Topology and Exchange Interaction in Rhombohedral Pentalayer Graphene

Rhombohedral pentalayer graphene, consisting of five ABC-stacked layers, has emerged as a versatile platform for correlated and topological phases. Its nearly flat bands near charge neutrality make it highly susceptible to interactions under perpendicular displacement field and doping. Recent experiments reveal insulating states at neutrality, symmetry-breaking metals upon doping, and quantum anomalous Hall phases with Chern numbers C=3 and C=5 We develop a microscopic framework combining tight-binding and Hartree-Fock methods to account for these phenomena. Our analysis shows how exchange-driven symmetry breaking, interlayer charge polarization, and band inversion generate insulating gaps, reduced Fermi-surface degeneracies, and topological transitions. This unified mean-field picture captures the interplay of interaction and topology in pentalayer graphene, offering insight into the mechanisms behind insulating behavior, flavor symmetry breaking, and quantum anomalous Hall states.