Stability and pairing in quasi-one-dimensional Bose-Fermi mixtures

TL;DR

This paper investigates a coupled-tube system of Bose-Fermi mixtures, revealing phase separation with attractive interactions and the suppression of instabilities at high inter-tube hopping, paving the way for novel paired superfluid phases.

Contribution

It demonstrates the suppression of phase separation and instabilities in coupled-tube Bose-Fermi mixtures, highlighting the potential for realizing exotic paired superfluid phases.

Findings

Phase separation occurs with attractive interactions.

High inter-tube hopping suppresses first-order instabilities.

Potential for p-wave superfluidity and quantum critical phenomena.

Abstract

We consider a mixture of single-component bosonic and fermionic atoms in an array of coupled one-dimensional "tubes". For an attractive Bose-Fermi interaction, we show that the system exhibits phase separation instead of the usual collapse. Moreover, above a critical inter-tube hopping, all first-order instabilities disappear in both attractive and repulsive mixtures. The possibility of suppressing instabilities in this system suggests a route towards the realization of paired phases, including a superfluid of p-wave pairs unique to the coupled-tube system, and quantum critical phenomena.