Quantum magnetism with multicomponent polar molecules in an optical   lattice
  We consider bosonic dipolar molecules in an optical lattice prepared in a mixture of different rotational states. The 1/r^3 interaction between molecules for this system is produced by exchanging a quantum of angular momentum between two molecules. We show that the Mott states of such systems have a large variety of non-trivial spin orderings including a state with ordering wave vector that can be changed by tilting the lattice. As the Mott insulating phase is melted, we also describe several exotic superfluid phases that will occur. 
Ryan Barnett, Dmitry Petrov, Mikhail Lukin, Eugene Demler