Study on the high spectral intensity at the Dirac energy of single-layer graphene on an SiC substrate

Abstract

We have investigated electron band structure of epitaxially grown graphene on an SiC(0001) substrate using angle-resolved photoemission spectroscopy. In single-layer graphene, abnormal high spectral intensity is observed at the Dirac energy whose origin has been questioned between in-gap states induced by the buffer layer and plasmaron bands induced by electron-plasmon interactions. With the formation of double-layer graphene, the Dirac energy does not show the high spectral intensity any longer different from the single-layer case. The inconsistency between the two systems suggests that the main ingredient of the high spectral intensity at the Dirac energy of single-layer graphene is the electronic states originating from the coupling of the graphene $\pi$ bands to the localized $\pi$ states of the buffer layer, consistent with the theoretical prediction on the presence of in-gap states.

11 pages, 5 figures

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• The electronic properties of graphene
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Cited by in corpus (1)

• Emergence of Kondo resonance in graphene intercalated with cerium