Soliton trains in Bose-Fermi mixtures

TL;DR

This paper theoretically explores how strong Bose-Fermi attraction can induce effective attraction in bosons, leading to the formation of bright soliton trains in Bose-Fermi mixtures.

Contribution

It demonstrates the possibility of creating bright solitons in Bose-Fermi mixtures by tuning interspecies interactions, a novel approach in ultracold atomic gases.

Findings

Bright soliton trains form after increasing Bose-Fermi attraction.

Effective attraction in bosons is induced by strong Bose-Fermi attraction.

Soliton trains can be generated via Feshbach resonance or radial squeezing.

Abstract

We theoretically consider the formation of bright solitons in a mixture of Bose and Fermi degenerate gases. While we assume the forces between atoms in a pure Bose component to be effectively repulsive, their character can be changed from repulsive to attractive in the presence of fermions provided the Bose and Fermi gases attract each other strongly enough. In such a regime the Bose component becomes a gas of effectively attractive atoms. Hence, generating bright solitons in the bosonic gas is possible. Indeed, after a sudden increase of the strength of attraction between bosons and fermions (realized by using a Feshbach resonance technique or by firm radial squeezing of both samples) soliton trains appear in the Bose-Fermi mixture.