Patterned Supersolids in Dipolar Bose Systems

We study by means of first-principle quantum Monte Carlo simulations the ground state phase diagram of a system of dipolar bosons with aligned dipole moments, and with the inclusion of a two-body repulsive potential of varying range. The system is shown to display a supersolid phase in a relatively broad region of the phase diagram, featuring different crystalline patterns depending on the density and on the range of the repulsive part of the interaction (scattering length). The supersolid phase is sandwiched between a classical crystal of parallel filaments and a homogeneous superfluid phase. We show that a "roton" minimum appears in the elementary excitation spectrum of the superfluid as the system approaches crystallization. The predictions of this study are in quantitative agreement with recent experimental results.