报告人：清华大学 王亚愚教授

邀请人：郑雨军

腾讯会议号：222244934

（点击链接入会，或添加至会议列表：

https://meeting.tencent.com/s/px5R4qKlEMRX

）

报告时间：2020年11月20日 19：00---21：00

报告人简介：

王亚愚，1998年本科毕业于中国科大物理系，2004年在普林斯顿大学物理系获博士学位，2004至2007年在加州大学伯克利分校做博士后。2007年12月加入清华大学物理系任教，现任清华大学物理系主任，低维量子物理国家重点实验室主任。主要研究方向为低维量子材料的输运性质和扫描隧道显微学研究。曾获William McMillan Award 、教育部“长江学者”、国家杰出青年基金、中国物理学会“黄昆物理奖”、国家自然科学一等奖（第二完成人）、腾讯“科学探索奖”等。

内容简介：

Quantum Transport Phenomena in Magnetic Topological Insulators

Yayu Wang

Department of Physics, Tsinghua University, Beijing 100084, China

A remarkable breakthrough in the field of topological quantum matter is the discovery of topological insulator (TI) with nontrivial bulk band topology and metallic boundary states. The TIs are expected to host a rich variety of novel quantum transport phenomena, especially when the time reversal symmetry is broken. In particular, the quantum anomalous Hall effect (QAHE), namely the quantum Hall effect in zero magnetic field, may occur in two-dimensional ferromagnetic TIs without Landau levels. In order to realize this effect, the system must fulfill the stringent requirements of being topological, ferromagnetic, and insulating simultaneously. In this talk, we will first give a brief introduction about TI and the QAHE. Then we will show how to fine tune the electronic and magnetic properties in Cr doped (Bi,Se)₂Te₃ topological insulator thin films grown by molecular beam epitaxy, which eventually led to the observation of QAHE. More recently, we investigate the quantum transport phenomena in the newly discovered MnBi₂Te₄ antiferromagnetic TI. We find the existence of robust axion insulator phase and its quantum phase transition to the Chern insulator phase in thin flakes with even number of magnetic layers. In ultrahigh magnetic field, a novel type of quantum Hall effect named helical Chern insulator phase emerges due to the Zeeman-effect-induced topological phase transition. These results demonstrate the rich topological phases and phase transitions in magnetic TIs.

热情欢迎各位老师和同学参加！