Simulating the Haldane model in ultraclean GaAs heterostructures

The Haldane model represents the minimal lattice-based realization of a Chern insulator, exhibiting a quantized Hall conductance in the absence of Landau levels. Despite its conceptual elegance, the implementation in crystalline solids of the requisite pattern of Peierls phases breaking time-reversal symmetry remains experimentally demanding. In this work, we theoretically investigate the possibility to simulate the Haldane model in ultra-clean GaAs/AlGaAs heterostructures. Our proposal relies on recent experiments in which a high-mobility two-dimensional electron gas is subject to a gate-defined honeycomb electrostatic potential and a laterally periodic magnetic field generated by patterned ferromagnetic structures. The combined electrostatic and magnetic superlattices furnish a viable route to emulate the topological properties of the Haldane model.