Two-photon photoassociation spectroscopy of CsYb : ground-state interaction potential and interspecies scattering lengths.

We perform two-photon photoassociation spectroscopy of the heteronuclear CsYb molecule to measure the binding energies of near-threshold vibrational levels of the X 2+ 1/2 molecular ground state. We report results for 133Cs170Yb, 133Cs173Yb, and 133Cs174Yb, in each case determining the energy of several vibrational levels including the least-bound state. We fit an interaction potential based on electronic structure calculations to the binding energies for all three isotopologs and find that the ground-state potential supports 77 vibrational levels. We use the fitted potential to predict the interspecies s-wave scattering lengths for all seven Cs+Yb isotopic mixtures