Parity symmetry and parity breaking in the quantum Rabi model with addition of Ising interaction

TL;DR

This paper investigates how adding an Ising interaction with an extra spin can restore parity symmetry in the biased quantum Rabi model, offering a physically realistic approach and exploring experimental feasibility.

Contribution

It introduces a novel method of restoring parity symmetry in the biased quantum Rabi model by involving an additional spin with Ising coupling, contrasting previous mathematical approaches.

Findings

Parity symmetry is broken by bias and restored by adding an extra spin.

The proposed model is experimentally feasible.

The method provides a new way to control symmetry in quantum systems.

Abstract

We explore the possibility to generate new parity symmetry in the quantum Rabi model after a bias is introduced. In contrast to a mathematical treatment in a previous publication [J. Phys. A 46, 265302 (2013)], we consider a physically realistic method by involving an additional spin into the quantum Rabi model to couple with the original spin by an Ising interaction. The rule can be found that the parity symmetry is broken by introducing a bias and then restored by adding new degrees of freedom. Experimental feasibility of realizing the models under discussion is investigated.