Feshbach spectroscopy and scattering properties of ultracold Li+Na mixtures

TL;DR

This study identifies and characterizes 26 Feshbach resonances in ultracold Li+Na mixtures, providing detailed interaction models and predicting tunable resonances for future experiments.

Contribution

The paper reports the first observation of multiple Feshbach resonances in Li+Na mixtures and refines interaction potentials for accurate resonance prediction.

Findings

26 interspecies Feshbach resonances observed

Most resonances have d-wave character

Improved interaction potentials match experimental data

Abstract

We have observed 26 interspecies Feshbach resonances at fields up to 2050 G in ultracold $^6$Li+$^{23}$Na mixtures for different spin-state combinations. Applying the asymptotic bound-state model to assign the resonances, we have found that most resonances have d-wave character. This analysis serves as guidance for a coupled-channel calculation, which uses modified interaction potentials to describe the positions of the Feshbach resonances well within the experimental uncertainty and to calculate their widths. The scattering length derived from the improved interaction potentials is experimentally confirmed and deviates from previously reported values in sign and magnitude. We give prospects for $^7$Li+$^{23}$Na and predict broad Feshbach resonances suitable for tuning.