Feshbach resonances and molecule formation in ultracold mixtures of Rb and Yb($^3$P) atoms

TL;DR

This study explores magnetically tunable Feshbach resonances in ultracold Rb-Yb($^3$P) mixtures, identifying promising resonances for molecule formation and analyzing decay pathways affecting molecule lifetimes.

Contribution

It provides the first detailed theoretical analysis of Feshbach resonances in Rb-Yb($^3$P) systems, highlighting potential for molecule creation and the impact of inelastic decay channels.

Findings

Sharp resonances found in $^3$P$_2$ state but with short molecule lifetimes.

Promising resonances identified in $^3$P$_0$ state for magnetoassociation.

Resonances due to rotating states are denser and exist for bosonic Yb isotopes.

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 non-rotating molecular states that are significantly stronger than the analogous resonances for Yb($^1$S). The ones due to rotating states are denser in magnetic field; in contrast to Yb($^1$S), they exist even for bosonic isotopes of Yb($^3$P$_0$).