Coherent Molecular Vortex Generation from an Atomic Condensate

We consider a two-color photoassociation model in a field configuration in which the dump field is in a Gaussian mode while the pump field is in a first-order Laguerre Gaussian mode. We show that this configuration supports a nonlinear dark state, which is a coherent superposition between an atomic BEC and the ground molecular vortex state of winding number 1. We use this nonlinear dark state as the basis for developing a chipped stimulated Raman adiabatic passage that can lead to an efficient conversion of an atomic condensate into a ground molecular vortex while minimizing the particle loss via the excited molecular state.