  We design a model of correlated hopping for bosonic atoms in optical
lattices. Such model exhibits three kinds of phases, comprehending a Mott
insulator, a charge density wave and a pair quasi-condensate. The
implementation of the model relies on two-state atoms embedded in
state-dependent lattices and having spin-dependent interactions. Contrary to
other models of pairing, our design is not based on perturbative effects and
should be observable in current experiments.
