The prospects of forming ultracold molecules in $^2\Sigma$ states by magnetoassociation of alkali-metal atoms with Yb

摘要

We explore the feasibility of producing ultracold diatomic molecules withnonzero electric and magnetic dipole moments by magnetically associating twoatoms, one with zero electron spin and one with nonzero spin. Feshbachresonances arise through the dependence of the hyperfine coupling oninternuclear distance. We survey the Feshbach resonances in diatomic systemscombining the nine stable alkali-metal isotopes with those of Yb, focussing onthe illustrative examples of RbYb and CsYb. We show that the resonance widthsmay expressed as a product of physically comprehensible terms in the frameworkof Fermi's Golden Rule. The resonance widths depend strongly on the backgroundscattering length, which may be adjusted by selecting the Yb isotope, and onthe hyperfine coupling constant and the magnetic field. In favorable cases theresonances may be over 100 mG wide.