Berlin 2018 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 27: Graphene: Electronic properties, structure and substrate interaction II (joint session O/TT)
O 27.8: Talk
Tuesday, March 13, 2018, 12:30–12:45, MA 043
Strong spin-orbit interaction in graphene/WSe2 probed at local scale — •Mikhail Fonin1, Felix Förschner1, Fabian Paschke1, Lena Stoppel1, Julia Tesch1, Yuriy Dedkov2,1, and Andor Kormányos1 — 1Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany — 2Department of Physics, Shanghai University, 200444 Shanghai, China
Deposition on transition metal dechalcogenide substrates allow to considerably modify the strength of spin-orbit interaction (SOI) in graphene, as shown in recent magnetotransport experiments [1,2]. Here we investigate structure and electronic properties of graphene on tungsten diselenide (WSe2) by means of scanning tunneling microscopy and spectroscopy. In external magnetic field local spectroscopic measurements reveal pronounced Landau level sequences on graphene/WSe2. Detailed analysis of the obtained tunneling spectra shows that each Landau level is split into subpeaks, where the splitting strength grows with increasing magnetic fields. We attribute the splittings to the manifestation of substrate induced SOI in graphene. A comparison of the experimental splitting strengths with the those yielded by a spin-dependent low-energy effective Hamiltonian allows the determination of the SOI coupling constants for the Rashba term and the so-called spin-valley coupling term. Furthermore, we map the real space fluctuations of the SOI coupling strength which correlate with the variations of local electronic potential.
[1] Z. Wang et al., Nature Comm. 6, 8339 (2015). [2] Z. Wang et al. Phys. Rev. X 6, 041020 (2016).