Polarization-dependent C K near-edge X-ray absorption fine-structure of graphene

We report the polarization-dependent C K photoabsorption spectra of single- and few-layer graphene (FLG) samples produced by micromechanical cleavage of highly ordered pyrolytic graphite (HOPG) on a SiO 2 substrate. We show that the unoccupied σ density of states of graphene and FLG strongly reflects the one measured on bulk HOPG, demonstrating the two-dimensional character of σ states as well as the very-weak interlayer couplings between planes. Moreover, our spectra taken with different polarization allow us to show the predicted hybrid nature of the interlayer state.