Collisions in a dual-species magneto-optical trap of molecules and atoms

TL;DR

This study investigates inelastic collisions between CaF molecules and $^{87}$Rb atoms in a dual-species magneto-optical trap, quantifying loss rates and analyzing collision mechanisms at millikelvin temperatures.

Contribution

It provides the first measurement of collisional loss rates between CaF molecules and rubidium atoms in a dual-species MOT, highlighting the role of rotation-changing collisions.

Findings

Loss rate coefficient measured as (1.43 ± 0.29) × 10^{-10} cm^3/s

Loss rates are unaffected by light-induced collisions or population variations

Observed loss rate aligns with the universal loss rate model

Abstract

We study inelastic collisions between CaF molecules and $^{87}$Rb atoms in a dual-species magneto-optical trap. The presence of atoms increases the loss rate of molecules from the trap. By measuring the loss rates and density distributions, we determine a collisional loss rate coefficient $k_{2} = (1.43 \pm 0.29) \times 10^{-10}$ cm$^{3}$/s at a temperature of 2.4 mK. We show that this is not substantially changed by light-induced collisions or by varying the populations of excited-state atoms and molecules. The observed loss rate is close to the universal rate expected in the presence of fast loss at short range, and can be explained by rotation-changing collisions in the ground electronic state.