Magnetic control of the non-Hermitian skin effect in two-dimensional lattices

The non-Hermitian skin effect (NHSE)—the anomalous boundary accumulation of an extensive number of bulk modes—has emerged as a hallmark of non-Hermitian physics, with broad implications for transport, sensing, and topological classification. A central open question is how magnetic or synthetic gauge...

Descripción completa

Detalles Bibliográficos
Autor: Longhi, Stefano
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/423067
Acceso en línea:http://hdl.handle.net/10261/423067
Access Level:acceso abierto
Palabra clave:Anderson localization
Landau levels
Skin effect
Non-Hermitian systems
Descripción
Sumario:The non-Hermitian skin effect (NHSE)—the anomalous boundary accumulation of an extensive number of bulk modes—has emerged as a hallmark of non-Hermitian physics, with broad implications for transport, sensing, and topological classification. A central open question is how magnetic or synthetic gauge fields influence this boundary phenomenon. Here, we develop a theoretical framework for magnetic control of the NHSE along line boundaries in two-dimensional single-band lattices. Using a non-Hermitian extension of the anisotropic Harper–Hofstadter model as a representative example, we show that magnetic fields suppress the geometric skin effect in reciprocal models, whereas skin localization can persist in nonreciprocal systems. The analysis disentangles the interplay of flux, nonreciprocity, and boundary geometry, revealing that magnetic fields mitigate or suppress the NHSE through distinct physical mechanisms—such as bulk localization via Landau or Anderson physics or the restoration of effective reciprocity. In particular, the geometry-dependent skin effect in reciprocal systems is found to be fragile against even weak magnetic fields.