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. Still, in dimensions higher than one, this interplay remains much less understood. Here we provide insig...

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Bibliographic Details
Main Authors: Fan Yang, Emil J. Bergholtz
Format: Article
Language:English
Published: American Physical Society 2025-06-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.023233
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Summary: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. 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 d_{c}≤d directions, and by tracking their topological origin. Specifically, we show that amoeba theory accounting for the separation gaps of the bulk modes augmented with higher-dimensional generalizations of the biorthogonal polarization and the generalized Brillouin zone approaches accounting for the surface gaps of boundary modes provide a comprehensive understanding of these systems.
ISSN:2643-1564