报告人：徐勇 副教授 (清华大学交叉信息研究院)

时 间：2024年5月23号（周四） 15：00-17：00

地 点：良乡校区，物理实验楼229会议室

摘要：In recent years, higher-order topological phases have attracted great interest in various fields of physics. These phases have protected boundary states at lower-dimensional boundaries than the conventional first-order topological phases due to the higher-order bulk-boundary correspondence. In this talk, I will first give a brief introduction to how a higher-order topology appears and then discuss the effects of disorder on the quadrupole insulator. I will also show how non-crystalline lattices in two dimensions, such as quasicrystalline lattices, amorphous lattices and hyperbolic lattices, can give rise to topological phases without crystalline counterparts. I will further talk about higher-order topological phases in three-dimensional amorphous lattices and quasicrystalline lattices.

References:

1. Y.-B. Yang, J.-H. Wang, K. Li, and Y. Xu, Higher-order topological phases in crystalline and non-crystalline systems: a review, J. Phys.: Condens. Matter 36 (2024) 283002.

2. Y.-B. Yang, K. Li, L.-M. Duan, and Y Xu, Higher-order topological Anderson insulators, Phys. Rev. B 103, 085408 (2021).

3. Y.-L. Tao and Y. Xu, Higher-order Topological Hyperbolic Lattices, Phys. Rev. B 107, 184201 (2023).

4. Y.-L. Tao, J.-H. Wang, and Y. Xu, Average Symmetry Protected Higher-order Topological Amorphous Insulators, SciPost Phys. 15, 193 (2023).

5. J.-H. Wang, Y.-B. Yang, N. Dai, and Y. Xu, Structural Disorder Induced Second-order Topological Insulators in Three Dimensions, Phys. Rev. Lett. 126, 206404 (2021).

6. Y.-F. Mao, Y.-L. Tao, J.-H. Wang, Q.-B. Zeng, and Y. Xu, Higher-order Topological Insulators and Semimetals in Three Dimensions without Crystalline Counterparts, Phys. Rev. B 109, 134205 (2024).

简历：徐勇，清华大学交叉信息研究院长聘副教授。2005年本科毕业于兰州大学物理科学与技术学院，2013年在中科院物理研究所获得博士学位，先后在美国德克萨斯大学达拉斯分校和美国密歇根大学安娜堡分校从事博士后研究。2017年9月任清华大学交叉信息研究院助理教授，2023年6月晋升为长聘副教授。主要从事冷原子新奇量子物态的理论研究，提出了有结构的（第二类）外尔费米子、外尔奇异环等概念，多项理论预言被实验证实。

联系方式：ccliu @bit.edu.cn

邀请人： 刘铖铖

网 址：http:/

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