Quantum anomalous Hall state from spatially decaying interactions on the decorated honeycomb lattice

The quantum anomalous Hall effect can, in principle, be driven entirely by interparticle interactions into a new phase of matter called the topological Mott insulator. Calculations to date have shown that this effect can arise in simple models only when the interaction strength between particles is not spatially decaying. Such interactions are typically unphysical. Here, the authors study particles in a decorated honeycomb lattice to find that spatially decaying interactions do in fact lead to a topological Mott insulator with a quantum anomalous Hall effect. The results set the stage for realizing interaction-driven topological effects in quantum matter.