Quantum dynamical signatures of non-Hermitian boundary modes

TL;DR

This paper investigates the quantum dynamical signatures of non-Hermitian boundary modes, providing experimental criteria and identifying observable effects related to boundary phenomena in non-Hermitian systems.

Contribution

It introduces experimentally accessible signatures of boundary modes and establishes criteria to distinguish bulk and boundary effects via the generalized Brillouin zone.

Findings

Boundary modes produce distinct dynamical signatures.

Criteria for detecting boundary effects using the Liouvillian gap.

Signatures identified in both stable and unstable regimes.

Abstract

The non-Hermitian bulk-boundary correspondence features an interplay between the non-Hermitian skin effect and anomalous boundary-mode behavior. Whereas the skin effect is known to manifest itself in quantum dynamics in the form of chiral damping, it has remained less clear what impact the boundary modes may have. Here we derive experimentally accessible signatures of the boundary modes. We also establish clear criteria, based on the effective generalized Brillouin zone, that determine when bulk and boundary effects can be dynamically discerned using the Liouvillian separation gap. This leads to telltale signatures in both stable regimes -- where particle number remains finite -- and in the unstable regimes -- where a macroscopic boundary mode population occurs.