Boson-fermion demixing in a cloud of lithium atoms in a pancake trap

TL;DR

This paper investigates the demixing behavior of a lithium atom mixture in a pancake-shaped trap, showing that trap squeezing alone can induce phase separation without changing scattering lengths.

Contribution

It demonstrates how trap geometry influences boson-fermion demixing, providing a method to observe phase separation without Feshbach resonance tuning.

Findings

Demixing can be achieved by squeezing the trap

Effective couplings depend on axial confinement

Full demixing observable without changing scattering lengths

Abstract

We evaluate the equilibrium state of a mixture of 7Li and 6Li atoms with repulsive interactions, confined inside a pancake-shaped trap under conditions such that the thickness of the bosonic and fermionic clouds is approaching the values of the s-wave scattering lengths. In this regime the effective couplings depend on the axial confinement and full demixing can become observable by merely squeezing the trap, without enhancing the scattering lengths through recourse to a Feshbach resonance.