Formation of Quantum-Degenerate Sodium Molecules

Abstract

Ultracold 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.