Topological phases from dipolar interactions on kagome optical lattices

Topological phases identified by a quantum Hall effect are typically generated from an applied gauge field. But the quantum anomalous Hall effect can arise from a spontaneously broken time reversal symmetry even without an applied gauge field. While a number of proposals have been put forward to realize ordinary topological phases in quantum gas experiments, most of them require extra lasers (in addition to those generating the lattice) for creating effective gauge fields. Applied fields unfortunately lead to additional heating and losses, and, in realistic experiments, often makes it difficult to reach the low temperatures required to realize topological phases. Here, we propose a different system in which this problem is circumvented: dipolar fermions on a kagome optical lattice. We find that a quantum anomalous Hall phase naturally emerges in the \emph{absence} of artificial gauge fields, thus avoiding the additional lasers and the concomitant heating and losses. The complementary approaches of exact diagonalization and mean-field theory are used to establish the remarkable robustness of this phase and estimate parameters needed to observe it with dipolar fermions in a kagome optical lattice.