We present a comprehensive numerical study on the ground state phase diagram of the two-dimensional hard core bosonic extended Hubbard model with nearest (V1) and next nearest neighbor (V2) repulsions. In addition to the quantum solid and superfluid phases, we report the existence of a striped supersolid and three-quarter (quarter)-filled supersolid at commensurate density ρ=0.75 (0.25) due to the interplay of V1 and V2 interactions. The nature of the three-quarter-filled supersolid and the associated quantum solid will be discussed. The observed quantum phase transition between the two supersolids of different symmetries is found to be first order. ? 2008 The American Physical Society.
Relation:
Physical Review B - Condensed Matter and Materials Physics 77 (5) , art. no. 052506
