Electric field dependence of complex-dominated ultracold molecular collisions

TL;DR

This paper investigates how electric fields influence ultracold molecular collisions, explaining observed loss behaviors through a model that considers state mixing and density-of-states effects, with implications for controlling molecular interactions.

Contribution

The paper introduces a simple model linking electric field effects to collision loss probabilities, advancing understanding of ultracold molecular collision dynamics.

Findings

Loss probability near unity in electric fields

Loss probability non-universal without electric field

Model explains experimental observations

Abstract

Recent experiments on ultracold non-reactive dipolar molecules have observed high two-body losses, even though these molecules can undergo neither inelastic, nor reactive (as they are in their absolute ground state), nor light-assisted collisions (if they are measured in the dark). In the presence of an electric field these losses seem to be near universal (the probability of loss at short-range is near unity) while in the absence of it the losses seem non-universal. To explain these observations we propose a simple model based on the mixing effect of an electric field on the states of the two diatomic molecules at long-range and on the density-of-states of the tetramer complex formed at short-range, believed to be responsible for the losses. We apply our model to collisions of ground-state molecules of endothermic systems, of current experimental interest.