Two-component Bose-Hubbard model in an array of cavity polaritons

TL;DR

This paper proposes a scheme to realize a two-component Bose-Hubbard model with polaritons in optical cavities, analyzing phase transitions influenced by nonlinear interactions through mean-field, perturbation, and exact diagonalization methods.

Contribution

It introduces a novel realization scheme for an extended two-component Bose-Hubbard model with nonlinear couplings in cavity polaritons.

Findings

Phase diagram showing Mott insulator to superfluid transition

Nonlinear coupling terms significantly affect phase boundaries

Mean-field, perturbation, and exact diagonalization methods provide consistent insights

Abstract

We propose a scheme which can realize an extended two-component Bose-Hubbard model using polaritons confined in an array of optical cavities. In addition to the density-dependent interactions, this model also contains nonlinear coupling terms between the two components of the polariton. Using a mean-field calculation, we obtain the phase diagram which shows how these terms affect the transition between the Mott insulator and the superfluid phase. In addition, we employ both a perturbation approach and an exact diagonalization method to gain more insights into the phase diagram.