This book presents new experimental tools and theoretical concepts of collective nonequilibrium behavior of quantum systems. The book is based on the Les Houches Summer School of August 2012, "Strongly interacting quantum systems out of equilibrium".

Over the last decade new experimental tools and theoretical concepts are providing new insights into collective nonequilibrium behavior of quantum systems. The exquisite control provided by laser trapping and cooling techniques allows us to observe the behavior of condensed bose and degenerate Fermi gases under nonequilibrium drive or after `quenches' in which a Hamiltonian parameter is suddenly or slowly changed. On the solid state front, high intensity short-time pulses and fast (femtosecond) probes allow solids to be put into highly excited states and probed before relaxation and dissipation occur. Experimental developments are matched by progress in theoretical techniques ranging from exact solutions of strongly interacting nonequilibrium models to new approaches to nonequilibrium numerics. The summer school `Strongly interacting quantum systems out of equilibrium' held at the Les Houches School of Physics as its XCIX session was designed to summarize this progress, lay out the open questions and define directions for future work. This books collects the lecture notes of the main courses given in this summer school.

This book studies the dynamics of fundamental collective excitations in quantum materials, focusing on the use of state-of-the-art ultrafast broadband optical spectroscopy. Collective behaviour in solids lies at the origin of several cooperative phenomena that can lead to profound transformations, instabilities and phase transitions. Revealing the dynamics of collective excitations is a topic of pivotal importance in contemporary condensed matter physics, as it provides information on the strength and spatial distribution of interactions and correlation. The experimental framework explored in this book relies on setting a material out-of-equilibrium by an ultrashort laser pulse and monitoring the photo-induced changes in its optical properties over a broad spectral region in the visible or deep-ultraviolet. Collective excitations (e.g. plasmons, excitons, phonons...) emerge either in the frequency domain as spectral features across the probed range, or in the time domain as coherent modes triggered by the pump pulse. Mapping the temporal evolution of these collective excitations provides access to the hierarchy of low-energy phenomena occurring in the solid during its path towards thermodynamic equilibrium. This methodology is used to investigate a number of strongly interacting and correlated materials with an increasing degree of internal complexity beyond conventional band theory.

The Julian Schwinger Centennial Conference of 2018 assembled many of Schwinger's students, colleagues, and friends to celebrate this towering figure of twentieth century physics one hundred years after his birth. This proceedings volume collects talks delivered on this occasion. They cover a wide range of topics, all related to Schwinger's rich scientific legacy — supplemented by personal recollections about Julian Schwinger, the physicist, the teacher, and the gentleman.Also included are an essay of 1985, co-authored by Schwinger but not published previously, as well as the transcripts of speeches by distinguished colleagues at the 1978 gathering when Schwinger's sixtieth birthday was celebrated.

This book addresses the needs of growing community of graduate students and researchers new to the area, for a survey that covers a wide range of pertinent topics, summarizes the current status of the field, and provides the necessary pedagogical materials for newcomers. The investigation of strongly interacting matter under the influence of macroscopic rotational motion is a new, emerging area of research that encompasses a broad range of conventional physics disciplines such as nuclear physics, astrophysics, and condensed matter physics, where the non-trivial interplay between global rotation and spin is generating many novel phenomena. Edited and authored by leading researchers in the field, this book covers the following topics: thermodynamics and equilibrium distribution of rotating matter; quantum field theory and rotation; phase structure of QCD matter under rotation; kinetic theory of relativistic rotating matter; hydrodynamics with spin; magnetic effects in fluid systems with high vorticity and charge; polarization measurements in heavy ion collisions; hydrodynamic modeling of the QCD plasma and polarization calculation in relativistic heavy ion collisions; chiral vortical effect; rotational effects and related topics in neutron stars and condensed matter systems.

This 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.

Quantum field theory is the application of quantum mechanics to systems with infinitely many degrees of freedom. This 2007 textbook presents quantum field theoretical applications to systems out of equilibrium. It introduces the real-time approach to non-equilibrium statistical mechanics and the quantum field theory of non-equilibrium states in general. It offers two ways of learning how to study non-equilibrium states of many-body systems: the mathematical canonical way and an easy intuitive way using Feynman diagrams. The latter provides an easy introduction to the powerful functional methods of field theory, and the use of Feynman diagrams to study classical stochastic dynamics is considered in detail. The developed real-time technique is applied to study numerous phenomena in many-body systems. Complete with numerous exercises to aid self-study, this textbook is suitable for graduate students in statistical mechanics and condensed matter physics.