Non-Hermitian topology and non-Bloch band theory

来源:中国科学院量子信息与量子科技创新研究院发布时间:2020-12-14

报告题目Non-Hermitian topology and non-Bloch band theory
报告人汪忠 研究员
报告人单位清华大学
报告时间2020-12-18 (周五) 10:00
报告地点上海研究院4号楼329报告厅(物质楼B1102同步视频)
主办单位中国科学院量子信息与量子科技创新研究院
报告介绍

报告摘要:Non-Hermitian Hamiltonian is a widely useful language in a number of branches of physics. Intriguingly, non-Hermitian systems exhibit a unique bulk-boundary correspondence beyond the conventional framework of Bloch band theory. A revised band theory based on the generalized Brillouin zone, now known as the non-Bloch band theory, has been formulated to understand the non-Hermitian topology.  To predict the topological edge modes, topological invariants are defined in the generalized Brillouin zone rather than in the standard Brillouin zone. The consequences of non-Bloch band theory are not limited to non-Hermitian topology.  We show that this theory has a natural application to nonreciprocal amplification, a phenomenon that waves are amplified in a preferred propagation direction while suppressed in the reversed direction. Compact formulas for the gain and directionality of nonreciprocal amplifiers are obtained from the non-Bloch band theory.
References:
[1] S. Yao, Z. Wang, Phys. Rev. Lett. 121, 086803 (2018);
[2] S. Yao, F. Song, Z. Wang, Phys. Rev. Lett. 121, 136802 (2018);
[3] F. Song, S. Yao, Z. Wang, Phys. Rev. Lett. 123, 170401 (2019);
[4] Lei Xiao, et al.  Nat. Phys. 16, 761 (2020);
[5] W.-T. Xue, M.-R. Li, Y.-M. Hu, F. Song, Z. Wang, arXiv:2004.09529
报告人简介:
Zhong Wang finished his undergraduate education (2001-2005) and then got the doctorate (2011) from University of Science and Technology of China. During 2009-2010 he was a visiting student in Stanford University. He joined Institute for Advanced Study of Tsinghua Univeristy in 2011 as an associate member; he is now a member there. His current research interests include topological phases and topological phenomena in condensed matters, non-Hermitian physics, classical and quantum open systems, and strongly correlated systems.

 

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