How can we understand heteroepitaxial growth modes with a computer simulation? (A perspective on the article, “heteroepitaxial growth modes with dislocations in a two-dimensional elastic lattice model”)

We use scanning tunneling spectroscopy (STS) at low temperatures to investigate the local electronic structure of mono- and bilayer graphene grown epitaxially on SiC(0 0 0 1). Already for monolayer graphene, a gap opening is observed in the π-bands at the Dirac point. The gap size is spatially modulated with the ( 6 3 × 6 3 ) R 30 ° periodicity of the interface structure. We ascribe this effect to a spatially dependent interface potential, which is imprinted into the graphene layer. For bilayer graphene the Dirac gap has a constant size, but a spatially localized mid-gap state is observed within. For both, gap state and π-bands the intensities are strongly modulated with the atomic periodicity of graphene.