1207.4479 (Norman Y. Yao et al.)

Topological Flat Bands from Dipolar Spin Systems    [PDF]

Norman Y. Yao, Chris R. Laumann, Alexey V. Gorshkov, Steven D. Bennett, Eugene Demler, Peter Zoller, Mikhail D. Lukin

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.

View original: http://arxiv.org/abs/1207.4479