title: Quantum phases of cold polar molecules in 2D optical lattices.
abstract: We study the quantum phases of hard-core bosonic polar molecules on a two-dimensional square lattice interacting via repulsive dipole-dipole interactions. In the limit of small tunneling, we find evidence for a devil's staircase, where Mott solids appear at rational fillings of the lattice. For finite tunneling, we establish the existence of extended regions of parameters where the ground state is a supersolid, obtained by doping the solids either with particles or vacancies. We discuss the effects of finite temperature and finite-size confining potentials as relevant to experiments.
authors.affiliation: ITAMP, Harvard-Smithsonian Center of Astrophysics, Cambridge, Massachusetts 02138, USA.
authors.forename: B
authors.initials: B
authors.lastname: Capogrosso-Sansone
authors.forename: C
authors.initials: C
authors.lastname: Trefzger
authors.forename: M
authors.initials: M
authors.lastname: Lewenstein
authors.forename: P
authors.initials: P
authors.lastname: Zoller
authors.forename: G
authors.initials: G
authors.lastname: Pupillo