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

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}$.