Condensed phase of Bose-Fermi mixtures with a pairing interaction

TL;DR

This paper investigates the condensed phase of Bose-Fermi mixtures with tunable pairing interactions, revealing universal behaviors and connecting condensate fraction to Fermi polaron properties through advanced many-body and quantum Monte Carlo methods.

Contribution

It introduces a comprehensive analysis of Bose-Fermi mixtures, demonstrating universal behavior and linking condensate fraction to Fermi polaron quasiparticle weight.

Findings

Universal behavior of condensate fraction and momentum distribution

Condensate fraction reduces to Fermi polaron quasiparticle weight at low boson density

Application of many-body diagrammatic methods and Quantum Monte Carlo simulations

Abstract

We study the condensed phase of a Bose-Fermi mixture with a tunable pairing interaction between bosons and fermions with many-body diagrammatic methods and fixed-node diffusion Quantum Monte Carlo simulations. A universal behavior of the condensate fraction and bosonic momentum distribution with respect to the boson concentration is found to hold in an extended range of boson-fermion couplings and concentrations. For vanishing boson density, we prove that the bosonic condensate fraction reduces to the quasiparticle weight Z of the Fermi polaron studied in the context of polarized Fermi gases, unifying in this way two apparently unrelated quantities.