Study of Efimov physics in two nuclear-spin sublevels of 7Li

TL;DR

This study investigates Efimov physics in two nuclear-spin sublevels of bosonic lithium-7, revealing nuclear-spin independence of Efimov features and universal relations across Feshbach resonances, supported by precise resonance mapping.

Contribution

The paper provides the first detailed comparison of Efimov features in different nuclear-spin states of lithium-7, demonstrating their nuclear-spin independence and universal behavior across Feshbach resonances.

Findings

Efimov features are identical in both nuclear-spin sublevels within experimental errors.

Efimov features are universally related across different Feshbach resonances.

Precise determination of Feshbach resonance positions and scattering lengths through coupled channels calculations.

Abstract

Efimov physics in two nuclear-spin sublevels of bosonic lithium is studied and it is shown that the positions and widths of recombination minima and Efimov resonances are identical for both states within the experimental errors which indicates that the short-range physics is nuclear-spin independent. We also find that the Efimov features are universally related across Feshbach resonances. These results crucially depend on careful mapping between the scattering length and the applied magnetic field which we achieve by characterization of the two broad Feshbach resonances in the different states by means of rf-spectroscopy of weakly bound molecules. By fitting the binding energies numerically with a coupled channels calculation we precisely determine the absolute positions of the Feshbach resonances and the values of the singlet and triplet scattering lengths.