Molecular vortex generated from an atom-molecule dark state

We consider a Raman photoassociation model in a field configuration in which a Gaussian and a first-order Laguerre Gaussian laser field are applied between the bound-bound and free-bound transitions, respectively. We show that such a configuration can lead to a coherent population trapping superposition of an atomic condensate and a ground molecular vortex of unit winding number. We develop stimulated Raman adiabatic passages that minimize the effect of mean-field shifts due to collisions, for optimal conversion of an atomic condensate into a ground molecular vortex.