Quantum phase transition of light in the dissipative Rabi-Hubbard lattice: A dressed-master-equation perspective

TL;DR

This paper analyzes the quantum phase transition of light in a dissipative Rabi-Hubbard lattice using a dressed master equation, revealing zero critical tunneling at zero temperature in the deep-strong coupling regime, contrasting previous models.

Contribution

It introduces a dressed master equation approach to study photon phase transitions, showing new critical behavior differing from standard Lindblad models.

Findings

Critical tunneling approaches zero at zero temperature in deep-strong coupling.

Significant improvement in critical tunneling at finite temperature.

Contrasts with previous Lindblad-based results.

Abstract

In this work, we investigate the quantum phase transition of light in the dissipative Rabi-Hubbard lattice under the framework of the mean-field theory and quantum dressed master equation. The order parameter of photons in strong qubit-photon coupling regime is derived analytically both at zero and low temperatures. Interestingly, we can locate the localization and delocalization phase transition very well in a wide parameter region. {In particular for the zero-temperature limit, the critical tunneling strength approaches zero generally in the deep-strong qubit-photon coupling regime, regardless of the quantum dissipation. This is contrary to the previous results with the finite minimal critical tunneling strength based on the standard Lindblad master equation. Moreover, a significant improvement of the critical tunneling is also observed at finite temperature, compared with the counterpart under the Lindblad description. We hope these results may deepen the understanding of the phase transition of photons in the Rabi-Hubbard model.