Creating ultracold molecules by collisions with ultracold rare gas atoms in an optical trap

TL;DR

This study investigates the potential for cooling para-H₂ molecules to ultracold temperatures through collisions with various ultracold rare gas atoms in an optical trap, highlighting argon and helium as the most promising candidates.

Contribution

The paper provides a comprehensive analysis of collision cross-sections between para-H₂ and five rare gas atoms across a wide temperature range, assessing their suitability for sympathetic cooling.

Findings

All five rare gas species could cool H₂ to ultracold temperatures.

Argon and helium are identified as the most promising for future experiments.

Collision cross-sections remain significant over the entire temperature range.

Abstract

We study collisions of para-H$_2$ with five rare gas atomic species (He, Ne, Ar, Kr and Xe) over the range from 1 K to 1 $\mu$ K and evaluate the feasibility of sympathetic cooling H$_2$ with ultracold ground state rare gas atoms co-trapped within a deep optical trap. Collision cross-sections over this large temperature range show that all of these species could be used to cool H$_2$ to ultracold temperatures and that argon and helium are the most promising species for future experiments.