Magnetically tunable Feshbach resonances in ultracold Li-Yb mixtures

TL;DR

This paper explores the formation of ultracold Li-Yb molecules via magnetoassociation, revealing narrow Feshbach resonances for even-mass Yb isotopes and significantly larger resonances for odd-mass isotopes due to hyperfine interactions.

Contribution

It identifies a new hyperfine coupling mechanism that enhances Feshbach resonances in fermionic Yb isotopes, advancing ultracold molecule formation techniques.

Findings

Feshbach resonances are extremely narrow for even-mass Yb isotopes.

Hyperfine coupling in odd-mass Yb isotopes produces larger Feshbach resonances.

Resonance sizes can be more than 100 times larger in fermionic Yb isotopes.

Abstract

We investigate the possibility of forming Li+Yb ultracold molecules by magnetoassociation in mixtures of ultracold atoms. We find that magnetically tunable Feshbach resonances exist, but are extremely narrow for even-mass ytterbium isotopes, which all have zero spin. For odd-mass Yb isotopes, however, there is a new mechanism due to hyperfine coupling between the electron spin and the Yb nuclear magnetic moment. This mechanism produces Feshbach resonances for fermionic Yb isotopes that can be more than 2 orders of magnitude larger than for the bosonic counterparts.