报告题目：Topological Quantum Materials and Others

报告人：沈顺清 教授（香港大学物理系）

报告时间：11月30日下午16：00-17：00

报告地点：物理学院新楼五楼大报告厅

报告摘要：Topology is an old branch of mathematics, and is now becoming an efficient to discover new phases of matter. In the last decade, prediction and discovery of topological insulators and other materials is the most significant progress in condensed matter physics and material sciences on topological matericals. Topological insulator is an insulator that always has a metallic boundary. These metallic boundaries originate from the topology of the band structure of solids, which is insensitive to the geometry of system and cannot change as long as the material remains insulating. The first topological state of matter is the quantum Hall state, the Hall conductance of which is insensitive to continuous changes in the parameters and depends only on the number of edge states, which are unidirectional because of the breaking of the time reversal symmetry due to the magnetic field. This effect was generalized to the system with time reversal symmetry, such as graphene with spin orbit coupling and an "inverted" semiconductor HgTe/CdTe quantum well, exhibiting the phenomenon of the quantum spin Hall effect. The new state has been generalized from two dimensions to three dimensions and one dimension, from insulator to superconductors, semimetals and other systems such as photonic crystals, metamaterials and even classical mechanics.

In this talk I first present an introduction to topological phases of matter and recent progresses especially on topological superconductors and topological Weyl semimetal. A simple but unified description for a large family of topological phases of matter based is presented based on a modified Dirac equation.

报告人简介:

沈顺清教授博士毕业于复旦大学理论物理专业，1992-1995年在中国高等科学技术中心做博士后，1995-1997年被马普复杂物理系统研究所聘为研究员，1997年被日本东京工业大学聘为研究员。1997年12月至今，一直在香港大学物理系工作。 沈顺清教授一直致力于凝聚态物理理论研究，特别是强关联电子体系，过渡金属氧化物，量子磁性，半导体自旋电子学，和拓扑绝缘体，拓扑半金属等。2012年他为斯普林格出版社固体科学系列丛书写的《拓扑绝缘体》是目前拓扑绝缘体方面的一本专著。

邀请人：徐红星教授