed and coherent states of light
Najarbashi, G.; Mirzaei, S.
2016-10-01
Squeezed state of light is one of the important subjects in quantum optics which is generated by optical nonlinear interactions. In this paper, we especially focus on qubit like entangled squeezed states (ESS's) generated by beam splitters, phase-shifter and cross Kerr nonlinearity. Moreover the Wigner function of two-mode qubit and qutrit like ESS are investigated. We will show that the distances of peaks of Wigner functions for two-mode ESS are entanglement sensitive and can be a witness for entanglement. Like the qubit cases, monogamy inequality is fulfilled for qutrit like ESS. These trends are compared with those obtained for qubit and qutrit like entangled coherent states (ECS).
A new type of photon-added squeezed coherent state and its statistical properties
Institute of Scientific and Technical Information of China (English)
Zhou Jun; Fan Hong-Yi; Song Jun
2012-01-01
We construct a new type of photon-added squeezed coherent state generated by repeatedly operating the bosonic creation operator on a new type of squeezed coherent state [Fan H Y and Xiao M 1996 Phys.Lett.A 220 81].We find that its normalization factor is related to single-variable Hermite polynomials.Furthermore,we investigate its statistical properties,such as Mandel's Q parameter,photon-number distribution,and Wigner function.The nonclassicality is displayed in terms of the intense oscillation of photon-number distribution and the negativity of the Wigner function.
Kraft, Manuel; Hein, Sven M.; Lehnert, Judith; Schöll, Eckehard; Hughes, Stephen; Knorr, Andreas
2016-08-01
Quantum coherent feedback control is a measurement-free control method fully preserving quantum coherence. In this paper we show how time-delayed quantum coherent feedback can be used to control the degree of squeezing in the output field of a cavity containing a degenerate parametric oscillator. We focus on the specific situation of Pyragas-type feedback control where time-delayed signals are fed back directly into the quantum system. Our results show how time-delayed feedback can enhance or decrease the degree of squeezing as a function of time delay and feedback strength.
QUANTUM FLUCTUATIONS IN A MESOSCOPIC DAMPED LC PARALLEL CIRCUIT IN DISPLACED SQUEEZED FOCK STATE
Institute of Scientific and Technical Information of China (English)
GU YONG-JIAN
2001-01-01
We study the quantum effects of a damped LC parallel circuit considering its different performance from an RLC series circuit in classical physics. The damped LC parallel circuit with a source is quantized and the quantum fluctuations of magnetic flux and electric charge in the circuit in displaced squeezed Fock state are investigated. It is shown that, as in the RLC series circuit, the fluctuations only depend on the squeezing parameter and the parameters of the circuit components in the damped LC parallel circuit, but the effects of the circuit components on the fluctuations are different in the two circuits.
Atom-Generated Spatial Multi-Mode Structure of Squeezed Light
Zhang, Mi; Xiao, Zhihao; Dowling, Jonathan P; Novikova, Irina; Mikhailov, Eugeniy E
2015-01-01
We generate a squeezed vacuum field via an interaction between a laser beam and an atomic ensemble. A measurement of the quantum noise of a spatially modified squeezed field is conducted. We find the noise suppression to be greatly affected by the transverse profile of the spatial mask and its position along the propagation direction. We have developed a multimode model to describe the mode structure of the light fields which qualitatively explains the quadrature noise behavior in terms of higher-order Laguerre-Gauss modes.
Porous Squeeze Film Bearing with Rough Surfaces Lubricated by a Bingham Fluid
Walicka, A.; Walicki, E.; Jurczak, P.; Falicki, J.
2014-11-01
In the paper the effect of both bearing surfaces and the porosity of one bearing surface on the pressure distribution and load-carrying capacity of a squeeze film bearing is discussed. The equations of motion of a Bingham fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and Christensen theory of rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for a squeeze film bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
Coherence of a squeezed sodium atom laser generated from Raman output coupling
Institute of Scientific and Technical Information of China (English)
Huiyong He; Chunjia Huang
2009-01-01
The coherence of a squeezed sodium atom laser generated from a Raman output coupler,in which the sodium atoms in Bose-Einstein condensate (BEC) intcract with two light beams consisting of a weaker squeezed coherent probe light and a stronger classical coupling light,is investigated.The results show that in the case of a large mean number of BEC atoms and a weaker probe light field,the atom laser is antibunching,and this atom laser is second-order coherent if the number of BEC atoms in traps is large enough.
1988-12-01
soiidfication front as a funct:on of t:me. Suoerim csea cni t2s ine are ooin:s tlat reoresent t",e exact solution at the corresoonaing t:mes as cotainea from the...Bomoay, (1981). Nomoto, M., "Mechanical Properties of Squeeze Castings in Al- Cu Alloys," Journal Japan Institute Light Metals, Vol. 30 (1980), pp 212-216...5. KaneKo, Y., Murakami, H., Kuroda, K. and Nagazaki, S., "Squeeze Casting of Aluminum," Foundry Trade Journal , Vol. 148 (1980), pp 397-411. 6
Backscatter tolerant squeezed light source for advanced gravitational-wave detectors.
Chua, Sheon S Y; Stefszky, Michael S; Mow-Lowry, Conor M; Buchler, Ben C; Dwyer, Sheila; Shaddock, Daniel A; Lam, Ping Koy; McClelland, David E
2011-12-01
We report on the performance of a dual-wavelength resonant, traveling-wave optical parametric oscillator to generate squeezed light for application in advanced gravitational-wave interferometers. Shot noise suppression of 8.6±0.8 dB was measured across the detection band of interest to Advanced LIGO, and controlled squeezing measured over 5900 s. Our results also demonstrate that the traveling-wave design has excellent intracavity backscattered light suppression of 47 dB and incident backscattered light suppression of 41 dB, which is a crucial design issue for application in advanced interferometers.
Green bright squeezed light from a cw periodically poled KTP second harmonic generator
DEFF Research Database (Denmark)
Andersen, Ulrik Lund; Buchhave, Preben
2002-01-01
We present the experimental observation of bright amplitude squeezed light from a singly resonant second harmonic generator (SHG) based on a periodically poled potassium titanyl phosphate (KTP) crystal. Contrary to conventional SHG, the interacting waves in this device couple efficiently using...
Son, Kwon Joong
2017-08-01
A squeeze film induced by ultrasonic vibration between two solid surfaces in contact can dramatically reduce the friction between them. This phenomenon, so-called the squeeze film effect, has been utilized in variable friction tactile displays for texture rendering purposes. Such tactile displays can provoke a haptic sensation to a finger pad in a controllable way. A real-time adjustment of the coefficient of lateral friction between the human finger pad and the tactile display can be accomplished by modulating the vibration amplitude of the tactile panel. Therefore, driving a reliable friction model is a key step towards designing and controlling tactile displays utilizing the squeeze film effect. This paper derives a modified Herschel- Bulkley rheological model to express the lateral friction exerted on a human fingertip via an air squeeze film as a function of the operating parameters such as the driving voltage amplitude, the finger sliding speed, and the contact pressure. In contrast to the conventional Coulomb friction model, such a rheology model can account for the sliding velocity dependence. This modeling work may contribute to the optimal control of the ultrasonic variable friction tactile displays.
Coupling of effective one-dimensional two-level atoms to squeezed light
Clark, S; Clark, Stephen; Parkins, Scott
2002-01-01
A cavity QED system is analyzed which duplicates the dynamics of a two-level atom in free space interacting exclusively with broadband squeezed light. We consider atoms in a three or four-level Lambda-configuration coupled to a high-finesse optical cavity which is driven by a squeezed light field. Raman transitions are induced between a pair of stable atomic ground states via the squeezed cavity mode and coherent driving fields. An analysis of the reduced master equation for the atomic ground states shows that a three-level atomic system has insufficient parameter flexibility to act as an effective two-level atom interacting exclusively with a squeezed reservoir. However, the inclusion of a fourth atomic level, coupled dispersively to one of the two ground states by an auxiliary laser field, introduces an extra degree of freedom and enables the desired interaction to be realised. As a means of detecting the reduced quadrature decay rate of the effective two-level system, we examine the transmission spectrum o...
A squeeze-like operator approach to position-dependent mass in quantum mechanics
Energy Technology Data Exchange (ETDEWEB)
Moya-Cessa, Héctor M.; Soto-Eguibar, Francisco [Instituto Nacional de Astrofísica, Óptica y Electrónica, Calle Luis Enrique Erro No. 1, Santa María Tonantzintla, San Andrés Cholula, Puebla CP 72840 (Mexico); Christodoulides, Demetrios N. [CREOL/College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700 (United States)
2014-08-15
We provide a squeeze-like transformation that allows one to remove a position dependent mass from the Hamiltonian. Methods to solve the Schrödinger equation may then be applied to find the respective eigenvalues and eigenfunctions. As an example, we consider a position-dependent-mass that leads to the integrable Morse potential and therefore to well-known solutions.
Spin squeezing and Schrödinger cat generation in atomic samples with Rydberg blockade
DEFF Research Database (Denmark)
Opatrný, Tomáš; Mølmer, Klaus
2012-01-01
A scheme is proposed to prepare squeezed states and Schrödinger-cat-like states of the collective spin degrees of freedom associated with a pair of ground states in an atomic ensemble. The scheme uses an effective Jaynes-Cummings interaction which can be provided by excitation of the atoms...
18 CFR 2.17 - Price discrimination and anticompetitive effect (price squeeze issue).
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Price discrimination... discrimination and anticompetitive effect (price squeeze issue). To implement compliance with the Supreme Court... interested person may file petitions to intervene alleging price discrimination and anticompetitive...
To develop a quantitative method for predicting shrinkage porosity in squeeze casting
Institute of Scientific and Technical Information of China (English)
Shaomin Li; Kenichiro Mine; Shinji Sanakanishi; Koichi Anzai
2009-01-01
In order to secure high strength and high elongation of suspension parts, it is critical to predict shrinkage porosity quantitatively. A new simulation method for quantitative predic'don of shrinkage porosity when replenishing molten metal has been proposed for squeeze casting process. To examine the accuracy of the calculation model, the proposed method was applied to a plate model.
Squeezed film damping measurements on a parallel-plate MEMS in the free molecule regime
Mol, L.; Rocha, L.A.; Cretu, E.; Wolffenbuttel, R.F.
2009-01-01
This paper provides experimental validation of the predictions by two recent models for squeezed film damping in the free molecule regime. Measurements were carried out using a parallel-plate microstructure with a 2.29 μm gap operated at pressures from 105 to 101 Pa (corresponding to Knudsen numbers
Using squeeze-film effect to reduce surface friction in electrostatic actuators
DEFF Research Database (Denmark)
Zsurzsan, Tiberiu-Gabriel; Yamamoto, Akio; Zhang, Zhe;
2015-01-01
This paper presents a method of reducing load friction in two degrees-of-freedom (2-DOF) transparent electrostatic induction actuator by using vibration-induced squeeze film effect. An experimental set-up was built to prove the concept. An overall 70% reduction in required driving voltage...
Squeezing effect of the cavity field in the two-atom Jay nes-Cummings model
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Authors investigate the model that two two-level atoms in terac t with a single-mode cavity. The formulation of the time evolution operator for the two-atom Jaynes-Cummings model is presented by the bare-states approach. Besides, squeezing effect of the cavity field is studied and some novel feature s are obtained.
Combined Ramp and Squeeze to 6.5 TeV in the LHC
Solfaroli Camillocci, Matteo; Tomás, Rogelio; Wenninger, Jorg
2016-01-01
The cycle of the LHC is composed of an energy ramp followed by a betatron squeeze, needed to reduce the beta- star value in the interaction points. Since Run 1, studies have been carried out to investigate the feasibility of combining the two operations, thus considerably reducing the duration of the operational cycle. In Run 2, the LHC is operating at the energy of 6.5 TeV that requires a much longer cycle than that of Run 1. Therefore, the performance gains from a Combined Ramp and Squeeze (CRS) is more interesting. Merging the energy ramp and the betatron squeeze could result in a gain of several minutes for each LHC cycle. With increasing maturity of LHC operation, it is now possible to envisage more complex beam manipulations; this paper describes the first machine experiment with beam, aiming at validating the combination of ramp and squeeze, which was performed in 2015, during a machine development phase. The operation experience with the LHC run at 2.51 TeV, when CRS down to 4 meters was deployed and ...
Study on the squeezing effect of open-ended pipe piles
Institute of Scientific and Technical Information of China (English)
Yan-er Lu; Jun-jie Zheng; Jian-hua Yin
2009-01-01
During the installation of a pipe pile, the soil around the pile will be squeezed out. This paper deals with this squeezing effect of open-ended pipe piles using the cylindrical cavity expansion theory. The characteristics of soil with different tension and compression modnli and dilation are involved by applying the elastic theory with different moduli and logarithmic strain. The closed-form solutions of the radius of the plastic region, the displacement of the boundary between the plastic region and the elastic region and the expansion pressure on the external surface of the pipe piles are obtained. When obtaining these solutions, the soil ping in the open-ended pipe pile is considered by employing an incremental filling ratio to quantify the degree of soil plugging. Moreover, the effects of the ratio of tension and compression moduli, angle of dilation and incremental filling ratio on the radius of the plastic region and the expansion pressure on the external surface of the pipe pile are investigated. The parametric analyses show that it is necessary and important to consider the difference between the tension modulus and compression modulus, dilation angle and incremental filling ratio for studying the squeezing effect of open-ended pipe pile installation. It is concluded that the analytical solutions presented in this paper are suitable for studying the squeezing effect of open-ended pipe piles.
A note on “Generalized superposition of two squeezed states: generation and statistical properties”
Avelar, A. T.; Malbouisson, J.M.C.; Baseia, B.
2004-01-01
Texto completo: acesso restrito. p. 139-143 A previous scheme [Physica A 280 (2003) 346] showed how to create a generalized superposition of two squeezed states for stationary fields and studied its statistical properties. Here we show how to extend this result for travelling fields.
Autonomous Control System for a Squeeze Mode Mr Vibration Isolator in an Automotive Engine Mount
Directory of Open Access Journals (Sweden)
Rosół Maciej
2014-09-01
Full Text Available The investigated autonomous control system for a squeeze mode magnetorheological (MR vibration isolator is based on an ultra-low power microcontroller MSP430F5529. The design structure of the control system and the dedicated real-time system are briefly presented and the laboratory testing data are summarised.
A magneto-rheological fluid mount featuring squeeze mode: analysis and testing
Chen, Peng; Bai, Xian-Xu; Qian, Li-Jun; Choi, Seung-Bok
2016-05-01
This paper presents a mathematical model for a new semi-active vehicle engine mount utilizing magneto-rheological (MR) fluids in squeeze mode (MR mount in short) and validates the model by comparing analysis results with experimental tests. The proposed MR mount is mainly comprised of a frame for installation, a main rubber, a squeeze plate and a bobbin for coil winding. When the magnetic fields on, MR effect occurs in the upper gap between the squeeze plate and the bobbin, and the dynamic stiffness can be controlled by tuning the applied currents. Employing Bingham model and flow properties between parallel plates of MR fluids, a mathematical model for the squeeze type of MR mount is formulated with consideration of the fluid inertia, MR effect and hysteresis property. The field-dependent dynamic stiffness of the MR mount is then analyzed using the established mathematical model. Subsequently, in order to validate the mathematical model, an appropriate size of MR mount is fabricated and tested. The field-dependent force and dynamic stiffness of the proposed MR mount are evaluated and compared between the model and experimental tests in both time and frequency domains to verify the model efficiency. In addition, it is shown that both the damping property and the stiffness property of the proposed MR mount can be simultaneously controlled.
Density Matrix and Squeezed Vacuum State for General Coupling Harmonic Oscillator
Institute of Scientific and Technical Information of China (English)
SONG Tong-Qiang
2003-01-01
By taking a unitary transformation approach, we study two harmonic oscillators with both kinetic coupling and coordinate coupling terms, and derive the density matrix of the system. The results show that the ground state of the system is a rotated two single-mode squeezed state.
Atomic Dipole Squeezing in the Correlated Two-Mode Two-Photon Jaynes-Cummings Model
Dong, Zhengchao; Zhao, Yonglin
1996-01-01
In this paper, we study the atomic dipole squeezing in the correlated two-mode two-photon JC model with the field initially in the correlated two-mode SU(1,1) coherent state. The effects of detuning, field intensity and number difference between the two field modes are investigated through numerical calculation.