The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.
On Monday, November 11th, 2024 from 11 am to 12 am we will host a seminar by Fan Yang from Stockholm University.
Anatomy of Higher-Order Non-Hermitian Skin and Boundary Modes
The anomalous bulk-boundary correspondence in non-Hermitian systems featuring an intricate interplay between skin and boundary modes has attracted enormous theoretical and experimental attention [1]. Still, in dimensions higher than one, this interplay remains much less understood. Here we provide insights from exact analytical solutions of a large class of models in any dimension, d, with open boundaries in dc ≤ d directions and by tracking their topological origin. Specifically, we show that Amoeba theory [2] accounting for the separation gaps of the bulk modes augmented with higher-dimensional generalizations of the biorthogonal polarization and the generalized Brillouin zone approaches [3] accounting for the surface gaps of boundary modes provide a comprehensive understanding of these systems.
[1] E.J. Bergholtz, J.C. Budich, and F.K. Kunst, Rev. Mod. Phys. 93, 015005 (2021).
[2] H.-Y. Wang, F. Song, and Z. Wang, Phys. Rev. X 14, 021011 (2024).
[3] F. Yang and E.J. Bergholtz, arXiv:2405.03750.