Non Equilibrium Dynamics Of Tunnel Coupled Superfluids

Download or read book Non-equilibrium Dynamics of Tunnel-Coupled Superfluids written by Marine Pigneur and published by Springer Nature. This book was released on 2020-08-28 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relaxation of isolated quantum many-body systems is a major unsolved problem of modern physics, which is connected to many fundamental questions. However, realizations of quantum many-body systems which are both well isolated from their environment and accessible to experimental study are scarce. In recent years, the field has experienced rapid progress, partly attributed to ultra-cold atoms. This book presents the experimental study of a relaxation phenomenon occurring in a one-dimensional bosonic Josephson junction. The system consists of two 1D quasi Bose-Einstein condensates of 87Rb, magnetically trapped on an atom chip. Using radio-frequency dressing, the author deforms a single harmonic trap, in which the atoms are initially condensed, into a double-well potential and realizes a splitting of the wave function. A large spatial separation and a tilt of the double-well enable the preparation of a broad variety of initial states by precisely adjusting the initial population and relative phase of the two wave packets, while preserving the phase coherence. By re-coupling the two wave packets, the author investigates tunneling regimes such as Josephson (plasma) oscillations and macroscopic quantum self-trapping. In both regimes, the tunneling dynamics exhibits a relaxation to a phase-locked equilibrium state contradicting theoretical predictions. The experimental results are supported with an empirical model that allows quantitative discussions according to various experimental parameters. These results illustrate how strongly the non-equilibrium dynamics differ from the equilibrium one, which is well described by thermodynamics and statistical physics.

Download or read book Non-equilibrium Dynamics of One-Dimensional Bose Gases written by Tim Langen and published by Springer. This book was released on 2015-05-22 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a series of experiments with ultracold one-dimensional Bose gases, which establish said gases as an ideal model system for exploring a wide range of non-equilibrium phenomena. With the help of newly developed tools, like full distributions functions and phase correlation functions, the book reveals the emergence of thermal-like transient states, the light-cone-like emergence of thermal correlations and the observation of generalized thermodynamic ensembles. This points to a natural emergence of classical statistical properties from the microscopic unitary quantum evolution, and lays the groundwork for a universal framework of non-equilibrium physics. The thesis investigates a central question that is highly contested in quantum physics: how and to which extent does an isolated quantum many-body system relax? This question arises in many diverse areas of physics, and many of the open problems appear at vastly different energy, time and length scales, ranging from high-energy physics and cosmology to condensed matter and quantum information. A key challenge in attempting to answer this question is the scarcity of quantum many-body systems that are both well isolated from the environment and accessible for experimental study.

Download or read book Universal Themes of Bose-Einstein Condensation written by Nick P. Proukakis and published by Cambridge University Press. This book was released on 2017-04-27 with total page 663 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering general theoretical concepts and the research to date, this book demonstrates that Bose-Einstein condensation is a truly universal phenomenon.

Download or read book Quantum Gases: Finite Temperature And Non-equilibrium Dynamics written by Nick P Proukakis and published by World Scientific. This book was released on 2013-02-21 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1995 observation of Bose-Einstein condensation in dilute atomic vapours spawned the field of ultracold, degenerate quantum gases. Unprecedented developments in experimental design and precision control have led to quantum gases becoming the preferred playground for designer quantum many-body systems.This self-contained volume provides a broad overview of the principal theoretical techniques applied to non-equilibrium and finite temperature quantum gases. Covering Bose-Einstein condensates, degenerate Fermi gases, and the more recently realised exciton-polariton condensates, it fills a gap by linking between different methods with origins in condensed matter physics, quantum field theory, quantum optics, atomic physics, and statistical mechanics. Thematically organised chapters on different methodologies, contributed by key researchers using a unified notation, provide the first integrated view of the relative merits of individual approaches, aided by pertinent introductory chapters and the guidance of editorial notes.Both graduate students and established researchers wishing to understand the state of the art will greatly benefit from this comprehensive and up-to-date review of non-equilibrium and finite temperature techniques in the exciting and expanding field of quantum gases and liquids./a

Download or read book Interferometry with Interacting Bose-Einstein Condensates in a Double-Well Potential written by Tarik Berrada and published by Springer. This book was released on 2015-12-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis demonstrates a full Mach–Zehnder interferometer with interacting Bose–Einstein condensates confined on an atom chip. It relies on the coherent manipulation of atoms trapped in a magnetic double-well potential, for which the author developed a novel type of beam splitter. Particle-wave duality enables the construction of interferometers for matter waves, which complement optical interferometers in precision measurement devices, both for technological applications and fundamental tests. This requires the development of atom-optics analogues to beam splitters, phase shifters and recombiners. Particle interactions in the Bose–Einstein condensate lead to a nonlinearity, absent in photon optics. This is exploited to generate a non-classical state with reduced atom-number fluctuations inside the interferometer. This state is then used to study the interaction-induced dephasing of the quantum superposition. The resulting coherence times are found to be a factor of three longer than expected for coherent states, highlighting the potential of entanglement as a resource for quantum-enhanced metrology.

Download or read book Nature written by Sir Norman Lockyer and published by . This book was released on 2007 with total page 1692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Superfluid Phases of Helium 3 written by Dieter Vollhardt and published by Courier Corporation. This book was released on 2013-10-17 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: This classic of modern theoretical physics is the first and only comprehensive treatment of the superfluid phases of helium 3, a crucial aspect of condensed matter physics with applications to many other fields. The self-contained approach explores ideas, concepts, and theoretical results, emphasizing symmetries and the consequences of their spontaneous breakdown. 1990 edition.