Ultracold and ultrasoft: Defect-induced supersolidity and a glass phase of dipole-blockaded Bosons

Abstract:

We discuss the quantum phases and dynamics of two-dimensional Bosons with
finite-range soft-core interactions. In particular, 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. For strong enough interactions, we demonstrate the emergence of a
novel glass phase in purely isotropic, mono-dispersed gases. We discuss the
possibility to observe some of these phases with cold atomic and molecular
gases