Quantum Monte Carlo study of the indirect Pauli exclusion effect in Bose-Fermi mixtures

TL;DR

This paper investigates the indirect Pauli exclusion effect in a three-dimensional Bose-Fermi mixture at zero temperature, revealing how low-momentum depletion signals a quantum phase transition using Monte Carlo and T-matrix methods.

Contribution

It introduces the concept of the indirect Pauli exclusion effect in Bose-Fermi mixtures and demonstrates it through advanced quantum Monte Carlo simulations and T-matrix calculations.

Findings

Bosonic condensate fraction vanishes at the transition

Low-momentum depletion depends on boson concentration

The effect is demonstrated via Fixed-Node Diffusion Monte Carlo and T-matrix methods

Abstract

We study the momentum distributions of a three-dimensional resonant Bose-Fermi mixture in the molecular limit at zero temperature. For concentration of the bosons with respect to the fermions less or equal to one, each boson is bound to a fermion and the system is composed of fermionic molecules plus excess fermions. Not only the bosonic condensate fraction goes to zero, signaling a quantum phase transition towards a normal phase, but a finite region of low momenta is depleted, depending on the concentration. This phenomenon is named indirect Pauli exclusion effect and is demonstrated via Fixed-Node Diffusion Monte Carlo simulations and T-matrix calculations.