Institute Of Theoretical Physics Research Articles

Vibratile Coherence and Squeezing in Two Trapped Ions**The project supported by National Natural Science Foundation of China (19734006,10075018), EYTF of the Educational Department of China, the Chinese Academy of Sciences, Huanan Provincial STF, and s special project of NSF of China via Institute of TheoreticalPhysics, Academia Sinica

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.

Peter Mazur

Peter Mazur, one of the founders of nonequilibrium thermodynamics, died on 15 August 2001 following a short illness. Born on 11 December 1922 in Vienna, Austria, he died in Switzerland, where he had lived after his retirement. During World War II, Mazur had to go into hiding for about three years in various farms in the Dutch countryside. He then began studying chemistry at Utrecht University in the Netherlands.In 1951, Mazur obtained his doctorate under the direction of Sybren de Groot with a thesis entitled, “Thermodynamics of Transport Phenomena in Liquid Helium-2.” The results were in good agreement with experiments done at the Kamerlingh Onnes Laboratory in Leiden, the Netherlands.After many futile attempts to obtain a theoretical foundation for experimentally established reciprocal relations, Lars Onsager finally (in 1931) showed that such relations were a general consequence of the invariance of the microscopic equations of motion under time reversal. Josef Meixner in 1941 and, independently, Ilya Prigogine in 1947 set up a consistent phenomenological theory of irreversible processes, incorporating both Onsager’s reciprocity theorem and the explicit calculation for some systems of the so-called entropy source strength. Shortly thereafter, Mazur and de Groot joined this group as founding fathers of the new field of nonequilibrium thermodynamics. After a period as a postdoctoral fellow at the University of Maryland, College Park, Mazur became an associate professor at Leiden University in 1954. He and de Groot, who had also moved to Leiden, founded, in 1955, the Lorentz Institute for Theoretical Physics at Leiden University. In 1961, Mazur became a full professor, and when de Groot left in 1963, he became director of the institute. He filled this position in his own distinctive way for 25 years until he became emeritus in 1988. Under the direction of de Groot and Mazur, the institute grew substantially and eventually established the Lorentz Chair, a prestigious special professorship.In his first years at Leiden University, Mazur studied the classical and quantum molecular foundations of nonequilibrium thermodynamics. Significant results included the derivation of the Langevin equation with one of us (Oppenheim) and the classic paper on harmonic oscillator systems by George Ford, Mark Kac, and Mazur, which was published in the Journal of Mathematical Physics (in 1965). Mazur’s work in the 1950s and 1960s culminated in the publication of Nonequilibrium Thermodynamics (North-Holland and Interscience, 1962), written by de Groot and Mazur. This book, translated into several languages, became a classic in the field and was later republished as a series of classic monographs.Mazur’s work in subsequent years addressed a variety of problems in statistical mechanics. He had a good nose for problems ripe to be investigated. To describe diffusion of large particles in fluids, he introduced, together with one of us (Bedeaux), the concept of induced forces in 1974. This concept was used to derive generalizations of Faxen’s theorem and to develop a theory for the viscosity of a suspension. In 1976, Mazur, with Bedeaux and Alfonso Albano, gave the first systematic formulation of non-equilibrium thermodynamics for surfaces. This formulation opened a new field, which is still in active development. And Mazur, Wim van Saarloos, and Carlo Beenakker developed an algebraic method around 1982 to successfully describe hydrodynamic interactions between arbitrary numbers of particles using induced forces. This was a breakthrough in the field.After retiring in 1988, Mazur remained active. In 1991, he derived, with Bedeaux, the Langevin equation for a Brownian particle using only causality and time-reversal invariance. From 1994 to 2000, Mazur, together with J. Miguel Rubi, used the method of internal degrees of freedom to describe fluctuations in the context of nonequilibrium thermodynamics. In 2001, he and Bedeaux developed nonequilibrium thermodynamics for quantum systems.Many of Mazur’s colleagues and students have good memories of his flamboyant lecture style and the often heated discussions in front of the blackboard. He insisted on a crystal-clear introduction followed by a detailed derivation of the results. And he thoroughly disliked sentences such as, “It can be easily shown that….” It was great to work with him.Mazur served on the boards of the International Union of Pure and Applied Physics (1966–84) and the Dutch Foundation for Fundamental Research of Matter (1970–85). In 1987, Queen Beatrix made Mazur a Knight of the Order of the Netherlands Lion.Mazur was an excellent scientist, and superb teacher and colleague, whose knowledge and interests encompassed not only science, but almost all fields of intellectual endeavor. A great man, he was devoted to his family, friends, and colleagues. We will miss him dearly.Peter MazurC. W. J. BEENAKKERPPT|High resolution© 2002 American Institute of Physics.

The Relativistic Covariance of the Fermion Green Function and Minimal Quantization of Electrodynamics**The project supported in part by Institute of Theoretical Physics, the Chinese Academy of Sciences, the Third World Academy of Sciences and Vietnam National Research Programme in National Sciences

This paper is devoted to the one-loop calculation of the fermion Green function in QED within the framework of the minimal quantization method, based on an explicit solution of the constraint equations and the gauge-invariance principle. The relativistic invariant expression for the fermion Green function with correct analytical properties is obtained.

G.K. BATCHELOR AND THEHOMOGENIZATION OFTURBULENCE

▪ Abstract This essay is based on the G.K. Batchelor Memorial Lecture that I delivered in May 2000 at the Institute for Theoretical Physics (ITP), Santa Barbara, where two parallel programs on Turbulence and Astrophysical Turbulence were in progress. It focuses on George Batchelor's major contributions to the theory of turbulence, particularly during the postwar years when the emphasis was on the statistical theory of homogeneous turbulence. In all, his contributions span the period 1946–1992 and are for the most part concerned with the Kolmogorov theory of the small scales of motion, the decay of homogeneous turbulence, turbulent diffusion of a passive scalar field, magnetohydrodynamic turbulence, rapid distortion theory, two-dimensional turbulence, and buoyancy-driven turbulence.

Transport phenomena

Transport phenomena

Quinn Is Elected Vice President of APS

The American Physical Society has elected Helen Quinn, a research physicist at SLAC, vice president for 2002. Taking office 1 January, she succeeds Myriam Sarachik and will become president-elect in 2003 and president in 2004. This marks the first time APS has had consecutive women vice presidents.“We must work together with other science-based professional societies to ensure that the need for both basic and applied research and the interconnections between basic work in one area and later applied work are understood,” says Quinn. She adds that the society must also ensure that physicists are aware when science-related issues are before Congress, and facilitate activities to help physicists’ voices contribute effectively to the political dialogue.Quinn received three degrees in physics: a BS in 1963, an MS in 1964, and her PhD in 1967, all from Stanford University. She held postdoctoral positions at the German Electron Synchrotron and at Harvard University, and became an assistant professor of physics at Harvard in 1972. In 1979, she moved to SLAC, where she currently focuses on the phenomenology of B mesons, in particular whether their decays, including charge conjugation-parity violation decays, conform to the Standard Model. Quinn is active in physics education outreach, and is especially involved in the training of physics teachers. In other APS election results, also taking office on 1 January will be the new chairelect of the APS nominating committee, Susan Seestrom, director of the physics division at Los Alamos National Laboratory. The new APS international councillor will be T. Maurice Rice, a professor with the Institute for Theoretical Physics at the Swiss Federal Institute of Technology (ETH). The two new members of the APS general council are Frances Houle, a researcher in the science and technology department at the IBM Almaden Research Center in San Jose, California, and Gerald Mahan, distinguished professor of physics at Pennsylvania State University. Quinn PPT|High resolution© 2001 American Institute of Physics.

Raman Theory for a Molecule in a Vibrating Microcavity Oscillating in Fundamental Resonance**The project supported in part by National Natural Science Foundation of China under Grant Nos 69788002 and 60078023, and Institute of Theoretical Physics, The Chinese Academy of Sciences

We propose a model to describe the energy structure and dynamics of a system of a molecule interacting with infinite photon modes in a vibrating microcavity whose boundary oscillates in the fundamental resonance. By constructing an Lie algebra for the infinite photon modes, we obtain analytical expressions of the energy eigenstates, energy eigenvalues and the system's evolution operator for this Raman model under certain conditions.

APS Honors Physics Contributions

APS Honors Physics Contributions

NEWS

NEWS

Semiclassical versus quantal time-dependent mean-field descriptions of electron dynamics in ion-cluster collisions

Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan~Received 22 July 1999; published 15 February 2000!Both quantal and semiclassical mean-field theories based on the density-functional theory have recently beenapplied to describe the dynamical evolution of electrons during and after the collision between highly chargedions and metallic clusters. We here compare and assess both methods. The quantal calculation solves thetime-dependent Kohn-Sham equations, whereas the semiclassical one solves the Vlasov equation with the sameexchange-correlation functional. Predicted observables such as electron transfer and residual electronic exci-tations are in excellent agreement with each other. Ranges of applicability of both methods are discussed andcomplementarities are emphasized.PACS number~s!: 36.40.2cI. INTRODUCTION

Jamming in Liquids and Granular Materials

Many systems can develop a yield stress while in an amorphous state. For example, a supercooled liquid, when cooled sufficiently, forms a glass - an amorphous solid with a yield stress. Another common example is a granular material which will remain solid and not move even under the influence of moderate stresses. This accounts for why piles of grain or sand can exist with a non-zero slope even though gravity is acting to flatten out the upper surface. The solidity in that case is due to the system having become jammed. Similar jamming often inhibits flow out of a hopper or in conduits transporting material across a factory floor. Jamming is a ubiquitous phenomenon occurring in many different systems such as colloidal suspensions, foams and, of course, traffic. We tend to think of the jamming transition as being stress-induced. A “fluid” at constant density (or under a confining pressure) flows if the stress is above the yield stress but becomes stuck in an amorphous configuration if the stress is too low. The idea of temperature, per se, does not seem to be crucial to the transition. This makes it seems quite different from the formation of a glass out of a supercooled liquid by lowering the temperature. However, there are similarities between these two types of transitions, aside from the obvious fact that they both have to do with the complete arrest of dynamics and flow. An exploration of these similarities was the subject of a program at the Institute for Theoretical Physics in Santa Barbara held in the Autumn of 1997. A synopsis of this program was published that details some of the interesting ideas now current in that field.[1]

Computing in Physics: Are We Taking It Too Seriously? or Not Seriously Enough?

A of us who are involved in the sciences know that the computer has become an essential tool for research. We're impressed and perhaps surprised that Moore's law of exponential growth in computing power has persisted for three decades. I'm certainly surprised to be writing these remarks on a laptop that does most of what supercomputers could do just a few years ago. I enjoy using this device, and Fm eager to look through the new window on the natural world that is being opened by the next generation of supercomputers. But Fm also uneasy. I wrote in a report last year that scientific computation has reached the point where it is on a par with laboratory experiment and mathematical theory as a tool for research in science and engineering. I think that statement is true. If so, however, it implies more of a change in the way we do research than many may realize. Ill explain by recalling some history and discussing a few examples. As readers of PHYSICS TODAY must know, Walter Kohn won the 1998 Nobel Prize in Chemistry for his density functional theory of many-electron systems. Many readers also know that Walter was the founding director (1979-84) of the Institute for Theoretical Physics in Santa Barbara, California. He defined goals for the ITP, established its mode of operation and, most importantly, by the policies that he adopted and his personal example, set standards for all of us who were lucky enough to be engaged in the enterprise. Walter is a person of firm principles. Among those principles, in 1979, was that the ITP should be first and foremost a physics institute, not a computing center. His original National Science Foundation budget for the ITP relied on existing on-campus computers; it was not until some years later that we acquired a small mainframe.

Quantum Statistical Properties of Photons and Atoms in Interaction of an Atomic Bose–Einstein Condensate with Lasers**The project supported in part by National Natural Science Foundation of China, the Natural Science Foundation of Hunan Province and special project of the NSF Through The Institute of Theoretical Physics, Academia Sinica

In this paper, we study quantum statistical properties of atoms and photons in interaction of -atomic Bose–Einstein condensate in the ground-state hyperfine sublevels with laser fields. We investigate not only quantum conversions between atoms in the condensate and photons in the quantized laser field, but also transfer of nonclassical characteristics of atoms and photons between input states and output states when the atom field is initially in a number state and the quantized laser field is in the even coherent state and the odd coherent state, respectively. We find various conditions to realize these quantum conversions. We also study atom-photon quantum correlations and their input-output conversions. It is indicated that there are atom-field nonclassical correlations.

A tale of two continents: a physicist's life in a turbulent world

People like myself, who truly feel at home in several countries, are not strictly at home anywhere, writes Abraham Pais, one of the world's leading theoretical physicists and author of the biography of Einstein, Subtle is the Lord, near the beginning of this chronicle of his life on two continents. His tale describes his period of hiding in Nazi-occupied Holland (he ended the war in a Gestapo prison) and his life in America, particularly at the newly organized Institute for Advanced Study in Princeton, then directed by the brilliant and controversial physicist Robert Oppenheimer. Pais tells fascinating stories about Oppenheimer, Einstein, Bohr, Sakharov, Dirac, Heisenberg, and von Neumann, as well as about nonscientists like Chaim Weizmann, George Kennan, Erwin Panofsky, and Pablo Casals. His enthusiasm about science and life in general pervades a book that is partly a memoir, partly a travel commentary, and partly a history of science. His recollections of his years as a university student become sombre with the German invasion of the Netherlands in 1940. He was presented with an unusual deadline for his graduate work: a German decree that July 14, 1941, would be the final date on which Dutch Jews could be granted a doctoral degree. Pais received the degree, only to be forced into hiding from the Nazis in 1943, practically next door to Anne Frank. After the war, he went to the Institute of Theoretical Physics in Copenhagen to work with Niels Bohr. In 1946 he began his years at the Institute for Advanced Study, where he worked first as a Fellow and then as a Professor until his move to Rockefeller University in 1963. Combining his understanding of disparate social and political worlds, Pais comments on Oppenheimer's ordeals during the McCarthy era and his own and his European colleagues' struggles during World War II.

George A. Kolstad (1919–1996)

George A. Kolstad, creator and leader of the U.S. Department of Energy's Geosciences Research Program, died of an aneurysm August 7, 1996, in Baltimore, Md. He is survived by Chris, his wife of 52 years, three children, Martha Rae Kolstad Wilhelm of Grinnell, Iowa, Charles D. Kolstad of Santa Barbara, Calif., and Peter K. Kolstad, of Los Angeles, Calif., and four grandchildren. George is also survived by three brothers and a sister.George was born in Elmira, N.Y., on December 10, 1919. Following high school graduation in 1937, he worked at Eastman Kodak while enrolled in night courses at the Rochester Institute of Technology and the University of Rochester. He entered Bates College in 1939 and completed his B.S. in physics and mathematics in 1943. During World War II, he worked on piezo‐electricity, radar countermeasures, and information flow from radar systems in combat environments. Following his Ph.D. in physics at Yale and brief service on the faculty there, he joined the Atomic Energy Commission in 1950. He began a career of fostering and nurturing basic research efforts, first in physics and mathematics, and then in the geosciences. He was a guest staff member at the Institute for Theoretical Physics, Copenhagen, in 1956–1957, and served as a trustee of Bates College from 1958 to 1964.

Fixed-Term Employment System -- The Case of Yukawa Institute for Theoretical Physics

Fixed-Term Employment System -- The Case of Yukawa Institute for Theoretical Physics

MIXING FOR AREA-PRESERVING FLOWS ON THE TWO-DIMENSIONAL TORUS

International Journal of Modern Physics BVol. 10, No. 18n19, pp. 2167-2188 (1996) No AccessMIXING FOR AREA-PRESERVING FLOWS ON THE TWO-DIMENSIONAL TORUSK.M. KHANINK.M. KHANINLandau Institute for Theoretical Physics, Russian Academy of Sciences, Kosygina 2, Moscow 117940, Russiahttps://doi.org/10.1142/S0217979296000994Cited by:1 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail This paper is based on a joint work with Ya. G. Sinai published in Funkts. Anal. i ego Prilozkeniya, v.26:3, pp. 1–21. Our interest in the problem was motivated by an earlier paper of V.I. Arnold.1 You currently do not have access to the full text article. Recommend the journal to your library today! FiguresReferencesRelatedDetailsCited By 1Special Flow, Weak Mixing and ComplexityWen Huang and Leiye Xu10 December 2018 | Communications in Mathematics and Statistics, Vol. 7, No. 1 Recommended Vol. 10, No. 18n19 Metrics History PDF download

The Burridge-Knopoff model

J. M. Carlson, J. S. Langer, and B. E. Shaw at the Institute for Theoretical Physics in Santa Barbara, California, have discussed the Burridge-Knopoff model for earthquake faults, and this paper considers an analytic solution that does not require linearization or perturbation.

Introduction

The Workshop on Atom Optics was held at the University of Adelaide in September 1995. It was attended by pproximately 40 physicists from Australia and New Zealand. The venue for the workshop was the new Institute for Theoretical Physics at the University of Adelaide which provided excellent facilities for lectures and discussion. Atom optics is a field which has grown rapidly since its beginning approximately five years ago. There are now several groups in Australia and New Zealand pursuing research activities in both theoretical and experimental aspects of atom optics.

Duality of Orbifoldized Elliptic Genera

We discuss duality and mirror symmetry phenomena of Landau-Ginzburg orbifolds considering their elliptic genera. Under the duality (or mirror) transform performed by orbifoldizing the Landau-Ginzburg model via some discrete group of the superpotential we observe that the roles of the untwisted and twisted sectors are exchanged. As explicit evidence detailed orbifold data are presented for $N=2$ minimal models, Arnold's exceptional singularities, $K3$ surfaces constructed from Arnold's singularities and Fermat hypersurfaces. (To appear in the proceedings of the workshop, ``Quantum Field Theory, Integrable Models and Beyond'', Yukawa Institute for Theoretical Physics, Kyoto University, 14-18 February 1994.)