Trapping cold ground state argon atoms for sympathetic cooling of molecules

TL;DR

This study demonstrates trapping of cold ground-state argon atoms using a build-up cavity, enabling sympathetic cooling of molecules, and introduces a novel detection method based on collisional loss spectroscopy.

Contribution

It presents a new technique for trapping and detecting ground-state argon atoms and measures their polarizability ratio and loss rates, advancing cold atom and molecule research.

Findings

Successfully trapped ground-state argon atoms in a deep optical dipole trap.

Developed a parametric loss spectroscopy method for indirect detection.

Measured the polarizability ratio and loss rates of metastable argon atoms.

Abstract

We trap cold, ground-state, argon atoms in a deep optical dipole trap produced by a build-up cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of co-trapped metastable argon atoms using a new type of parametric loss spectroscopy. Using this technique we also determine the polarizability ratio between the ground and the metastable 4s[3/2]$_2$ state to be 40$\pm6$ and find a polarisability of (7.3$\pm$1.1) $\times$10$^{-39}$ Cm$^2/$V for the metastable state. Finally, Penning and associative losses of metastable atoms, in the absence of light assisted collisions, are determined to be $(3.3\pm 0.8) \times 10^{-10}$ cm$^3$s$^{-1}$.