题 目：Topological Phases in Transition Metal Chalcogenides
报告人：刘军伟
时 间：2019年8月6日 14:45
地 点：常熟理工学院东南校区求真楼T1-520室
报告摘要：The discovery of quantum spin Hall effect engendered a new chapter of topological materials research in condensed matter physics and materials science. In this talk, I will introduce some of our recent theoretical works about the topological phases in 2D and 3D transition metal chalcogenides. Based on first-principles calculations, we predict monolayer MX2 (M=Mo, W; X=S, Se, Te) of 1T’ structure could exhibit quantum spin Hall effect. Moreover, their topology can be easily tuned by external electric field, which motivated us to propose a new type of transistor, called topological field transistor. More recently, we found another new class of transition metal chalcogenides MM’Te4 (M=Nb, Ta; M’=Ir, Rh) could be quantum spin Hall insulators in 2D and Weyl semimetals in 3D. I will also discuss some recent transport, ARPES and STM experiments on monolayer WTe2, where many of the observations are consistent with monolayer WTe2 being a 2D TI.
Keywords: WTe2, quantum spin Hall insulator, transition metal chalcogenides
References:
[1] X. Qian, J. Liu, L. Fu, J. Li，Science 346, 1344 (2014)
[2] J. Liu, H. Wang, C. Fang, L. Fu, X. Qian, Nano Lett. 17 467-475 (2017)
报告人简介：
刘军伟，教授，2014年博士毕业于清华大学物理系，之后在麻省理工学院做博士后研究。2017年加入香港科技大学任助理教授。他的研究兴趣十分广泛，主要集中在以下几个方面：1）包括拓扑绝缘体，量子反常霍尔效应，拓扑晶体绝缘体和拓扑半金属在内的拓扑材料计算和预测；2）强关联系统的量子蒙特卡洛模拟；3）原子级厚度的铁电材料已经有相应的物理应用；4）二维量子材料和现象。迄今为止，已经在高水平杂志上发表多篇文章，包括2篇Science，2篇Nature Materials, 1篇Nature Physics, 2篇Nature Communications, 2篇Nano Letters 和1篇Physical Review Letters。总SCI被引次数2400+， H因子20。
