1. Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia, Via Barsanti 14, Arnesano 73010, Italy
2. Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via Re David 200, Bari 70125, Italy
3. Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, Minnesota, United States
4. Chair in Hybrid Nanosystems, Nanoinstitut Munich, Faculty of Physics, Ludwig-Maximilians Universität München, Königinstrasse 10, München 80539, Germany
5. Experimental Solid State Physics Group, Department of Physics, Imperial College London, London SW7 2AZ, UK