Commensurate mixtures of ultra-cold atoms in one dimension

TL;DR

This paper investigates the phase behavior of one-dimensional ultra-cold atom mixtures in optical lattices, deriving phase diagrams and identifying various ordered phases using a Luttinger liquid framework and renormalization group analysis.

Contribution

It introduces a comprehensive RG analysis for commensurate ultra-cold atom mixtures, revealing complex phase diagrams and multiple ordered phases.

Findings

Identification of charge/spin density wave phases

Discovery of singlet and triplet pairing regimes

Prediction of a supersolid phase in the mixtures

Abstract

We study binary mixtures of ultra-cold atoms, confined to one dimension in an optical lattice, with commensurate densities. Within a Luttinger liquid description, which treats various mixtures on equal footing, we derive a system of renormalization group equations at second order, from which we determine the rich phase diagrams of these mixtures. These phases include charge/spin density wave order, singlet and triplet pairing, polaron pairing, and a supersolid phase. Various methods to detect our results experimentally are discussed.