Triatomic Photoassociation in an Ultracold Atom-Molecule Collision

TL;DR

This paper presents a detailed theoretical study of triatomic photoassociation in ultracold atom-molecule collisions, calculating potential energy curves and PA rates, and validating the model against known experimental data.

Contribution

It introduces a comprehensive theoretical model for triatomic photoassociation in ultracold collisions, including long-range interactions and spin-orbit effects, with validation against experimental results.

Findings

Calculated potential energy curves for triatomic complexes.

Predicted PA rates for Na and Cs collisions.

Model shows good agreement with experimental Cs$_3$ formation rates.

Abstract

Ultracold collisions of neutral atoms and molecules have been of great interest since experimental advances enabled the cooling and trapping of such species. This study is a theoretical investigation of a low-energy collision between an alkali atom and a diatomic molecule, accompanied by absorption of a photon from an external electromagnetic field. The long-range interaction between the two species is treated, including the atomic spin-orbit interaction. The long-range potential energy curves for the triatomic complex are calculated in realistic detail, while the short-range behavior is mimicked by applying different boundary conditions at the van der Waals length. The photoassociation (PA) rate of an atom colliding with a dimer is calculated for different alkali atoms, namely Na and Cs. The model developed in this study is also tested against known results for the formation rate of the Cs$_3$ complex via PA, namely to compare with the work done by Rios et al., PRL 115, 073201 (2015), and the results are in generally good agreement.