Field-induced insulating states in a graphene superlattice

When graphene is aligned on top of hBN and subjected to a magnetic field, `cloning' of Dirac fermions takes place each time rational values of flux quanta thread the superlattice unit cell. Here, the authors use high-field magnetotransport up to 35 T to address the emergence of insulating replica states in a 15-nm graphene/hBN superlattice. An analysis in the framework of Landau quantization of the replica particles in an effective magnetic field allows us to determine their energy-momentum dispersion, which is renormalized compared with the original electron states.