Ultracold mixtures of atomic Li-6 and Cs-133 with tunable interactions

TL;DR

This study explores tunable interactions in a cold atomic mixture of lithium-6 and cesium-133, identifying Feshbach resonances useful for molecule formation and few-body physics.

Contribution

It reports the first experimental observation and theoretical characterization of multiple s-wave Feshbach resonances in a Li-6 and Cs-133 mixture.

Findings

Identified five s-wave interspecies Feshbach resonances.

Two resonances are as wide as 60 G, suitable for molecule creation.

Constructed a coupled channels model fitting the observed resonances.

Abstract

We report the experimental and theoretical study of two-body interactions in a $^{6}$Li-$^{133}$Cs Fermi- Bose mixture. Using a translatable dipole trap setup, we have successfully trapped the two species in the same trap with temperatures of a few microkelvins. By monitoring atom number loss and inter-species thermalization, we identify five s-wave interspecies Feshbach resonances in the lowest two scattering channels. We construct a coupled channels model using molecular potentials to fit and characterize these resonances. Two of the resonances are as wide as 60 G and thus should be suitable for creating Feshbach molecules and searching for universal few-body scaling.