Formation of Quantum-Degenerate Sodium Molecules

TL;DR

This paper reports the creation of quantum-degenerate sodium molecules from a Bose-Einstein condensate using Feshbach resonance, achieving high phase-space density and efficient molecule formation.

Contribution

It demonstrates a method to produce ultra-cold sodium molecules with high phase-space density from a BEC, including techniques to remove residual atoms and analyze molecular properties.

Findings

Over 10^5 molecules generated

Conversion efficiency of approximately 4%

Phase-space density greater than 20

Abstract

Ultra-cold sodium molecules were produced from an atomic Bose-Einstein condensate by ramping an applied magnetic field across a Feshbach resonance. More than $10^5$ molecules were generated with a conversion efficiency of $\sim$4%. Using laser light resonant with an atomic transition, the remaining atoms could be selectively removed, preventing fast collisional relaxation of the molecules. Time-of-flight analysis of the pure molecular sample yielded an instantaneous phase-space density greater than 20.