Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5424434 | Surface Science | 2008 | 4 Pages |
Abstract
We use scanning tunneling spectroscopy (STS) at low temperatures to investigate the local electronic structure of mono- and bilayer graphene grown epitaxially on SiC(0 0 0 1). Already for monolayer graphene, a gap opening is observed in the Ï-bands at the Dirac point. The gap size is spatially modulated with the (63Ã63)R30° periodicity of the interface structure. We ascribe this effect to a spatially dependent interface potential, which is imprinted into the graphene layer. For bilayer graphene the Dirac gap has a constant size, but a spatially localized mid-gap state is observed within. For both, gap state and Ï-bands the intensities are strongly modulated with the atomic periodicity of graphene.
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Authors
L. Vitali, C. Riedl, R. Ohmann, I. Brihuega, U. Starke, K. Kern,