  We have systematically studied the hard-core Bose-Hubbard model with
correlated hopping on a triangular lattice using density-matrix renormalization
group method. A rich ground state phase diagram is determined. In this phase
diagram there is a supersolid phase and a pair superfluid phase due to the
interplay between the ordinary frustrated boson hopping and an unusual
correlated hopping. In particular, we find that the quantum phase transition
between the supersolid phase and the pair superfluid phase is continuous.
