Scanning Tunneling Spectroscopy of Graphene on Hexagonal Boron Nitride

Recent work has found hexagonal boron nitride (hBN) to be a good substrate for graphene devices due to its ability to screen charged impurities in the underlying substrate and increase graphene mobility. We investigated graphene on hBN heterostructures using scanning tunneling microscopy and spectroscopy. Because hBN has the same bond structure as graphene with a slightly longer lattice constant, a rotationally dependent Moir\'{e} pattern is formed in graphene on hBN heterostructures. The Moir\'{e} pattern creates a weak periodic potential for the charge carriers in graphene. We performed an experimental and theoretical investigation of its effect on the local density of states. We observed a Moir\'{e} wavelength dependent modification of the local density of states in good agreement with theory predictions.