Atom-molecule equilibration in a degenerate Fermi gas with resonant interactions

TL;DR

This paper develops a kinetic theory for atom-molecule dynamics in a resonantly interacting Fermi gas, explaining experimental saturation effects and enhanced conversion efficiency at low temperatures.

Contribution

It introduces a nonequilibrium kinetic model for atom-molecule populations in a Fermi gas with Feshbach resonance, focusing on the pseudogap regime.

Findings

Predicts saturation of molecule formation observed experimentally

Shows enhanced atom-molecule conversion efficiency at low temperatures

Provides a simple model for atom-molecule population dynamics

Abstract

We present a nonequilibrium kinetic theory describing atom-molecule population dynamics in a two-component Fermi gas with a Feshbach resonance. Key collision integrals emerge that govern the relaxation of the atom-molecule mixture to chemical and thermal equilibrium. Our focus is on the pseudogap regime where molecules form above the superfluid transition temperature. In this regime, we formulate a simple model for the atom-molecule population dynamics. The model predicts the saturation of molecule formation that has been observed in recent experiments, and indicates that a dramatic enhancement of the atom-molecule conversion efficiency occurs at low temperatures.