The highly complicated nature of far from equilibrium systems can lead to a complete breakdown of the physical intuition developed in equilibrium. A famous example of this is the Mpemba effect, which states that non-equilibrium states may relax faster when they are further from equilibrium or, put another way, hot water can freeze faster than warm water. Despite possessing a storied history, the precise criteria and mechanisms underpinning this phenomenon are still not known. Here we study a quantum version of the Mpemba effect that takes place in closed many body systems with a U(1) conserved charge: in certain cases a more asymmetric initial configuration relaxes and restores the symmetry faster than a more symmetric one. In contrast to the classical case, we establish the criteria for this to occur in arbitrary integrable quantum systems using the recently introduced entanglement asymmetry. We describe the quantum Mpemba effect in such systems and relate properties of the initial state, specifically its charge fluctuations, to the criteria for its occurrence. These criteria are expounded using exact analytic and numerical techniques in several examples, a free fermion model, the Rule 54 cellular automaton, and the Lieb-Liniger model.
Macroscopic Thermodynamic Framework for the Mpemba Effect
School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）；Key Laboratory of Multiscale Spin Physics (Beijing Normal University), Ministry of Education（教育部多尺度自旋物理重点实验室（北京师范大学））
Quantum Many-Body Mpemba Effect through Ruelle-Pollicott Resonances
The University of Electro-Communications（电气通信大学）；RIKEN Pioneering Research Institute (PRI)（理化学研究所先导研究本部）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所交叉理论与数学科学中心）
Exact prefactors in static and dynamic correlation functions of 1D quantum integrable models: applications to the Calogero-Sutherland, Lieb-Liniger and XXZ models
Periodic orbits and quantum many-body scars in integrable spin chains
Institute of Science and Technology Austria (ISTA)（奥地利科学技术研究所）；Technical University of Munich（慕尼黑工业大学）；Munich Center for Quantum Science and Technology (MCQST)（慕尼黑量子科学与技术中心）
Generalised BBGKY hierarchy for near-integrable dynamics
Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, CY Cergy Paris Université（理论与建模物理实验室，法国国家科学研究中心联合研究实验室8089，塞吉巴黎大学）；Faculty of Physics, University of Warsaw（华沙大学物理学院）
Kardar-Parisi-Zhang superdiffusion in chaotic quantum circuits
University of Ljubljana（卢布尔雅那大学）；King’s College London（伦敦国王学院）；Laboratoire de Physique de l’École Normale Superieure, CNRS, ENS & Université PSL, Sorbonne Université, Université Paris Cité（法国国家科学研究中心、巴黎高等师范学院、巴黎文理研究大学、索邦大学、巴黎西岱大学联合物理实验室）
