Pair condensation of bosonic atoms induced by optical lattices

We design a model of correlated hopping for bosonic atoms in optical lattices. Such a model exhibits three kinds of phases: a Mott insulator, a charge density wave, and a pair quasicondensate. One possible implementation of the model is based on two-state atoms embedded in an optical superlattice and having state-dependent interactions. Contrary to other models of pairing, correlated hopping is not a perturbative effect and should be observable in generalizations of current experiments.