Dirac cones and minigaps for graphene on Ir(111)

Phys Rev Lett. 2009 Feb 6;102(5):056808. doi: 10.1103/PhysRevLett.102.056808. Epub 2009 Feb 6.

Abstract

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 moiré 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.