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O: Fachverband Oberflächenphysik
O 35: Poster Session I (Metal, semiconductor and oxide substrates: structure and adsorbates; Graphene)
O 35.77: Poster
Dienstag, 12. März 2013, 18:15–21:45, Poster B1
Band renormalization, mini-cones and Fermi surface discontinuities in epitaxial graphene on SiC(0001) by Cu intercalation — •Stiven Forti1, Konstantin V. Emtsev1, Alexei A. Zakharov2, Camilla Coletti3, and Ulrich Starke1 — 1Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany — 2MAX Lab, Lund University, Box 118, Lund, 22100, Sweden — 3Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
The interaction of graphene with transition metals as well as the effects of a periodic perturbation on the graphene’s band structure are fields of great interest. In this work we present photoemission spectroscopy (PES), low-energy electron diffraction (LEED) and microscopy (LEEM) to study the effects of an ordered layer of Cu atoms intercalated under epitaxial graphene (EG) on SiC(0001). By means of angle-resolved photoelectron spectroscopy (ARPES) measurements, we observed that the intercalated graphene is effectively decoupled from the substrate and the interfacial Cu layer imposes both a strong n-doping and a periodic potential, which deeply affect the graphene’s band structure. The site-specific interaction between Cu and graphene, together with the chiral nature of the graphene’s carriers, produce the development of minicones (mCs) located along the boundaries of the graphene’s Brillouin zone. Mini band-gaps are observed at the mCs vertexes and the Fermi surface exhibits discontinuities caused by the emergence of new electronic states associated with the mCs.