Near-edge x-ray absorption fine structure investigation of graphene
  We report the near-edge x-ray absorption fine structure (NEXAFS) spectrum of a single layer of graphite (graphene) obtained by micromechanical cleavage of Highly Ordered Pyrolytic Graphite (HOPG) on a SiO2 substrate. We utilized a PhotoEmission Electron Microscope (PEEM) to separately study single- double- and few-layers graphene (FLG) samples. In single-layer graphene we observe a splitting of the pi* resonance and a clear signature of the predicted interlayer state. The NEXAFS data illustrate the rapid evolution of the electronic structure with the increased number of layers. 
D. Pacil\'e, M. Papagno, A. Fraile Rodr\'iguez, M. Grioni, and L.   Papagno, \c{C}. \"O. Girit, J. C. Meyer, G. E. Begtrup, ...