应材料学院李洋副教授邀请，安徽大学量子材料与物理研究所李惠教授将来我校进行交流访问，将在低维纳米材料电输运测量方面带来相关报告，欢迎感兴趣的师生参加。

报告人：李惠 教授

报告题目：Quantitative analysis of weak antilocalization effect of topological surface states in topological insulator BiSbTeSe₂

报告时间/地点：11月10日，材料学院522室，上午9：00

Abstract：In topological insulators, the electrons’ spin in topological surface states (TSS) is locked to its momentum, which gives rise to a non-trivial  Berry phase after completing a time-reversed self-intersecting path adiabatically in the quantum diffusion regime. This non-trivial Berry phase could lead to quantum correction to the classical electronic conductivity in low magnetic fields, manifesting itself as a weak antilocalization (WAL) effect. Quantitative analysis of the WAL effect of TSS in topological insulators is of tremendous importance as it provides a strategic way to insight into the topological properties of the TSS. The major obstacle to achieve accurate results is how to eliminate the contribution of the anisotropic magnetoconductance of bulk states when the Fermi level lies in bulk bands. In this talk I will introduce an alternative approach for the quantitative analysis of the WAL effect of TSS in a more accurate way by measuring anisotropic magnetoconductance of topological insulator BiSbTeSe₂ (BSTS). The anomalous conductance peaks in the parallel orientations are observed in anisotropic magnetoconductance curves, which are originated from the WAL effect of TSS of BSTS. By subtracting the anisotropic magnetoconductance of bulk states, the WAL effect of topological surface states can be well described by the Hikami-Larkin-Nagaoka expression. Our findings offer an alternative avenue for the quantitative exploration of the WAL effect of TSS in topological insulators.

报告人简介：李惠，安徽大学教授。2014年获中国科学技术大学凝聚态物理学博士，同年9月前往香港科技大学做博士后研究，2018年12月加入安徽大学物质科学与信息技术研究院量子材料与物理研究所。长期从事低维材料生长和磁电物性调控方面的研究，在拓扑量子材料、二维材料等研究方向取得了一系列有一定影响力的研究成果。以第一作者在Nature Communications、Nano Letters、Physical Review B、Physical Review Materials、Applied Physics Letters等期刊发表SCI论文20余篇，其中2篇论文被遴选为ESI高被引文章。2019年获第21届半导体、光电子、纳米结构电子动力学国际会议（EDISON 21） “青年研究者奖”（Young Researcher Award）。