Quasiparticle chirality in Epitaxial Graphene Probed at the Nanometer Scale

Ivan Brihuega (1) , Pierre Mallet (2) , Cristina Bena (3) , Sangita Bose (1) , Christian Michaelis (1) , Lucia Vitali (1) , François Varchon , Laurence Magaud (4) , Klaus Kern (1, 5) , Jean-Yves Veuillen (2)

1 Max-Planck-Institut für Festkörperforschung
2 NEEL - QuNES - Nano-Electronique Quantique et Spectroscopie
3 IPHT - Institut de Physique Théorique - UMR CNRS 3681
4 NEEL - Quan2m - Interactions modulables dans des états quantiques 2D
5 EPFL - Ecole Polytechnique Fédérale de Lausanne

Graphene exhibits unconventional two-dimensional electronic properties resulting from the sym- metry 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 proper- ties at the nanometer scale. They are re°ected in the quantum interference pattern resulting from elastic scattering o® 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.

Mots clés: pseudospin; scattering; chirality; impurities; graphene; STM

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Ivan Brihuega, Pierre Mallet, Cristina Bena, Sangita Bose, Christian Michaelis, et al.. Quasiparticle chirality in Epitaxial Graphene Probed at the Nanometer Scale. Physical Review Letters, 2008, 101 (20), pp.206802. ⟨10.1103/PhysRevLett.101.206802⟩. ⟨hal-00339197⟩