Noise-Induced Resurrection of Dynamical Skin Effects in Quasiperiodic Non-Hermitian Systems

TL;DR

This paper demonstrates that Ornstein-Uhlenbeck noise can unexpectedly revive the dynamical skin effect in quasiperiodic non-Hermitian systems, enabling delocalization and directional transport despite strong localization tendencies.

Contribution

It reveals a novel noise-induced mechanism that restores the dynamical skin effect by transforming the system dynamics into a non-reciprocal master equation with a noise-induced point gap.

Findings

Noise restores the dynamical skin effect in localized regimes.

Noise induces a non-reciprocal master equation with a complex spectrum.

Relaxation dynamics depend non-monotonically on noise strength.

Abstract

The non-Hermitian skin effect (NHSE) refers to the accumulation of an extensive number of eigenstates at system boundaries under open boundary conditions (OBCs). As a dynamical consequence, wave packets in such systems drift and ultimately accumulate at a boundary, giving rise to the dynamical skin effect (DSE). While strong quasiperiodic potentials are known to suppress the DSE by inducing localization, we show that the introduction of Ornstein-Uhlenbeck (OU) noise unexpectedly restores it. Using perturbative analysis, we demonstrate that noise effectively maps the non-Hermitian Schr\"{o}dinger dynamics onto a non-reciprocal master equation, whose complex spectrum develops a noise-induced point gap. This mechanism enables delocalization, reinstates directional transport, and revives the DSE even in regimes where the static NHSE is absent. Moreover, the relaxation dynamics exhibit a non-monotonic dependence on noise strength, reflecting a competition between noise-assisted delocalization and noise-induced decoherence. Our results uncover a noise-enabled mechanism for resurrecting the DSE and suggest a new route for controlling transport in quasiperiodic, open quantum systems.