Feshbach resonance in dense ultracold Fermi gases

TL;DR

This paper presents a theoretical framework for understanding many-body effects in dense ultracold Fermi gases near Feshbach resonances, highlighting how Pauli exclusion modifies scattering properties and explains experimental observations.

Contribution

It introduces a coherent theoretical model that accounts for many-body effects and the energy dependence of scattering length in dense Fermi gases with Feshbach resonances.

Findings

Pauli exclusion significantly alters scattering properties

Feshbach resonance is smeared in dense gases

The model explains recent experimental results

Abstract

We propose a coherent framework allowing to deal with many-body effects in dense ultracold Fermi gases in the presence of a Feshbach resonance. We show that the simple effect of Pauli exclusion induces a strong modification of the basic scattering properties, leading in particular to an energy dependence of the effective scattering length on the scale of the chemical potential. This results in a smearing of the Feshbach resonance and provides a natural explanation for recent experimental findings.