Existence and stability of coupled atomic-molecular Bose-Einstein condensates

We analyze a mean-field model of an atomic Bose-Einstein condensate parametrically coupled to a molecular condensate via a Raman photoassociation process. We show that an interplay of nonlinear interspecies and intraspecies interactions leads to the formation of mutually trapped states of a hybrid condensate, which are spatially localized and dynamically stable even without a trap.