7 research outputs found
Epitaxial graphene: a new material
Graphene, a two-dimensional sheet of sp2-bonded car-bon arranged in a honeycomb lattice, is not only the building block of fullerenes, carbon nano tubes (CNTs) and graphite, it also has interesting properties, which have caused a flood of activities in the past few years. The possibility to grow graphitic films with thick-nesses down to a single graphene layer epitaxially on SiC{0001} surfaces is promising for future applications. The two-dimensional nature of epitaxial graphene films make them ideal objects for surface science techniques such as photoelectron spectroscopy, low-energy electron diffraction, and scanning probe microscopy. The present article summarizes results from recent photoemission studies covering a variety of aspects such as the growth of epitaxial graphene and few layer graphene, the elec
Electron-Phonon Coupling in Highly-Screened Graphene
Photoemission studies of graphene have resulted in a long-standing
controversy concerning the strength of the experimental electron-phonon
interaction in comparison with theoretical calculations. Using high-resolution
angle-resolved photoemission spectroscopy we study graphene grown on a copper
substrate, where the metallic screening of the substrate substantially reduces
the electron-electron interaction, simplifying the comparison of the
electron-phonon interaction between theory and experiment. By taking the
nonlinear bare bandstructure into account, we are able to show that the
strength of the electron-phonon interaction does indeed agree with theoretical
calculations. In addition, we observe a significant bandgap at the Dirac point
of graphene.Comment: Submitted to Phys. Rev. Lett. on July 20, 201
Symmetry Breaking in Few Layer Graphene Films
Recently, it was demonstrated that the quasiparticle dynamics, the
layer-dependent charge and potential, and the c-axis screening coefficient
could be extracted from measurements of the spectral function of few layer
graphene films grown epitaxially on SiC using angle-resolved photoemission
spectroscopy (ARPES). In this article we review these findings, and present
detailed methodology for extracting such parameters from ARPES. We also present
detailed arguments against the possibility of an energy gap at the Dirac
crossing ED.Comment: 23 pages, 13 figures, Conference Proceedings of DPG Meeting Mar 2007
Regensburg Submitted to New Journal of Physic
Dirac electrons in graphene-based quantum wires and quantum dots
In this paper we analyse the electronic properties of Dirac electrons in
finite-size ribbons and in circular and hexagonal quantum dots made of
graphene.Comment: Contribution for J. Phys.: Cond. Mat. special issue on graphene
physic