报告人：姜天舒博士 (香港科技大学)

时 间：2021年9月6日20:00-22:00

腾讯会议 ID：425 913 262

摘要：

Topological phases protected by various symmetries have interested researchers enormously. They all can be described by topological charges taking quantized values, i.e. the integer group . Very recently, increasing attention has been focused on the non-Abelian topological charges, i.e. the quaternion group . Being different from the Abelian topological band insulators, these systems involve two more tangled bulk bandgaps and support non-trivial edge states that inherit the non-Abelian topological features. Furthermore, a system with even or odd number of bands will exhibit huge difference in topological charge classifications.

In this talk, I will mainly talk about the studies of non-Abelian topological insulators realized in transmission line networks. We both theoretically explored and experimentally realized 3-band and 4-band PT (inversion and time-reversal) symmetric systems. In the 3-band system study, the quaternion-valued non-Abelian topological charges are clearly mapped onto an eigenstate-frame sphere. Moreover, we find a non-Abelian quotient relation that provides a global perspective on the distribution of edge/domain-wall states. In the 4-band system study, two new classes of topological charges as well as edge states are comprehensively studied. We illustrate their difference from four-dimensional rotation. We show the evolution of bulk topology by extending the 1D Hamiltonian onto a 2D plane and provide the accompanying edge state distributions following an analytical method.

简历：

Dr. Tianshu Jiang is currently a visiting scholar at Hong Kong University of Science and Technology (HKUST). After getting a bachelor's degree from the University of Science and Technology of China (USTC) in 2014, he joined the group of Prof. Che Ting Chan’s group at HKUST as a Ph.D. student and graduated in 2020. His high-level publications include Nature, Nat. Commun., Light Sci. Appl., Nanophotonics, etc.

联系方式：cuicuilu@bit.edu.cn

邀请人：路翠翠

网 址：/

承办单位：物理学院、先进光电量子结构设计与测量教育部重点实验室