1. Département de Physique, Lumiére et Matiére (PLUM), Institute Néel, CNRS, Grenoble INP, University Grenoble Alpes, Grenoble, France
2. Engineering Department, University of Cambridge, Cambridge, U.K.
3. Department of Electronic and Electrical Engineering, London Centre for Nanotechnology, University College London, London, U.K.
4. Fraunhofer Institute for Applied Solid State Physics IAF, Freiburg, Germany
5. Centro Nacional de Microelectronica (CNMCSIC), Carrer dels Tillers, Campus UAB, Barcelona, Spain
6. CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, Grenoble, France