Nonequilibrium Phase Transition of Interacting Bosons in an Intra-Cavity Optical Lattice

TL;DR

This paper explores the nonequilibrium quantum phase transitions of interacting bosons in an optical lattice within a cavity, revealing transitions from normal to superfluid and Mott insulator phases driven by light-matter interactions.

Contribution

It introduces a generalized Bose-Hubbard model including cavity backaction and uses dynamical mean-field theory to analyze quantum phases in cavity QED systems.

Findings

Identifies a transition from normal to superfluid phase related to superradiance.

Discovers a self-organized Mott insulator phase at higher pump strengths.

Provides a theoretical framework matching recent experimental parameters.

Abstract

We investigate the nonlinear light-matter interaction of a Bose-Einstein condensate trapped in an external periodic potential inside an optical cavity which is weakly coupled to vacuum radiation modes and driven by a transverse pump field. Based on a generalized Bose-Hubbard model which incorporates a single cavity mode, we include the collective backaction of the atoms on the cavity light field and determine the nonequilibrium quantum phases within the nonperturbative bosonic dynamical mean-field theory.With the system parameters adapted to recent experiments, we find a quantum phase transition from a normal phase to a self-organized superfluid phase, which is related to the Hepp-Lieb-Dicke superradiance phase transition. For even stronger pumping, a self-organized Mott insulator phase arises.