diagram of the Bose-Hubbard Hamiltonian with long-range repulsive interactions. At half
filling one finds superfluidity and insulating solid phases. Depending on the relative sizes of
near-neighbor and next-near-neighbor interactions, this solid follows either a checkerboard
or a striped pattern. In neither case is there a coexistence with superfluidity. However, at
incommensurate densities “supersolid” phases appear with simultaneous diagonal and off …