Strongly correlated quantum systems can exhibit exotic behavior controlled by topology. We predict that the \nu=1/2 fractional Chern insulator arises naturally in a two-dimensional array of driven, dipolar-interacting spins. As a specific implementation, we analyze how to prepare and detect synthetic gauge potentials for the rotational excitations of ultra-cold polar molecules trapped in a deep optical lattice. While the orbital motion of the molecules is pinned, at finite densities, the rotational excitations form a fractional Chern insulator. We present a detailed experimental blueprint for KRb, and demonstrate that the energetics are consistent with near-term capabilities. Prospects for the realization of such phases in solid-state dipolar systems are discussed as are their possible applications.
@article{arxiv.1212.4839,
title = {Realizing Fractional Chern Insulators with Dipolar Spins},
author = {Norman Y. Yao and Alexey V. Gorshkov and Chris R. Laumann and Andreas M. Läuchli and Jun Ye and Mikhail D. Lukin},
journal= {arXiv preprint arXiv:1212.4839},
year = {2013}
}