Study on many-body phases in Jaynes-Cummings-Hubbard arrays

TL;DR

This paper explores how disorder affects many-body phases in Jaynes-Cummings-Hubbard arrays, revealing the emergence of many-body localization and prethermal behavior depending on disorder strength and initial states.

Contribution

It systematically investigates disorder effects in the 1D JCH model, identifying conditions for MBL, ETH violation, and prethermalization, which were previously unclear.

Findings

Strong disorder induces MBL phase in JCH arrays.

Weak disorder or coupling leads to prethermal behavior.

Disorder significantly alters thermalization properties.

Abstract

Disorder in one-dimensional (1D) many-body systems emerges abundant phases such as many-body localization (MBL), and thermalization. However, it remains unclear regarding their existence and behavior within hybrid quantum systems. Here, based on a simple bosonic-spin hybrid model, as known as the Jaynes-Cummings-Hubbard (JCH) array, we investigate the effect of disorder comparing to the phenomena in the clean system with the variation of atom-photon coupling strength. By using the level-spacing ratio, entanglement entropy, and the properties of observable diagonal and off-diagonal matrix elements, we find that strong disorder results in the appearance of MBL phase in the JCH model that strongly violate eigenstate thermalization hypothesis (ETH), while a conditional prethermal behavior can exist in weak disorder or weak coupling regime. The conditional prethermal dynamics is based on the choice of initial product states. This work systematically reveals abundant many-body phases in the 1D JCH model and clarifies the discrepancies in the thermalization properties of systems with and without disorder.