Level crossings and superradiant quantum phase transition for a two-qutrit quantum Rabi model

TL;DR

This paper investigates a two-qutrit quantum Rabi model, revealing its integrability under certain conditions and uncovering critical phenomena such as level crossings and quantum phase transitions.

Contribution

It introduces a two-qutrit extension of the quantum Rabi model, demonstrating its integrability and analytical tractability of its ground-state phase diagram.

Findings

Identification of integrability conditions for the model

Derivation of the ground-state phase diagram

Revelation of level crossings and quantum phase transitions

Abstract

A two-qutrit extension of the quantum Rabi model is studied. Despite its increased complexity, the model results to be integrable under specific, physically relevant conditions. This feature allows for the emergence of analytically tractable subdynamics. In this framework, the ground-state phase diagram can be derived, and the analysis reveals critical phenomena linked to both level crossings and quantum phase transitions.