Stability Condition of a Strongly Interacting Boson-Fermion Mixture across an Inter-Species Feshbach Resonance

TL;DR

This paper investigates the stability and properties of a dilute boson-fermion mixture across a Feshbach resonance, revealing universal stability conditions and analyzing quantum depletion, momentum distribution, and phase transitions.

Contribution

It provides a universal stability criterion dependent on the scattering length and explores the mixture's behavior across the resonance, including quantum depletion and phase transition insights.

Findings

Stability requires a minimum bare interaction exceeding a critical value.

The stability condition is a universal function of the boson-fermion scattering length.

Quantum depletion and momentum distribution are characterized across the resonance.

Abstract

We study the properties of dilute bosons immersed in a single component Fermi sea across a broad boson-fermion Feshbach resonance. The stability of the mixture requires that the bare interaction between bosons exceeds a critical value, which is a universal function of the boson-fermion scattering length, and exhibits a maximum in the unitary region. We calculate the quantum depletion, momentum distribution and the boson contact parameter across the resonance. The transition from condensate to molecular Fermi gas is also discussed.