Three-body recombination of two-component cold atomic gases into deep dimers in an optical model

TL;DR

This paper models three-body recombination into deep dimers in two-component cold atomic gases using an optical potential approach, analyzing effects of scattering lengths, masses, and temperature on Efimov features and recombination rates.

Contribution

It introduces an optical model with an imaginary potential to study deep dimer recombination, providing detailed analysis of Efimov peaks and universal optical parameters.

Findings

Recombination peaks depend on scattering lengths and masses.

Temperature smearing reduces higher Efimov peaks.

Model predictions agree well with experimental data.

Abstract

We consider three-body recombination into deep dimers in a mass-imbalanced two-component atomic gas. We use an optical model where a phenomenological imaginary potential is added to the lowest adiabatic hyper-spherical potential. The consequent imaginary part of the energy eigenvalue corresponds to the decay rate or recombination probability of the three-body system. The method is formulated in details and the relevant qualitative features are discussed as functions of scattering lengths and masses. We use zero-range model in analyses of recent recombination data. The dominating scattering length is usually related to the non-equal two-body systems. We account for temperature smearing which tends to wipe out the higher-lying Efimov peaks. The range and the strength of the imaginary potential determine positions and shapes of the Efimov peaks as well as the absolute value of the recombination rate. The Efimov scaling between recombination peaks is calculated and shown to depend on both scattering lengths. Recombination is predicted to be largest for heavy-heavy-light systems. Universal properties of the optical parameters are indicated. We compare to available experiments and find in general very satisfactory agreement.