主讲人单位 (Speaker's Institute): 中国科学院理论物理研究所

邀请人 (Invited by): 邓元刚

时间 (Time): 星期二,2022/06/07-10:30 to 12:00

地点 (Location): 珠海校区天琴中心2317会议室

摘要 (Abstract): 

Topological Mott insulating (TMI) state with spontaneous time-reversal symmetry breaking and nonzero Chern number has been shown to appear in a real-space effective model for twisted bilayer graphene (TBG) at 3/4 filling in the strong coupling limit. However, the dynamic and thermodynamic properties of such a TMI state remain illusive. In this work, we obtain the finite-T phase diagram and the dynamical properties of the TBG model. The phase diagram includes the quantum anomalous Hall and charge density wave phases at low T, and a phase transition of two-dimensional Ising universality separating them from the high-T symmetric phase. Our work explains the smearing of the many-electron state topology by proliferating excitons consisted of quasiparticles from bands of with opposite Chern numbers, and opens the avenue for controlled many-body investigations on finite-temperature states in the TBG and other quantum moire systems.

主讲人简介 (Speaker's CV): 

石弢，南开大学物理系学士，理论物理研究所博士，马克斯·普朗克量子光学研究所博士后。现任中国科学院理论物理研究所研究员。发表研究论文90余篇，论文引用2300余次。H-Index：26。 研究方向为：量子物理、量子信息和光与物质的相互作用理论研究。