"Probing substrate effects in the carbon-projected band structure of graphene on Pt(111) through resonant inelastic x-ray scattering"

Srivats Rajasekaran: Sarp Kaya, Toyli Anniyev, Hirohito Ogasawara, and Anders Nilsson; Physical Review B, 01/12/12.

Additional Authors: Sarp Kaya, Toyli Anniyev, Hirohito Ogasawara, and Anders Nilsson

Abstract:

The unoccupied and occupied σ and π bands of graphene on Pt(111) were measured using near-edge x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) at the carbon K edge. Elemental specificity and crystal-momentum conservation allows for detection of the dispersive band structure. In addition to features arising from the band structure of free-standing graphene, signatures of symmetry breaking were identified in XAS and in RIXS for excitation around the Fermi level. These additional features are proposed to derive from weak graphene-substrate interactions which manifest as substrate hybridization and surface umklapp processes due to Moiré superlattice vectors.