Observations of superlattice Dirac points in one-dimensionally-rippled graphene on hexagonal BN using scanning tunneling spectroscopy

It has been predicted that superlattice potentials in graphene would induce new Dirac points due to lattice-induced chirality of charge carriers. In this talk, we present our experimental observations of new Dirac points in one-dimensionally-rippled graphene on hexagonal BN using scanning tunneling microscopy and spectroscopy. The ripples, formed by thermal cycles, showed two new Dirac points of which energy levels were proportional to 1/L, where L was the period of a ripple, in agreement with theoretical predictions. Our study shows that one-dimensional periodic potential is an accessible component for controlling electronic properties of graphene.