# Superradiance in finite quantum systems randomly coupled to continuum

## TL;DR

This paper investigates superradiance in finite open quantum systems with random couplings, revealing how decay properties and exceptional points influence the phenomenon, especially near quantum criticality.

## Contribution

It introduces a comprehensive analysis of superradiance using random matrix theory and links the effect to the distribution of exceptional points and quantum criticality.

## Key findings

- Superradiance is enhanced at quantum critical points.
- Eigenstates separate into short- and long-living due to increasing decay widths.
- Robust features are related to the distribution of exceptional points.

## Abstract

We study the effect of superradiance in open quantum systems, i.e., the separation of short- and long-living eigenstates when a certain subspace of states in the Hilbert space acquires an increasing decay width. We use several Hamiltonian forms of the initial closed system and generate their coupling to continuum by means of the random matrix theory. We average the results over a large number of statistical realizations of an effective non-Hermitian Hamiltonian and relate robust features of the superradiance process to the distribution of its exceptional points. We show that the superradiance effect is enhanced if the initial system is at the point of quantum criticality.