Feshbach resonances in $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ mixtures and refined molecular potentials for the NaK molecule

TL;DR

This paper reports detailed measurements of Feshbach resonances in the $^{23}$Na+$^{39}$K mixture, refining molecular potentials for NaK and enhancing understanding of interspecies interactions in ultracold gases.

Contribution

The study provides new experimental data on Feshbach resonances and refines the NaK molecular potentials, enabling better control of interspecies interactions in ultracold mixtures.

Findings

14 Feshbach resonances identified

4 zero crossings of scattering length observed

Refined NaK molecular potentials achieved

Abstract

We present a detailed study of interspecies Feshbach resonances of the bosonic $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ mixture for magnetic fields up to $750 \, \mathrm{G}$ in various collision channels. A total of fourteen Feshbach resonances are reported, as well as four zero crossings of the scattering length and three inelastic two-body loss features. We use the observed magnetic field locations of the resonant features together with the known data on $^{23}\mathrm{Na}+$$^{40}\mathrm{K}$ to refine the singlet and triplet ground state potentials of NaK and achieve a consistent description of Feshbach resonances for both, the Bose-Bose mixture of $^{23}\mathrm{Na}+$$^{39}\mathrm{K}$ as well as the Bose-Fermi mixture of $^{23}\mathrm{Na}+$$^{40}\mathrm{K}$.