Molecular superfluid phase in systems of one-dimensional multicomponent fermionic cold atoms

TL;DR

This paper investigates a one-dimensional model of multicomponent fermionic cold atoms, revealing a molecular superfluid phase characterized by bound states of N fermions, which emerges under attractive interactions at low density.

Contribution

The study combines analytical and numerical methods to identify a novel molecular superfluid phase in multicomponent fermionic systems with contact interactions.

Findings

Molecular superfluid phase appears at low density for attractive interactions.

Bound states of N fermions dominate the superfluid instability.

Phase exists without requiring SU(N) symmetry among hyperfine states.

Abstract

We study a simple model of N-component fermions with contact interactions which describes fermionic atoms with N=2F+1 hyperfine states loaded into a one-dimensional optical lattice. We show by means of analytical and numerical approaches that, for attractive interaction, a quasi-long-range molecular superfluid phase emerges at low density. In such a phase, the pairing instability is strongly suppressed and the leading instability is formed from bound-states made of N fermions. At small density, the molecular superfluid phase is generic and exists for a wide range of attractive contact interactions without an SU(N) symmetry between the hyperfine states.