KITS-IOP-ITP Joint Seminar

Title: Higher-order topology in quasicrystalline and magnonic systems

Speaker: Prof. Dong-Hui Xu (Chongqing University)
Time: Jan. 23 (Tuesday), 10:00
Place: Rm M830, IOP-CAS

Abstract: 
Recent research has seen a surge of interest in topological phases with higher-order topology, an extension of well-established topological phases in various physics domains. These phases exhibit unconventional gapless boundary states, including corner and hinge states, surpassing the conventional bulk-boundary correspondence principle in topological matter. While higher-order topology has been recognized in both gapped and gapless systems, it has been predominantly explored within crystal structures. In this talk, I will provide a concise overview of first-order and higher-order topological phases before delving into our recent investigations on higher-order topology within aperiodic quasicrystals. Our findings reveal a novel category of higher-order topological phases protected by rotational symmetries that are impossible in regular crystals, like eightfold or twelvefold rotational symmetries. Additionally, I will talk about our exploration of higher-order topological phases in twisted bilayer honeycomb magnets.
Refs.: [1] Rui Chen et al. Phys. Rev. Lett. 124, 036803 (2020).
[2] Chun-Bo Hua et al. Phys. Rev. B 102, 241102(R) (2020). 
[3] Rui Chen et al. Phys. Rev. B 108, 195306 (2023).
[4] Chun-Bo Hua et al. Phys. Rev. B 107, L020404 (2023).

Short bio: 许东辉，重庆大学教授，2012年毕业于浙江大学获博士学位，2012-2016年先后在浙江大学、香港科技大学从事博士后研究工作，2016-2022年在湖北大学任副教授，2022年加入重庆大学。从事凝聚态理论研究，主要研究方向为：拓扑量子物态、超导和磁性。在美国物理学会Physical Review Letters, Physical Review A/B期刊发表上述方向研究论文50余篇。

More details can be found in http://seminar.cpsjournals.cn/