Unidirectional-like edge transport induced by non-Hermitian skin effects
Phys. Rev. B 114, 125101 – Published 3 August, 2026
DOI: https://doi.org/10.1103/py79-87yv
Abstract
Non-Hermitian skin effects (NHSEs) enable dramatic boundary accumulation of waves, yet their experimental realization typically demands engineered nonreciprocity or spatially patterned loss. Here we demonstrate theoretically and experimentally that uniform loss provides a simple and previously overlooked mechanism for enforcing unidirectional-like edge transport in photonic crystals that breaks time-reversal symmetry in the presence of nonchiral edge states. Using a core-cladding geometry where domains share identical Chern numbers but possess distinct bulk polarizations, we show that uniform loss activates NHSEs that reshape the spectral topology of edge bands, giving rise to point-gap windings that dictate a one-way propagation. Near-field measurements confirm that loss converts intrinsically bidirectional interface states into a unidirectional-like circulation around the entire domain wall, showing excellent agreement with theory. Our results establish uniform loss as a universal and structurally simple route for achieving unidirectional-like wave transport.
