Gauge field induced skin effect in spinful non-Hermitian systems
Phys. Rev. B 112, 125149 – Published 22 September, 2025
DOI: https://doi.org/10.1103/vhz9-xwf4
Abstract
The non-Hermitian skin effect (NHSE), a hallmark of non-Hermitian systems, stems from the topological nature of complex energy spectra, typically characterized by a nonzero spectral winding number. Beyond the spinless frameworks considered so far, here we realize a generic, tunable spinful NHSE in a one-dimensional (1D) tight-binding lattice endowed with spin-dependent Abelian gauge fields. With proper tuning of the gauge parameter, we uncover an emergence of bidirected, spin-polarized zero-winding skin states, appearing in the absence of transpose-type time-reversal symmetry () and featuring scale-restricted localization with non-Bloch spectral stability. While clearly distinct from the known and critical NHSEs, these unconventional skin states evolve into them upon enforcing and introducing interspin coupling via magnetic fields, respectively. The magnetic field further drives a transition from a bidirectional to a unidirectional skin configuration. Our work unifies the previously known zero-winding NHSEs within a broader framework and provides experimentally accessible routes for realization in photonic and ultracold atomic systems with synthetic gauge fields.