Realizing Fractional Chern Insulators with Dipolar Spins

TL;DR

This paper predicts the emergence of fractional Chern insulators in a 2D array of driven dipolar spins, proposing a feasible experimental setup with ultra-cold polar molecules to realize topologically ordered phases.

Contribution

It introduces a novel approach to realize fractional Chern insulators using dipolar spins and provides a detailed experimental blueprint for ultra-cold polar molecules.

Findings

Feasible experimental setup with KRb molecules.

Energetics compatible with near-term capabilities.

Discussion of solid-state realization prospects.

Abstract

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.