  The low temperature phase diagram of Bose soft disks in two dimensions is
studied by numerical simulations. It is shown that a supersolid cluster phase
exists, within a range of the model parameters, analogous to that recently
observed for a system of aligned dipoles interacting via a softened potential
at short distance. These findings indicate that a long-range tail of the
interaction is unneeded to obtain such a phase, and that the soft-core
repulsive interaction is the minimal model for supersolidity.
