Effective-Range Dependence of Resonantly Interacting Fermions

TL;DR

This paper investigates how the effective range influences the properties of resonantly interacting fermions, using quantum Monte Carlo and density functional theory to analyze universality and compare with experimental data.

Contribution

It provides the first ab initio calculations of effective-range corrections to the unitary Fermi gas equation of state, demonstrating their universality and consistency with existing results.

Findings

Effective-range corrections are universal across different two-body interactions.

Density functional theory aligns with quantum Monte Carlo and experimental data.

First QMC results with correct asymptotic scaling for trapped systems.

Abstract

We extract the leading effective range corrections to the equation of state of the unitary Fermi gas from ab initio fixed-node quantum Monte Carlo (FNQMC) calculations in a periodic box using a density functional theory (DFT), and show them to be universal by considering several two-body interactions. Furthermore, we find that the DFT is consistent with the best available unbiased QMC calculations, analytic results, and experimental measurements of the equation of state. We also discuss the asymptotic effective-range corrections for trapped systems and present the first QMC results with the correct asymptotic scaling.