Dynamics of translational and rotational thermalization of AlF molecules via collisions with cryogenic helium

TL;DR

This study uses ab initio calculations and quantum scattering theory to analyze how helium cools AlF molecules' translational and rotational motions at cryogenic temperatures, confirming helium's effectiveness as a coolant.

Contribution

It introduces a new ab initio potential energy surface and applies quantum multichannel scattering to detail AlF helium collisions at cryogenic temperatures.

Findings

Helium efficiently cools AlF translationally and rotationally at millikelvin to kelvin temperatures.

The cooling efficiency remains robust despite potential PES inaccuracies.

Helium acts as an effective quencher for AlF in buffer gas cooling experiments.

Abstract

We investigated helium-mediated translational and rotational thermalization of the aluminum monofluoride (AlF) molecule at cryogenic temperatures via a new $ab \ initio$ potential energy surface (PES) and quantum multichannel scattering theory. Our examination of the elastic and rotationally inelastic channels revealed that helium is an efficient quencher of AlF at temperatures relevant to buffer gas cooling experiments ($\sim1$ mK to $10$ K). We also showed that this conclusion is robust against possible inaccuracies of the PES.