Berlin 2012 – wissenschaftliches Programm
MA 43.2: Hauptvortrag
Donnerstag, 29. März 2012, 15:30–16:00, H 1012
Long spin relaxation times in epitaxial graphene on SiC(0001) — •Thomas Maassen1, Jan Jasper van den Berg1, Natasja IJbema1, Felix Fromm2, Thomas Seyller2, Rositsa Yakimova3, and Bart Jan van Wees1 — 1Zernike Institute for Advanced Materials, University of Groningen, The Netherlands — 2Lehrstuhl für Technische Physik, Universität Erlangen-Nürnberg, Germany — 3Department of Physics, Chemistry and Biology (IFM), Linköping University, Sweden
Spin transport in graphene draws great interest because of recent promising measurements at room temperature (RT). At the same time the limiting factor for spin relaxation seems to be the substrate. By replacing the commonly used SiO2 substrate we aim to observe improved spin transport. We developed an easy process to prepare lateral spin-valve devices on epitaxial grown monolayer graphene on SiC(0001), that enables us to upscale the production to wafer size. We examine the spin transport properties of this material by performing nonlocal spin-valve and Hanle spin precession measurements. We observe the longest spin relaxation time τS in single layer graphene at RT (1.5 ns) and T=4.2 K (2.3 ns), while the spin diffusion coefficient is strongly reduced by nearly 2 orders of magnitude. The increase in τS is probably related to the changed substrate, while the small value for DS is until now unexplained. Nevertheless, the high values for τS, combined with the easy production method on a large scale, clear the way for graphene based spintronic devices and applications in the future.