L. Magaud

Electronic Structure of Epitaxial Graphene Layers on SiC: Effect of the Substrate

A strong substrate-graphite bond is found in the first all-carbon layer by density functional theory calculations and x-ray diffraction for few graphene layers grown epitaxially on SiC. This first layer is devoid of graphene electronic properties and acts as a buffer layer. The graphene nature of the film is recovered by the second carbon layer grown on both the (0001) and (0001[over]) 4H-SiC surfaces. We also present evidence of a charge transfer that depends on the interface geometry. Hence the graphene is doped and a gap opens at the Dirac point after three Bernal stacked carbon layers are formed.

Localization of dirac electrons in rotated graphene bilayers.

For Dirac electrons the Klein paradox implies that the confinement is difficult to achieve with an electrostatic potential although it can be of great importance for graphene-based devices. Here, ab initio and tight-binding approaches are combined and show that the wave function of Dirac electrons can be localized in rotated graphene bilayers due to the Moire pattern. This localization of wave function is maximum in the limit of the small rotation angle between the two layers.

Quasiparticle Chirality in Epitaxial Graphene Probed at the Nanometer Scale

Graphene exhibits unconventional two-dimensional electronic properties resulting from the symmetry of its quasiparticles, which leads to the concepts of pseudospin and electronic chirality. Here, we report that scanning tunneling microscopy can be used to probe these unique symmetry properties at the nanometer scale. They are reflected in the quantum interference pattern resulting from elastic scattering off impurities, and they can be directly read from its fast Fourier transform. Our data, complemented by theoretical calculations, demonstrate that the pseudospin and the electronic chirality in epitaxial graphene on SiC(0001) correspond to the ones predicted for ideal graphene.

Numerical studies of confined states in rotated bilayers of graphene

Rotated graphene multilayers form a new class of graphene-related systems with electronic properties that drastically depend on the rotation angles. It has been shown that bilayers behave like two isolated graphene planes for large rotation angles. For smaller angles, states in the Dirac cones belonging to the two layers interact resulting in the appearance of two Van Hove singularities. States become localized as the rotation angle decreases and the two Van Hove singularities merge into one peak at the Dirac energy. Here we go further and consider bilayers with very small rotation angles. In this case, well-defined regions of AA stacking exist in the bilayer supercell and we show that states are confined in these regions for energies in the [

Elementary processes of H2 plasma-graphene interaction: A combined molecular dynamics and density functional theory study

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Interface structure of graphene on SiC: an ab initio and STM approach

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Dirac Particles in Epitaxial Graphene Films Grown on SiC

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Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 3) : a scanning tunneling microscopy study.

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Universal classification of twisted, strained and sheared graphene moiré superlattices.

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In, Sn dimers on Si(100)2×1 surface: ab initio calculations and STM experiments

the interplane mean interaction. As a consequence, the local densities of states show discrete peaks for energies different from the Dirac energy.