Probing the critical point of the Jaynes-Cummings second-order dissipative quantum phase transition

TL;DR

This paper investigates the quantum fluctuations involved in a dissipative quantum phase transition within the driven Jaynes-Cummings model, revealing significant deviations from semiclassical predictions and highlighting quantum bistability phenomena.

Contribution

It provides a detailed quantum analysis of the phase transition, emphasizing the role of quantum fluctuations and bistability, which were not captured by previous semiclassical approaches.

Findings

Quantum fluctuations significantly influence the phase transition.

Quantum bistability and spontaneous dressed-state polarization are observed.

Quantum states coexist as predicted by neoclassical theory.

Abstract

We highlight the importance of quantum fluctuations in organizing a dissipative quantum phase transition for the driven Jaynes-Cummings interaction with variable qubit-cavity detuning. The system response presents a substantial difference from the predictions of the semiclassical theory, the extent of which is revealed in the properties of quantum bistability, and visualized with the help of quasi-distribution functions for the cavity field, subject to an appropriate scale parameter. States anticipated by the neoclassical theory of radiation coexist in the quantum picture, following the occurrence of spontaneous dressed-state polarization and phase bistability at resonance.