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BIMSA-Tsinghua可计算离散整体几何结构、拓扑材料和量子计算机讨论班
The "spectral topology" and skin effect in non-Hermitian band theory
The "spectral topology" and skin effect in non-Hermitian band theory
组织者
刘正伟
, 丘成桐
, 赵辉
演讲者
方辰
时间
2022年03月10日 14:00 至 15:15
地点
JCY-1
摘要
In non-Hermitian bands, eigenvalues of the Hamiltonian become complex. The phase of the complex eigenvalue endows a new type of topology unique to non-Hermitian band theory, the spectral topology, describing the winding of the phase as the momentum goes along a loop in momentum space. In this talk, I show a special bulk-edge correspondence restricted to non-Hermitian bands: the spectral topology under periodic-boundary condition maps to the skin effect under open boundary condition. An algebraic method for quantifying the skin effect is introduced in 1D, and qualitative results on 2D and higher dimensions are also discussed.
[1] K. Zhang, Z. Yang*, and C. Fang, arXiv:2102.05059 (2021)
[2] K. Zhang, Z. Yang, and C. Fang, Phys. Rev. Lett. 125, 126402 (2020)
[3] Z. Yang, K. Zhang, C. Fang, and J. Hu, Phys. Rev. Lett. 125, 226402 (2020)
演讲者介绍
方辰研究员于2011年博士毕业于美国Purdue University,2012年到2015年间在普林斯顿大学、麻省理工学院任博士后研究助理,2015年底加入中科院物理所任副研究员,2018年任研究员。
方辰研究员是拓扑物理学中”高阶拓扑态“理论的提出者之一【Phys. Rev. Lett. 119, 246402 (2017)】,完成了绝缘体在230个空间群下的拓扑分类【Nature Communications 9, 3530 (2018)】,主持建立了首个拓扑材料计算数据库【Nature 566, 475 (2019)】。
最近,方辰研究员进入了一些新的研究方向,如非厄米能带理论和量子多体伤痕等。个人主页:http://www.iop.cas.cn/rcjy/zgjgwry/?id=2837