Quantum phase transition of light in a finite size Dicke model with Kerr-type nonlinearity

Abstract

In this paper we investigate a ground state quantum phase transition of nonlinear light in a generalized finite size Dicke model, which includes a Kerr-type nonlinear field term along with the counter-rotating interaction. The numerical solution is presented. We show that, in the ground state, the intracavity photons exhibit a third-order QPT from the bunching to the antibunching quantum phase. This phase transition stems from the competition between the atom-induced coupling and the effective photon–photon interaction. We also demonstrate that the general properties of the phase transition do not qualitatively alter by the size of the atomic ensemble and by the detuning between atoms and light, as well.