@article {1201, title = {Topological Flat Bands from Dipolar Spin Systems}, journal = {Physical Review Letters}, volume = {109}, year = {2012}, month = {2012/12/26}, abstract = { We propose and analyze a physical system that naturally admits two-dimensional topological nearly flat bands. Our approach utilizes an array of three-level dipoles (effective S = 1 spins) driven by inhomogeneous electromagnetic fields. The dipolar interactions produce arbitrary uniform background gauge fields for an effective collection of conserved hardcore bosons, namely, the dressed spin-flips. These gauge fields result in topological band structures, whose bandgap can be larger than the corresponding bandwidth. Exact diagonalization of the full interacting Hamiltonian at half-filling reveals the existence of superfluid, crystalline, and supersolid phases. An experimental realization using either ultra-cold polar molecules or spins in the solid state is considered. }, doi = {10.1103/PhysRevLett.109.266804}, url = {http://arxiv.org/abs/1207.4479v3}, author = {Norman Y. Yao and Chris R. Laumann and Alexey V. Gorshkov and Steven D. Bennett and Eugene Demler and Peter Zoller and Mikhail D. Lukin} }