Emergent Hydrodynamics in Integrable Quantum Systems Out of Equilibrium

• Main Authors: Olalla A. Castro-Alvaredo, Benjamin Doyon, Takato Yoshimura
• Format: Article
• Language: English
• Published: American Physical Society 2016-12-01
• Series: Physical Review X
• Online Access: http://doi.org/10.1103/PhysRevX.6.041065

Understanding the general principles underlying strongly interacting quantum states out of equilibrium is one of the most important tasks of current theoretical physics. With experiments accessing the intricate dynamics of many-body quantum systems, it is paramount to develop powerful methods that encode the emergent physics. Up to now, the strong dichotomy observed between integrable and nonintegrable evolutions made an overarching theory difficult to build, especially for transport phenomena where space-time profiles are drastically different. We present a novel framework for studying transport in integrable systems: hydrodynamics with infinitely many conservation laws. This bridges the conceptual gap between integrable and nonintegrable quantum dynamics, and gives powerful tools for accurate studies of space-time profiles. We apply it to the description of energy transport between heat baths, and provide a full description of the current-carrying nonequilibrium steady state and the transition regions in a family of models including the Lieb-Liniger model of interacting Bose gases, realized in experiments.