BCS-BEC crossover of the strongly interacting $^6$Li-$^{40}$K mixture

TL;DR

This paper uses Quantum Monte Carlo methods to study the BCS-BEC crossover in a strongly interacting, mass-imbalanced $^6$Li-$^{40}$K Fermi gas, providing detailed predictions of its equation of state, structure, and quasiparticle spectrum.

Contribution

It offers the first comprehensive Quantum Monte Carlo analysis of the $^6$Li-$^{40}$K mixture across the BCS-BEC crossover, including effects of mass imbalance and interaction range.

Findings

Equation of state at unitarity calculated

Pair and momentum distribution functions characterized

Heavy/light quasiparticle spectrum computed

Abstract

We present Quantum Monte Carlo calculations of the properties of a two-component mass imbalanced Fermi gas, corresponding to the $^6$Li-$^{40}$K mixture. We compute the equation of state of the unpolarized system as a function of the scattering length with particular attention paid to the unitary limit, where the effect of the effective range of the interaction is explored. We have also computed the pair distribution function and the momentum distribution over a range of interaction strengths to provide information about the structure of the system. Finally, we have computed the heavy/light quasiparticle spectrum. Our theoretical predictions, based on Quantum Monte Carlo calculations, can be tested by future experiments with ultracold fermionic gases.