Heteronuclear molecules in an optical dipole trap

TL;DR

This paper reports the creation and detailed characterization of heteronuclear KRb Feshbach molecules in an optical dipole trap, including efficiency, temperature dependence, and binding energy measurements, advancing ultracold molecule research.

Contribution

It demonstrates the successful formation of heteronuclear molecules with high efficiency and provides new measurements of their binding energies near Feshbach resonances.

Findings

Created up to 25,000 molecules at 300 nK

Achieved 25% conversion efficiency

Measured binding energies up to 26 MHz

Abstract

We report on the creation and characterization of heteronuclear KRb Feshbach molecules in an optical dipole trap. Starting from an ultracold gas mixture of K-40 and Rb-87 atoms, we create as many as 25,000 molecules at 300 nK by rf association. Optimizing the association process, we achieve a conversion efficiency of 25%. We measure the temperature dependence of the rf association process and find good agreement with a phenomenological model that has previously been applied to Feshbach molecule creation by slow magnetic-field sweeps. We also present a measurement of the binding energy of the heteronuclear molecules in the vicinity of the Feshbach resonance and provide evidence for Feshbach molecules as deeply bound as 26 MHz.