Boson-fermion mixtures inside an elongated cigar-shaped trap

TL;DR

This paper uses mean-field calculations to study the equilibrium states of boson-fermion mixtures in elongated traps, revealing conditions for demixing and collapse suppression, with specific focus on 7Li-6Li systems.

Contribution

It provides a detailed analysis of boson-fermion mixtures in elongated traps, highlighting the effects of interspecies interactions and particle numbers on stability and phase separation.

Findings

Demixing occurs only below a fermion number threshold with repulsive interactions.

Collapse is suppressed within the mean-field approximation for attractive interactions.

Numerical results are provided for 7Li-6Li atomic mixtures.

Abstract

We present mean-field calculations of the equilibrium state in a gaseous mixture of bosonic and spin-polarized fermionic atoms with repulsive or attractive interspecies interactions, confined inside a cigar-shaped trap under conditions such that the radial thickness of the two atomic clouds is approaching the magnitude of the s-wave scattering lengths. In this regime the kinetic pressure of the fermionic component is dominant. Full demixing under repulsive boson-fermion interactions can occur only when the number of fermions in the trap is below a threshold, and collapse under attractive interactions is suppressed within the range of validity of the mean-field model. Specific numerical illustrations are given for values of system parameters obtaining in 7Li-6Li clouds.