Mott insulators and correlated superfluids in ultracold Bose-Fermi mixtures

TL;DR

This paper investigates how interactions in ultracold Bose-Fermi mixtures in optical lattices can destroy the Mott insulator phase, leading to a correlated superfluid phase with unique order properties.

Contribution

It introduces a detailed analysis of the transition from Mott insulator to superfluid in Bose-Fermi mixtures, highlighting the coexistence of superfluid and pseudo-spin density wave correlations.

Findings

Destruction of the Mott phase by boson-fermion interactions

Emergence of a correlated superfluid phase

Presence of combined superfluid and pseudo-spin density wave order

Abstract

We study the effects of interaction between bosons and fermions in a Bose-Fermi mixtures loaded in an optical lattice. We concentrate on the destruction of a bosonic Mott phase driven by repulsive interaction between bosons and fermions. Once the Mott phase is destroyed, the system enters a superfluid phase where the movements of bosons and fermions are correlated. We show that this phase has simultaneously correlations reminiscent of a conventional superfluid and of a pseudo-spin density wave order.