Ground-state properties of a dilute Bose-Fermi mixture

TL;DR

This paper studies the ground-state properties of a dilute Bose-Fermi mixture at zero temperature, focusing on how interspecies interactions influence various physical characteristics using Green's function formalism.

Contribution

It provides a second-order calculation of the ground-state energy and analyzes the effects of Bose-Fermi interactions on excitations and condensate properties.

Findings

Bose-Fermi interactions modify phonon spectra.

Interactions affect condensate fraction and superfluid density.

Quantitative results for attractive interspecies interactions.

Abstract

We investigate the properties of a dilute boson-fermion mixture at zero temperature. The ground-state energy of the system is calculated to second order in the Bose-Fermi coupling constant. The Green's function formalism is applied to obtain results for the effect of Bose-Fermi interactions on the spectrum of phonon excitations, the momentum distribution, the condensate fraction and the superfluid density of the bosonic component. A quantitative discussion of these effects is presented in the case of mixtures with attractive interspecies interaction.