Feshbach resonances in an ultracold $^7$Li and $^{87}$Rb mixture

TL;DR

This paper reports the observation of five Feshbach resonances in an ultracold mixture of $^7$Li and $^{87}$Rb, providing data crucial for tuning interspecies interactions and refining potential models.

Contribution

It presents the experimental detection of Feshbach resonances in a $^7$Li-$^{87}$Rb mixture and refines interaction potentials using coupled channels calculations.

Findings

Five Feshbach resonances observed in the mixture.

Identification of a broad resonance around 649 G.

Refined interspecies interaction potential parameters.

Abstract

We report on the observation of five Feshbach resonances in collisions between ultracold $^7$Li and $^{87}$Rb atoms in the absolute ground state mixture where both species are in their $|f,m_f>=|1,1>$ hyperfine states. The resonances appear as trap losses for the $^7$Li cloud induced by inelastic heteronuclear three-body collisions. The magnetic field values where they occur are important quantities for an accurate determination of the interspecies interaction potentials. Results of coupled channels calculations based on the observed resonances are presented and refined potential parameters are given. A very broad Feshbach resonance centered around 649 G should allow for fine tuning of the interaction strength in future experiments.