Quantum phases of a Feshbach-resonant atomic Bose gas in one dimension

TL;DR

This paper investigates the quantum phases of a one-dimensional atomic Bose gas with Feshbach resonance, revealing superfluid, Luttinger liquid, and charge density wave phases influenced by density commensurability.

Contribution

It characterizes the phase diagram of a 1D Bose gas with Feshbach resonance, identifying new phases and the effects of density commensurability on quantum states.

Findings

Superfluid phase dominates most parameter regions.

Two additional phases appear at commensurate density differences.

Identification of Luttinger liquid and charge density wave phases.

Abstract

We study an atomic Bose gas with an s-wave Feshbach resonance in a one-dimensional optical lattice, with the densities of atoms and molecules incommensurate with the lattice. At zero temperature, most of the parameter region is occupied by a phase in which the superfluid fluctuations of atoms and molecules are the predominant ones, due to the phase fluctuations of atoms and molecules being locked by a Josephson coupling between them. When the density difference between atoms and molecules is commensurate with the lattice, two additional phases may exist: the two component Luttinger liquid where both the atomic and molecular sectors are gapless, and the inter-channel charge density wave where the relative density fluctuations between atoms and molecules are frozen at low energy.