A Finite Temperature Treatment of Ultracold Atoms in a 1-D Optical Lattice

TL;DR

This paper investigates how finite temperature affects the superfluid phase of ultracold bosons in a 1-D optical lattice using a Hartree-Fock-Bogoliubov approach, revealing an increased critical temperature for Bose condensation.

Contribution

It introduces a finite temperature analysis of the Bose-Hubbard model for 1-D optical lattices, including harmonic confinement, highlighting shifts in critical temperature.

Findings

Critical temperature for Bose condensation increases with temperature.

Harmonic confinement alters the behavior compared to uniform gases.

Finite temperature effects are significant in 1-D optical lattice systems.

Abstract

We consider the effects of temperature upon the superfluid phase of ultracold, weakly interacting bosons in a one dimensional optical lattice. We use a finite temperature treatment of the Bose-Hubbard model based upon the Hartree-Fock-Bogoliubov formalism, considering both a translationally invariant lattice and one with additional harmonic confinement. In both cases we observe an upward shift in the critical temperature for Bose condensation. For the case with additional harmonic confinement, this is in contrast with results for the uniform gas.