內容：

Topological phase of matter is a main stream of research in condensed matter physics, with the characterization having been mainly developed based on equilibrium theory. In comparison, non-equilibrium dynamics induced by quenching a quantum system may carry information of both the initial phase and post-quench target phase. In this talk I will introduce how to characterize topological quantum phases by far-from-equilibrium quantum dynamics induced by quench, and further explore dynamically both the topology and symmetry-breaking order in correlated topological system. In free-fermion topological phases, we show a dynamical bulk-surface correspondence relates the dD bulk topology to dynamical topological pattern emerging in the (d-1)D band-inversion surfaces (BISs) in momentum space, similar to the well-known bulk-boundary correspondence in the real space. In the interacting regime, the quantum pseudospin dynamics is shown to follow a microscopic Landau-Lifshitz-Gilbert equation and exhibit robust universal behaviors on the BISs, from which the nontrivial topology and magnetic orders can be extracted. In particular, the topology can be characterized by an emergent 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.

人物介紹：

劉雄軍教授2011年博士畢業于德州A&M大學物理系。2011至2014年分別在馬里蘭大學凝聚態物理中心和聯合量子研究所，香港科大高等研究院和麻省理工學院從事博士后研究。他于2014年9月加入北京大學量子材料科學中心任研究員。2018年7月獲得終身長聘職位，同年8月獲得國家杰青資助，2019年1月晉升為正教授。劉雄軍教授長期在拓撲物相和超冷原子量子模擬領域開展研究。他在人工規范場量子模擬，拓撲超導領域做出系列工作；尤其推動近些年人工自旋軌道耦合、拓撲量子模擬方向的理論和實驗發展。研究工作多以通訊作者或一作發表在Science，Science子刊，Nature子刊，PRL，PRX等期刊上。他目前的主要研究興趣集中在拓撲超導，人工規范場量子模擬，非平衡拓撲量子系統，強關聯拓撲物相等方面。