Excitations in a Bose-condensed Liquid


Book Description

This volume gives an up-to-date, systematic account of the microscopic theory of Bose-condensed fluids developed since the late 1950s. In contrast to the usual phenomenological discussions of superfluid 4He, the present treatment is built on the pivotal role of the Bose broken symmetry and a Bose condensate. The many-body formalism is developed, with emphasis on the one- and two-particle Green's functions and their relation to the density response function. These are all coupled together by the Bose broken symmetry, which provides the basis for understanding the elementary excitations and response functions in the hydrodynamic and collisionless regions. It also explains the difference between excitations in the superfluid and normal phases. Chapter 4 gives the first critical assessment of the experimental evidence for a Bose condensate in liquid 4He, based on high-momentum neutron scattering data.




Liquid Glass Transition


Book Description

A glass is disordered material like a viscous liquid and behaves mechanically like a solid. A glass is normally formed by supercooling the viscous liquid fast enough to avoid crystallization, and the liquid-glass transition occurs in diverse manners depending on the materials, their history, and the supercooling processes, among other factors. The glass transition in colloids, molecular systems, and polymers is studied worldwide. This book presents a unified theory of the liquid-glass transition on the basis of the two band model from statistical quantum field theory associated with the temperature Green's function method. It is firmly original in its approach and will be of interest to researchers and students specializing in the glass transition across the physical sciences. - Examines key theoretical problems of the liquid-glass transition and related phenomena - Clarifies the mechanism and the framework of the liquid-glass transition




Elementary Excitations in Quantum Fluids


Book Description

This volume is the proceedings of the Hiroshima Symposium on Elementary Excitations in Quantum Fluids, which was held on August 17 and 18, 1987, in Hiroshima, Japan, and was attended by thirty-two scientists from seven countries. Quantum fluids have been the subject of intense study as a consequence of their superfluid properties at very low temperatures. Elementary excitations in them are an important concept about which many important discoveries have been made in recent years. This symposium was arranged by a group of physicists from Hiroshima University to provide an opportunity to discuss these recent developments. It was conceived as a satellite conference of the 18th International Conference on Low Temperature Physics (LT 18), which was held in Kyoto, August 20-26, 1987. Emphasis was placed on the dynamic structures and correlations of ele mentary excitations, which resulted in invited speakers being selected from this field. However, enthusiastic contributors reported notable new results on various other aspects of the elementary excitations, which made the sympo sium lively and successful. It is our great satisfaction to present this volume, which includes papers of good quality and originality. We thank all the parti cipants for their cooperation throughout this symposium, and for preparing their manuscripts within a reasonable time.




Bose-Einstein Condensation


Book Description

Among the most remarkable effects that quantum mechanics adds to the catalog of the thermal properties of matter is "condensation" of an ideal gas of identical particles into a single quantum state, the principle of which was discovered in the theory of statistical mechanics by Bose and Einstein in the 1920s. Bose-Einstein condensation (BEC) is a mechanism for producing a macroscopic quantum system, and is exemplary of the macroscopic quantum phenomena of superconductivity and superfluidity.These 15 papers provide an introduction to current work on BEC.




Bose-Condensed Gases at Finite Temperatures


Book Description

The discovery of Bose–Einstein condensation (BEC) in trapped ultracold atomic gases in 1995 has led to an explosion of theoretical and experimental research on the properties of Bose-condensed dilute gases. The first treatment of BEC at finite temperatures, this book presents a thorough account of the theory of two-component dynamics and nonequilibrium behaviour in superfluid Bose gases. It uses a simplified microscopic model to give a clear, explicit account of collective modes in both the collisionless and collision-dominated regions. Major topics such as kinetic equations, local equilibrium and two-fluid hydrodynamics are introduced at an elementary level. Explicit predictions are worked out and linked to experiments. Providing a platform for future experimental and theoretical studies on the finite temperature dynamics of trapped Bose gases, this book is ideal for researchers and graduate students in ultracold atom physics, atomic, molecular and optical physics and condensed matter physics.




New Approaches to Problems in Liquid State Theory


Book Description

The theory of simple and complex fluids has made considerable recent progress, due to the emergence of new concepts and theoretical tools, and also to the availability of a large body of new experimental data on increas ingly complex systems, as well as far-reaching methodological developments in numerical simulations. This AS! aimed at providing a comprehensive overview of the most significant theoretical developments, supplemented by a few presentations of cutting-edge simulation and experimental work. The impact of the Institute in the overall landscape of Statistical Mechanics received an important recognition with its inclusion in the list of satellite events of STATPHYS20, the triennal international conference on Statistical Physics held in Paris in July 1998. These Proceedings contain the texts of the 13 Lecture Courses and 9 Invited Seminars delivered at Patti. Two clear trends emerge from these Proceedings: first, the diversity of new and unexpected theoretical results relating to classic models of liq uids, which have recently been subjected to fresh scrutiny; and secondly the parallel emergence of new concepts, models and methods, aimed at investigating complex fluids and phenomena, like the phase behaviour of fluids in pores, macromolecular assemblies, and the glass transition. Many of the new tools have their roots in traditional liquid state theory, and, in conjunction with fresh input from related fields, allow it wider applicability.







Condensazione Di Bose-Einstein Nei Gas Atomici


Book Description

Although first proposed by Einstein in 1924, Bose-Einstein condensation (BEC) in a gas was not achieved until 1995 when, using a combination of laser cooling and trapping, and magnetic trapping and evaporation, it was first observed in rubidium and then in lithium and sodium, cooled down to extremely low temperatures. This book brought together many leaders in both theory and experiment on Bose-Einstein condensation in gases. Their lectures provided a detailed coverage of the experimental techniques for the creation and study of BEC, as well as the theoretical foundation for understanding the properties of this novel system. This volume provides the first systematic review of the field and the many developments that have taken place in the past three years.




Bose-einstein Condensation - From Atomic Physics To Quantum Fluids, Procs Of The 13th Physics Summer Sch


Book Description

Bose-Einstein condensation of dilute gases is an exciting new field of interdisciplinary physics. The eight chapters in this volume introduce its theoretical and experimental foundations. The authors are lucid expositors who have also made outstanding contributions to the field. They include theorists Tony Leggett, Allan Griffin and Keith Burnett, and Nobel-Prize-winning experimentalist Bill Phillips. In addition to the introductory material, there are articles treating topics at the forefront of research, such as experimental quantum phase engineering of condensates, the “superchemistry” of interacting atomic and molecular condensates, and atom laser theory.




Universal Themes of Bose-Einstein Condensation


Book Description

Following an explosion of research on Bose–Einstein condensation (BEC) ignited by demonstration of the effect by 2001 Nobel prize winners Cornell, Wieman and Ketterle, this book surveys the field of BEC studies. Written by experts in the field, it focuses on Bose–Einstein condensation as a universal phenomenon, covering topics such as cold atoms, magnetic and optical condensates in solids, liquid helium and field theory. Summarising general theoretical concepts and the research to date - including novel experimental realisations in previously inaccessible systems and their theoretical interpretation - it is an excellent resource for researchers and students in theoretical and experimental physics who wish to learn of the general themes of BEC in different subfields.