Efficient formation of deeply bound ultracold molecules probed by broadband detection

TL;DR

This paper reports an efficient broadband detection method revealing a high-yield formation process of deeply bound ultracold Cs$_2$ molecules via photoassociation and spontaneous emission, with potential applications to other molecules.

Contribution

The study introduces a broadband detection scheme that significantly improves the observation of deeply bound ultracold molecules formed through a one-photon photoassociation process.

Findings

Formed 10^5-10^6 molecules per second in low vibrational levels.

Discovered an efficient formation mechanism involving spontaneous emission cascades.

Demonstrated potential generalization to other molecular species.

Abstract

Using a non-selective broadband detection scheme we discovered an efficient mechanism of formation of ultracold Cs$_2$ molecules in deeply bound levels ($v=1-9$) of their electronic ground state X$^1 \Sigma_g^+$. They are formed by a one-photon photoassociation of ultracold cesium atoms in a manifold of excited electronic states, followed by a two-step spontaneous emission cascade. We were able to form about $10^5-10^6$ molecules per second in these low vibrational levels of the ground state. This detection scheme could be generalized to other molecular species for the systematic investigation of cold molecule formation mechanisms.