Dirac Cones and Minigaps for Graphene on Ir(111)
  Epitaxial graphene on Ir(111) prepared in excellent structural quality is investigated by angle-resolved photoelectron spectroscopy. It clearly displays a Dirac cone with the Dirac point shifted only slightly above the Fermi level. The moire resulting from the overlaid graphene and Ir(111) surface lattices imposes a superperiodic potential giving rise to Dirac cone replicas and the opening of minigaps in the band structure. 
I. Pletikosic, M. Kralj, P. Pervan, R. Brako, J. Coraux, A. T.   N'Diaye, C. Busse, and T. Michely