We review various bounds concerning out-of-equilibrium dynamics in few-level and many-body quantum systems. We primarily focus on closed quantum systems but will also mention some related results for open quantum systems and classical stochastic systems. We start from the speed limits, the universal bounds on the speeds of (either quantum or classical) dynamical evolutions. We then turn to review the bounds that address how good and how long would a quantum system equilibrate or thermalize. Afterward, we focus on the stringent constraint set by locality in many-body systems, rigorously formalized as the Lieb-Robinson bound. We also review the bounds related to the dynamics of entanglement, a genuine quantum property. Apart from some other miscellaneous topics, several notable error bounds for approximated quantum dynamics are discussed. While far from comprehensive, this topical review covers a considerable amount of recent progress and thus could hopefully serve as a convenient starting point and up-to-date guidance for interested readers.
Exact nonequilibrium steady states of boundary driven circuit with XYZ gates
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所凝聚态物理国家实验室);Faculty of Mathematics and Physics, University of Ljubljana(卢布尔雅那大学数学与物理学院);Institute of Mathematics, Physics and Mechanics(数学、物理和力学研究所);Department of Physics, University of Wuppertal(伍珀塔尔大学物理系)
Exact methods in analysis of nonequilibrium dynamics of integrable models: application to the study of correlation functions in nonequilibrium 1D Bose gas
Nonequilibrium dynamics in the one-dimensional Fermi-Hubbard model: A comparison of the nonequilibrium Green functions approach and the density matrix renormalization group method
格点系统中强关联费米子的非平衡动力学在凝聚态和超冷原子-气体社区中引起了相当大的兴趣。虽然近年来实验取得了显着的进展,但仍然需要进一步发展理论工具,以解释非平衡条件和强相关性。例如,基于密度矩阵重整化群(DMRG)方法的时间相关理论量子方法主要应用于一维设置。最近,已经提出了基于非平衡格林函数(NEGF)的费米子膨胀的二维量子模拟[Schluenzen等人,Phys. Rev. B 93,035107(2016)],其显示出与实验的极好一致性。在这里,我们提出了一个广泛的比较NEGF的方法,数值准确的DMRG结果。结果表明,NEGF是一个可靠的理论工具,在任意尺寸的弱到中等耦合强度,并使长时间的模拟成为可能。这是对DMRG模拟的补充,DMRG模拟在强耦合时特别有效。