报告题目 (Title)：First-principles material design of magnetic topological insulators（磁性拓扑绝缘体的第一性原理材料设计）
报告人 (Speaker)：Dr. Arthur Ernst（Johannes Kepler Universität Linz, Max-Planck-Institut für Mikrostrukturphysik）
报告时间 (Time)：2024年4月2日(周二) 9:30
报告地点 (Place)：校本部 E106
邀请人 (Inviter)：任伟 教授
主办部门：量子科技研究院/永利物理系
摘要 (Abstract)：
It is a well known fact that a magnetic field can break the time reversal symmetry and therewith can destroy a topologically protected surface state in topological insulators. However, the interplay between magnetism and topological order can yield a number of interesting phenomena such as the quantum anomalous Hall effect, a topological magneto-electric effect, and quantised Kerr- or Faraday rotation. This motivates researcher for a search of new magnetic topological insulators and for an intensive study of their electronic and magnetic properties. In my talk, I’ll give an overview of our first-principles investigations on this class of materials. In the first part, I’ll present shortly a method and approximations used in our simulations and then talk about several examples of magnetic topological insulators, studied in our group within the last years. First of all, I’ll discuss topological insulators doped with magnetic impurities, which can imply various magnetic order in these materials. A special attention will be devoted to the exchange interaction between magnetic impurities and to the impact of electron-magnon interaction on the electronic structure in some doped topological systems. As next, I’ll demonstrate how some defects or impurities without magnetic moments can induce magnetism in topological insulators and discuss the main features of magnetic interactions in these systems.
