Spectral Properties of Disordered Interacting Non-Hermitian Systems

TL;DR

This paper investigates the spectral properties and chaos indicators of disordered non-Hermitian quantum systems using spectral form factors and complex spacing ratios, revealing transitions from correlated to Poisson statistics with increasing disorder.

Contribution

It introduces a detailed analysis of spectral statistics in non-Hermitian disordered models, connecting them with non-Hermitian Random Matrix Theory across different symmetry classes.

Findings

Models show spectral correlations similar to RMT at weak disorder.

Strong disorder leads to Poisson statistics indicating localization.

Different models exhibit symmetry-dependent spectral behaviors.

Abstract

Non-hermitian systems have gained a lot of interest in recent years. However, notions of chaos and localization in such systems have not reached the same level of maturity as in the Hermitian systems. Here, we consider non-hermitian interacting disordered Hamiltonians and attempt to analyze their chaotic behavior or lack of it through the lens of the recently introduced non-hermitian analog of the spectral form factor and the complex spacing ratio. We consider three widely relevant non-hermitian models which are unique in their ways and serve as excellent platforms for such investigations. Two of the models considered are short-ranged and have different symmetries. The third model is long-ranged, whose hermitian counterpart has itself become a subject of growing interest. All these models exhibit a deep connection with the non-hermitian Random Matrix Theory of corresponding symmetry classes at relatively weak disorder. At relatively strong disorder, the models show the absence of complex eigenvalue correlation, thereby, corresponding to Poisson statistics. Our thorough analysis is expected to play a crucial role in understanding disordered open quantum systems in general.