Faculty of Physics, University of Vienna, Strudlhofgasse 4., Vienna, A-1090, Austria. peter.szirmai@epfl.ch.
Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Spintronics Research Group (PROSPIN), PO Box 91, H-1521, Budapest, Hungary. peter.szirmai@epfl.ch.
Laboratory of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland. peter.szirmai@epfl.ch.