Building one molecule from a reservoir of two atoms

TL;DR

This paper demonstrates a novel method for precisely combining two laser-cooled atoms into a single molecule using optical traps, enabling detailed study and potential synthesis of complex molecules in a controlled environment.

Contribution

It introduces a new experimental technique for merging two individual atoms into a molecule, advancing control over chemical reactions at the quantum level.

Findings

Discovery of new resonances near the dissociation threshold

Measurement of atomic collision rates in ultracold conditions

Potential for synthesizing designer molecules for quantum computing

Abstract

Chemical reactions typically proceed via stochastic encounters between reactants. Going beyond this paradigm, we combine exactly two atoms into a single, controlled reaction. The experimental apparatus traps two individual laser-cooled atoms (one sodium and one cesium) in separate optical tweezers and then merges them into one optical dipole trap. Subsequently, photoassociation forms an excited-state NaCs molecule. The discovery of previously unseen resonances near the molecular dissociation threshold and measurement of collision rates are enabled by the tightly trapped ultracold sample of atoms. As laser-cooling and trapping capabilities are extended to more elements, the technique will enable the study of more diverse, and eventually more complex, molecules in an isolated environment, as well as synthesis of designer molecules for qubits.