Dynamical localization transition in the non-Hermitian lattice gauge theory

TL;DR

This paper studies the nonequilibrium dynamics of a non-Hermitian lattice gauge theory, revealing localization transitions, skin effects, and quantum information flow, with implications for quantum simulation experiments.

Contribution

It introduces a duality mapping to analyze non-Hermitian effects in lattice gauge theories, uncovering new localization phenomena and quantum disentangled liquids.

Findings

Identification of localization-delocalization transition in non-Hermitian gauge systems.

Discovery of non-Hermitian skin effect influencing quantum information flow.

Proposal of non-Hermitian quantum disentangled liquids in different phases.

Abstract

Local constraint in the lattice gauge theory provides an exotic mechanism that facilitates the disorder-free localization. However, the understanding of nonequilibrium dynamics in the non-Hermitian lattice gauge model remains limited. Here, we investigate the quench dynamics in a system of spinless fermions with nonreciprocal hopping in the $\mathbb{Z}_2$ gauge field. By employing a duality mapping, we systematically explore the non-Hermitian skin effect, localization-delocalization transition, and real-complex transition. Through the identification of diverse scaling behaviors of quantum mutual information for fermions and spins, we propose that the non-Hermitian quantum disentangled liquids exist both in the localized and delocalized phases, the former originates from the $\mathbb{Z}_2$ gauge field and the latter arises from the non-Hermitian skin effect. Furthermore, we demonstrate that the nonreciprocal dissipation causes the flow of quantum information. Our results provide valuable insights into the nonequilibrium dynamics in the gauge field, and may be experimentally validated using quantum simulators.