Efimov Physics in Atom-Dimer Scattering of Lithium-6 Atoms

TL;DR

This paper uses universal effective field theory to analyze Efimov physics in lithium-6 atom-dimer scattering, explaining experimental features and emphasizing the importance of finite temperature effects.

Contribution

It provides a theoretical calculation of atom-dimer relaxation rates that qualitatively matches experimental observations and highlights the significance of finite temperature corrections.

Findings

Four features in relaxation rate are qualitatively explained

Finite temperature effects improve theory-experiment agreement

Implied existence of a hidden local minimum

Abstract

Lithium-6 atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective field theory to calculate the atom-dimer relaxation rate at zero temperature. Our results describe the four features qualitatively and imply there is a hidden local minimum. In the vicinity of the resonance at 685 G, we perform a finite temperature calculation which improves the agreement of theory and experiment. We conclude that finite temperature effects cannot be neglected in the analysis of the experimental data.