Superfluid and Mott Insulator phases of one-dimensional Bose-Fermi mixtures

TL;DR

This paper investigates the phase diagram of one-dimensional Bose-Fermi mixtures in optical lattices, revealing various superfluid and Mott insulator phases through quantum Monte Carlo simulations, and analyzing correlations between species.

Contribution

It provides comprehensive phase diagrams for Bose-Fermi mixtures in 1D optical lattices, highlighting the interplay of interactions and fillings on phase behavior.

Findings

Identification of superfluid and Mott insulator phases

Correlation effects between bosons and fermions

Complete phase diagrams at various fillings and interactions

Abstract

We study the ground state phases of Bose-Fermi mixtures in one-dimensional optical lattices with quantum Monte Carlo simulations using the Canonical Worm algorithm. Depending on the filling of bosons and fermions, and the on-site intra- and inter-species interaction, different kinds of incompressible and superfluid phases appear. On the compressible side, correlations between bosons and fermions can lead to a distinctive behavior of the bosonic superfluid density and the fermionic stiffness, as well as of the equal-time Green functions, which allow one to identify regions where the two species exhibit anticorrelated flow. We present here complete phase diagrams for these systems at different fillings and as a function of the interaction parameters.