Interacting bosons in an optical lattice: Bose-Einstein condensates and Mott insulator

TL;DR

This paper explores the phase diagram of interacting bosons in an optical lattice, analyzing Bose-Einstein condensates and Mott insulators through a mean-field approach at various temperatures.

Contribution

It introduces a mean-field theory that describes both condensate and Mott insulator phases, including finite temperature effects and detailed physical properties.

Findings

Calculated densities and excitation spectra for both phases

Identified phase boundaries between condensate and Mott insulator

Analyzed static structure factors across phases

Abstract

A dense Bose gas with hard-core interaction is considered in an optical lattice. We study the phase diagram in terms of a special mean-field theory that describes a Bose-Einstein condensate and a Mott insulator with a single particle per lattice site for zero as well as for non-zero temperatures. We calculate the densities, the excitation spectrum and the static structure factor for each of these phases.