题 目：Intrinsic magnetic topological insulator MnBi2Te4
报告人：徐勇
清华大学
时间：2019年9月23号 星期一 下午4:00
地点：国家脉冲强磁场科学中心C204
报告摘要：
The interplay of magnetism and topology is a key research subject in condensed matter physics and material science,
which offers great opportunities to explore emerging new physics, like the quantum anomalous Hall (QAH) effect,
axion electrodynamics and Majorana fermions. However, these exotic physical effects have rarely been realized in
experiment, due to the lacking of suitable working materials. In this talk, we will present our recent findings of intrinsic
magnetic topological insulators in van der Waals layered MnBi2Te4-family materials [1-6]. The materials intrinsically
show two-dimensional (2D) ferromagnetism in the single layer and three-dimensional (3D) A type antiferromagnetism in the bulk, which could serve as a next-generation material platform for the state-of-art research. We predict extremely rich topological quantum effects with outstanding features in an experimentally
available material MnBi2Te4, including a 3D antiferromagnetic topological insulator with the long sought topological axion states, the typeII magnetic Weyl semimetal (WSM) with one pair of Weyl points, and
intrinsic QAH insulators and axion insulators. Recent theoretical and experimental progresses will be introduced.
As important progresses, we experimentally observed two exotic topological phases (i.e., axion insulator and
Chern insulator) and quantum phase transition between them in one stoichiometric crystal MnBi2Te4 at relatively
high temperature [5,6].
报告人简介：
徐勇，清华大学物理系教授。于2005年、2010年获清华大学物理学学士学位和凝聚态物理学博士学位，2010年至2013年在德国马普学会弗里茨·哈伯研究所从事博士后研究并获“洪堡学者”称号，2013年至2015年在斯坦福大学担任研究学者，2015年进入清华大学物理系。研究方向包括理论和计算凝聚态物理、第一性原理材料计算与设计、拓扑绝缘体、拓扑量子物态等，已在Nature Materials、Nature Physics、Physical Review Letters、Nano Letters等发表多篇研究论文。
