Single-Photon-Triggered Quantum Phase Transition

TL;DR

This paper introduces a hybrid quantum model that demonstrates a single-photon-triggered quantum phase transition, immune to the no-go theorem, and explores photon-dependent quantum criticality and control of phase transitions.

Contribution

It presents a novel hybrid quantum model enabling single-photon-triggered QPT, including effects of the $A^2$ term, and reveals reversed superradiant QPT due to competing interactions.

Findings

Single-photon-triggered superradiant QPT demonstrated.

QPT occurs both with and without the $A^2$ term, defying the no-go theorem.

Reversed superradiant QPT induced by competition between $A^2$ term and optomechanics.

Abstract

We propose a hybrid quantum model combining cavity QED and optomechanics, which allows the occurrence of equilibrium superradiant quantum phase transition (QPT) triggered by a single photon. This single-photon-triggered QPT exists both in the cases of ignoring and including the so-called $A^2$ term, i.e., it is immune to the no-go theorem. It originally comes from the photon-dependent quantum criticality featured by the proposed hybrid quantum model. Moreover, a reversed superradiant QPT is induced by the competition between the introduced $A^2$ term and the optomechanical interaction. This work offers an approach to manipulate QPT with a single photon, which should inspire the exploration of single-photon quantum-criticality physics and the engineering of new single-photon quantum devices.