Effect of interactions on harmonically confined Bose-Fermi mixtures in optical lattices

TL;DR

This paper studies how interactions affect a Bose-Fermi mixture in a 3D optical lattice with harmonic trapping, revealing a condensate peak near zero interspecies interaction due to particle redistribution and phase space effects.

Contribution

It demonstrates the impact of interactions on condensate behavior in Bose-Fermi mixtures using a non-perturbative dynamical mean-field approach within a single-band model.

Findings

Condensate fraction peaks near zero Bose-Fermi interaction.

Interaction-induced particle redistribution influences condensate properties.

Reduced phase space at strong interactions increases temperature at fixed entropy.

Abstract

We investigate a Bose-Fermi mixture in a three-dimensional optical lattice, trapped in a harmonic potential. Using Generalized Dynamical Mean-Field theory, which treats the Bose-Bose and Bose-Fermi interaction in a fully non-perturbative way, we show that for experimentally relevant parameters a peak in the condensate fraction close to the point of vanishing Bose-Fermi interaction is reproduced within a single band framework. We identify two physical mechanisms contributing to this effect: the spatial redistribution of particles when the interspecies interaction is changed and the reduced phase space for strong interactions, which results in a higher temperature at fixed entropy.