# Transition from Quantum Chaos to Localization in Spin Chains

## TL;DR

This paper investigates the transition from quantum chaos to many-body localization in spin chains, revealing system-dependent behaviors and identifying new universality classes through spectral analysis.

## Contribution

It provides a detailed study of level statistics near the self-dual point, uncovering localization transitions and novel random-matrix universality classes.

## Key findings

- Identification of localization transition in spin chains
- Discovery of non-standard random-matrix universality classes
- Spectral analysis near the self-dual point

## Abstract

Recent years have seen an increasing interest in quantum chaos and related aspects of spatially extended systems, such as spin chains. However, the results are strongly system dependent, generic approaches suggest the presence of many-body localization while analytical calculations for certain system classes, here referred to as the ``self-dual case'', prove adherence to universal (chaotic) spectral behavior. We address these issues studying the level statistics in the vicinity of the latter case, thereby revealing transitions to many-body localization as well as the appearance of several non-standard random-matrix universality classes.