Feshbach resonances in the ultracold 6Li-173Yb mixtures*

The LiYb molecule is of current experimental interest due to its spin doublet ground state with both electric and magnetic dipole moments. Here, we develop a theoretical model to predict the location and width of Feshbach resonances in $^6$Li-$^{173}$Yb mixtures at ultracold temperatures by taking into account $R$-dependent hyperfine couplings. By using the non-relativistic configuration-interaction valance-bond (CI-VB) method, we, first, compute the hyperfine coupling constants as functions of internuclear separation. The short-range modification of the hyperfine couplings leads to narrow Feshbach resonances. Then we present quantum scattering calculations using the state-of-art {\it ab~initio} $^2\Sigma^+$ molecular potential, which has been adjusted to reproduce spectroscopic bound-state measurements. The calculated resonance widths, although small, are comparable to some of the successfully observed resonances in RbSr [1]. Finally, we describe the properties of the predicted $^6$Li$^{173}$Yb Feshbach resonances, offering a guide for current experimental measurements. [1] B. Vincent, C. Alessio, P. Benjamin, R. Lukas, S. Florian, P. S. \.{Z}uchowski and J. M. Hutson, Nature Phys. {\bf 14}, 881 (2018).