Defect-induced supersolidity with soft-core Bosons
We determine the zero-temperature phase diagram of two-dimensional Bosons with finite-range soft-core interactions. For high particle densities, we demonstrate that the ground state can be a commensurate density-wave-type supersolid. For low densities, the system is shown to form a solid in which superfluidity is provided by delocalized zero-point defects. This provides the first example of continuous-space supersolidity consistent with the Andreev-Lifshitz-Chester scenario.