Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 22: Graphene 2 (Joint Session with TT)
HL 22.8: Vortrag
Dienstag, 23. März 2010, 11:30–11:45, H21
Giant Rashba splitting in Au-intercalated graphene — •Dmitry Marchenko1, Andrei Varykhalov1, Markus R. Scholz1, Oliver Rader1, Gustav Bihlmayer2, and Emmanuel I. Rashba3 — 1Helmholtz-Zentrum Berlin für Materialien und Energie — 2Institut für Festkörperforschung, Forschungszentrum Jülich — 3Department of Physics and Center for Nanoscale Systems, Harvard University
The use of graphene for spin transport [1] is generally connected to the small size of its intrinsic spin-orbit coupling leading to a splitting of the order of 0.01 to 0.1 meV [2]. This small value can be enhanced by a Rashba effect from a substrate [3] which couples graphene spin and pseudospin [4]. For the graphene-Au interface created by intercalation of a Au monolayer between graphene and Ni(111) a spin-orbit splitting of Δso ∼ 13 meV was measured [3]. By optimized sample preparation, we obtain now Δso values of the order of 100 meV near the Fermi energy by spin- and angle-resolved photoelectron spectroscopy, i. e., an enhancement by 3 to 4 orders of magnitude relative to the intrinsic values. We discuss the origin of this large splitting with the help of ab initio density functional calculations using the generalized gradient approximation.
[1] N. Tombros et al., Nature 448, 571 (2007)
[2] J. C. Boettger and S. B. Trickey, Phys. Rev. B 75, 121402(R) (2007); C. L. Kane and E. J. Mele, Phys. Rev. Lett. 95, 226801 (2005)
[3] A. Varykhalov et al., Phys. Rev. Lett. 101, 157601 (2008)
[4] E. I. Rashba, Phys. Rev. B 79, 161409(R) (2009)