Collective Excitations in Unconventional Superconductors and Superfluids


Book Description

This is the first monograph that strives to give a complete and detailed description of the collective modes (CMs) in unconventional superfluids and superconductors (UCSF&SC). Using the most powerful method of modern theoretical physics OCo the path (functional) integral technique OCo authors build the three- and two-dimensional models for s -, p - and d -wave pairing in neutral as well as in charged FermiOCosystems, models of superfluid BoseOCosystems and FermiOCoBoseOComixtures. Within these models they study the collective properties of such systems as superfluid 3 He, superfluid 4 He, superfluid 3 He- 4 He mixtures, superfluid 3 He-films, superfluid 3 He and superfluid 3 He- 4 He mixtures in aerogel, high temperature superconductors, heavy-fermion superconductors, superconducting films etc. Authors compare their results with experimental data and predict a lot of new experiments on CMs study. This opens for experimentalists new possibilities for search of new intriguing features of collective behavior of UCSF&SC. The monograph creates the new scientific direction OCo the spectroscopy of collective modes in unconventional superfluids and superconductors. It will be useful for both theorists and experimentalists, studying superfluids and superconductors, low temperature physics, condensed matter physics, solid state physics. It could be used by graduate students specializing in the same areas. Sample Chapter(s). Introduction (162 KB). Chapter 1: Functional Integration Method (369 KB). Contents: Functional Integration Method; Collective Excitations in Superfluid Fermi-Systems with s OCoPairing; Superfluid Phases in 3 He; The Model of 3 He; Collective Excitations in the B OCoPhase of 3 He; Collective Excitations in the A OCoPhase of 3 He; Stability of Goldstone Modes; Influence of Dipole Interaction and Magnetic Field on Collective Excitations; The Influence of the Electric Field on the Collective Excitations in 3 He and 4 He; The Order Parameter Distortion and Collective Modes in 3 HeOCo B; Collective Excitations in the Planar 2 D OCoPhase of Superfluid 3 He; Collective Excitations in the PolarOCoPhase; Superfluidity of TwoOCoDimensional and One-Dimensional Systems; BoseOCoSpectrum of Superfluid Solutions 3 He- 4 He; Novel Sound Phenomena in Impure Superfluids; Collective Modes in the HeavyOCoFermion Superconductors; Other Application of the Theory of Collective Excitations. Readership: Graduate and postgraduate students, researchers (theorists and experimentalists), in low temperature physics, superconductivity and condensed matter physics."




Nonlinear Dynamics and Shock Structures in Elongated Bose-Einstein Condensates


Book Description

Dilute gas Bose-Einstein condensates are ultracold quantum gases that display many peculiar hydrodynamic properties, such as superfluidity, i.e. dissipation-less flow, a variety of solitonic textures and quantized vortex structures. Small amplitude excitations within a Bose-Einstein condensate are described by the Bogoliubov dispersion, and have been extensively studied in the past. This dissertation extends previous studies by focusing on strong, nonlinear excitations and shock structures generated in elongated Rb-87 Bose-Einstein condensates, elucidating novel dynamics in these quantum systems.This dissertation is separated into two major parts. In the first part, the building and characterization of a new Bose-Einstein condensate apparatus at Washington State University is described. This apparatus has been built to generate ultracold clouds of Rb-87 and, more recently, K-41atoms. A description of the setups for both isotopes are provided. The apparatus reliably produces Bose-Einstein condensates of 7 x 105 Rb-87 atoms every 20 seconds.In the second part of this dissertation, three experiments in a channel geometry are described that have been conducted with the new apparatus. In this part of the dissertation, quantum hydrodynamic properties are probed by using time-dependent optical potentials to generate nonlinear excitations and shock structures in an elongated Bose-Einstein condensate. An emergence of viscous-like shock dynamics, unidirectionality of a non-magnetic spin switch device, and the structure of dispersive shock waves in new types of higher order dispersions are observed. The work described in this dissertation establishes a novel platform for studying strong nonlinear effects in ultracold quantum gases.




Bose-Einstein Condensation and Superfluidity


Book Description

Ultracold atomic gases is a rapidly developing field of physics that attracts many young researchers around the world. This book gives a comprehensive overview of exciting developments in Bose-Einstein condensation and superfluidity from a theoretical perspective and makes sense of key experiments with a special focus on ultracold atomic gases.




Superfluid States of Matter


Book Description

Covers the State of the Art in Superfluidity and SuperconductivitySuperfluid States of Matter addresses the phenomenon of superfluidity/superconductivity through an emergent, topologically protected constant of motion and covers topics developed over the past 20 years. The approach is based on the idea of separating universal classical-field superf




Novel Superfluids


Book Description

This book reports on the latest developments in the field of Superfluidity, one of the most fundamental, interesting, and important problems in physics, with applications ranging from metals, helium liquids, photons in cavities, excitons in semiconductors, to the interior of neutron stars and the present state of the Universe as a whole.




Bose-Einstein Condensation of Excitons and Biexcitons


Book Description

Bose-Einstein condensation of excitons is a unique effect in which the electronic states of a solid can self-organize to acquire quantum phase coherence. The phenomenon is closely linked to Bose-Einstein condensation in other systems such as liquid helium and laser-cooled atomic gases. This is the first book to provide a comprehensive survey of this field, covering theoretical aspects as well as recent experimental work. After setting out the relevant basic physics of excitons, the authors discuss exciton-phonon interactions as well as the behaviour of biexcitons. They cover exciton phase transitions and give particular attention to nonlinear optical effects including the optical Stark effect and chaos in excitonic systems. The thermodynamics of equilibrium, quasi-equilibrium, and nonequilibrium systems are examined in detail. The authors interweave theoretical and experimental results throughout the book, and it will be of great interest to graduate students and researchers in semiconductor and superconductor physics, quantum optics, and atomic physics.




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.




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.