Robust finite-temperature disordered Mott insulating phases in inhomogeneous Fermi-Fermi mixtures with density and mass imbalance

TL;DR

This paper demonstrates the existence of a disordered Mott insulator phase in ultracold Fermi-Fermi mixtures with mass and density imbalance, using strong-coupling and Monte Carlo methods, relevant for experimental realization.

Contribution

It introduces the concept of a disordered Mott insulator phase in inhomogeneous Fermi-Fermi mixtures with mass and density imbalance, supported by computational analysis.

Findings

Disordered Mott insulator phase exists over a broad parameter range.

Phase characterized by incompressible total density but compressible relative density.

Phase is realizable with current experimental setups.

Abstract

Ultracold mixtures of different atomic species have great promise for realizing novel many-body phenomena. In a binary mixture of femions with a large mass difference and repulsive interspecies interactions, a disordered Mott insulator phase can occur. This phase displays an incompressible total density, although the relative density remain compressible. We use strong-coupling and Monte Carlo calculations to show that this phase exists for a broad parameter region for ultracold gases confined in a harmonic trap on a three-dimensional optical lattice, for experimentally accessible values of the trap parameters.