Feshbach resonances and molecule formation in ultracold mixtures of Rb andYb(P3)atoms

Abstract

We have investigated magnetically tunable Feshbach resonances in ultracold collisions of Rb with Yb in its metastable ${}^{3}{P}_{2}$ and ${}^{3}{P}_{0}$ states, using coupled-channel scattering and bound-state calculations. For the ${}^{3}{P}_{2}$ state, we find sharp resonances when both atoms are in their lowest Zeeman sublevels. However, these resonances are decayed by inelastic processes that produce Yb atoms in ${}^{3}{P}_{1}$ and ${}^{3}{P}_{0}$ states. The molecules that might be produced by magnetoassociation at the ${}^{3}{P}_{2}$ thresholds can decay by similar pathways and would have lifetimes no more than a few microseconds. For the ${}^{3}{P}_{0}$ state, by contrast, there are resonances that are promising for magnetoassociation. There are resonances due to both rotating and nonrotating molecular states that are significantly stronger than the analogous resonances for $\mathrm{Yb}{(}^{1}S$). The ones due to rotating states are denser in magnetic field; in contrast to $\mathrm{Yb}{(}^{1}S$), they exist even for bosonic isotopes of $\mathrm{Yb}{(}^{3}{P}_{0}$).