Spin-selective insulators in Bose-Fermi mixtures

TL;DR

This paper explores novel spin-selective insulating phases in Bose-Fermi mixtures, revealing how interactions and imbalance lead to distinct insulating states with specific commensurability relations, which can be tested in cold-atom experiments.

Contribution

It identifies and characterizes new spin-selective insulators in Bose-Fermi mixtures, detailing their conditions and potential experimental realizations.

Findings

Three insulating phases identified: mixed Mott and two spin-selective insulators.

Distinct commensurability relations for repulsive and attractive interactions.

Potential for experimental verification in cold-atom setups.

Abstract

We investigate an imbalanced mixture composed of two-color fermions and scalar bosons in the hard-core limit, considering repulsive and attractive interspecies and intraspecies interactions. The interplay between commensurability, repulsive interactions and imbalance generates three insulating phases: a mixed Mott state and two spin-selective insulators characterized by the commensurability relations $\rho_B+\rho^{\uparrow,(\downarrow)}_F=1$. For an attractive coupling between fermions and bosons, we found the relations $\rho_B-\rho^{\uparrow,(\downarrow)}_F=0$ for the spin-selective insulators. State-of-the-art cold-atoms setups constitute ideal platforms to implement these unveiled insulating states and verify their commensurability relations.