Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 4: Graphene I

O 4.8: Talk

Monday, March 26, 2012, 12:15–12:30, MA 041

Minigap isotropy and broken chiral symmetry in graphene with periodic corrugation — •Jaime Sánchez-Barriga, A. Varykhalov, D. Marchenko, M. R. Scholz, and O. Rader — Helmholtz-Zentrum Berlin

The chirality of charge carriers in graphene determines its peculiar scattering properties and in particular the avoided backscattering, predicted to be observable as the closing of minigaps in periodically corrugated graphene. By angle-resolved photoemission we show that the corrugated graphene layer that forms on Ir(111) exhibits isotropic minigaps which close nowhere in k-space, as expected for non-chiral particles. Artificially introducing an extra periodic superpotential by deposition of clusters with different compositions confirms the minigap isotropy indicating that the origin of this behavior is directly connected to the breaking of the chiral symmetry in the system.