报告时间：5月10日 周四  下午3:00

报告地点：实验室一楼会议室

报告人：汪忠 (清华大学)

报告题目： Topology of non-Hermitian energy bands

摘要：

    Hamiltonians are Hermitian in the standard quantum mechanics; nevertheless, non-Hermitian Hamiltonians provide effective descriptions of a wide variety of systems. In this talk, I will focus on the interplay between topological phases and non-Hermiticity. A key question is the bulk-boundary correspondence: What are the bulk topological invariants that determine the topological edge states? I will show that the usual formulation of topological invariants based on the Bloch Hamiltonian H(k) is revised in an unexpected way. The topological edge states are determined by the ``non-Bloch topological invariants''. In particular, the chiral edge modes of a two-dimensional non-Hermitian ``quantum Hall insulator'' is determined by the non-Bloch Chern numbers. (Reference: arXiv: 1804.04672)

编辑时间：2018-05-09 14:48:04