报告题目：Emergent topology and symmetry-breaking order in correlated quench dynamics

报告人：   刘雄军 教授（北京大学）

报告时间：2019年4月18日（周四）上午10：00

报告地点： 物理学院新楼502会议室

报告摘要：

      Quenching a quantum system involves three basic ingredients: the initial phase, the post-quench target phase, and the non-equilibrium dynamics which carries the information of the former two. In this talk I will introduce how to identify both the topology and symmetry-breaking order in a correlated system, the Haldane-Hubbard model, from quantum dynamics induced by quenching an initial magnetic phase to topologically nontrivial regime. The equation of motion for the complex pseudospin dynamics is obtained through the flow equation method, with the pseudospin evolution shown to obey a microscopic Landau-Lifshitz-Gilbert equation. We find that, with the particle-particle interaction playing crucial roles, the correlated quench dynamics exhibit robust universal behaviors on the band-inversion surfaces (BISs), from which the nontrivial topology and magnetic orders can be extracted. In particular, the topology of the post-quench regime can be characterized by an emergent dynamical topological pattern of quench dynamics on BISs, which is robust against dephasing and heating induced by interactions; the pre-quench symmetry-breaking orders can be read out from a universal scaling behavior of the quench dynamics emerging on the BIS. These results may show insights into the exploration of novel correlation physics with nontrivial topology by quench dynamics.

报告人简介：

刘雄军教授2011年博士毕业于美国德州A&M大学物理系。2011至2014年分别在美国马里兰大学凝聚态物理中心和联合量子研究所，香港科大高等研究院和麻省理工学院从事博士后研究。他于2014年9月加入北京大学量子材料科学中心任研究员。2018年7月获得终身长聘职位，次年1月晋升为终身长聘正教授。刘雄军教授长期在拓扑物相和超冷原子量子模拟领域开展研究。他在人工规范场量子模拟，拓扑超导领域做出系列原创工作；尤其推动近些年人工自旋轨道耦合、拓扑量子模拟方向的理论和实验发展。研究工作多以通讯作者或一作发表在Science，Science子刊，Nature子刊，PRL，PRX等期刊上。他目前的主要研究兴趣集中在拓扑超导，人工规范场量子模拟，非平衡拓扑量子系统，强关联拓扑物相等方面。

邀请人： 张文献 教授