Exploring interlayer Dirac cone coupling in commensurately rotated few-layer graphene on SiC(000-1)

Abstract : We investigate electronic band-structure images in reciprocal space of few-layer graphene epitaxially grown on SiC(000-1). In addition to the observation of commensurate rotation angles of the graphene layers, the k-space images recorded near the Fermi edge highlight structures originating from diffraction of the Dirac cones due to the relative rotation of adjacent layers. The 21.9° and 27° rotation angles between two sheets of graphene are responsible for a periodic pattern that can be described with a superlattice unit cells. The superlattice generates replicas of Dirac cones with smaller wave vectors, because of a Brillouin zone folding. Copyright © 2014 John Wiley & Sons, Ltd.