2019/01/31 by Mário G. Silveirinha
Mathematics · Physics and Astronomy · #Chern class #Complex plane #Condensed matter physics #Function (biology) #Gapless playback #Hermitian matrix #Mathematical analysis #Mathematics #Nonlinear Photonic Systems #Physics #Pure mathematics #Quantum Mechanics and Non-Hermitian Physics #Quantum mechanics #Topological Materials and Phenomena #Topology (electrical circuits) #physics.optics
paper · pdf · doi:10.1103/physrevb.99.125155
published as Phys. Rev. B 99, 125155 (2019) · 44 pages, accepted for publication in Phys. Rev. B
arxiv created 2019/03/05 · openalex publication_date 2019/03/29 · arxiv updated 2019/04/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recently, it was shown that non-Hermitian systems, e.g., materials with loss or gain, can have topological properties. Here, the author develops a gauge-independent Green's function approach to classify the topological phases of generic non-Hermitian systems. The proposed theory introduces in a natural way the band gaps of non-Hermitian systems as the strips of the complex-frequency plane, wherein the Green's function is analytical, and unveils that the spectrum of a non-Hermitian topological material cavity terminated with opaque-type walls must be gapless.