1. Institute for Electronics Microelectronics and Nanotechnology (IEMN), CNRS, University of Lille, Av. Poincaré, Villeneuve d'Ascq, France
2. Institut Parisien de Chimie Moléculaire (IPCM), CNRS, Sorbonne Université, 4 Place Jussieu, F-75005 Paris, France
3. EMPA, Transport at the Nanoscale Laboratory, 8600 Dübendorf, Switzerland
4. Dept. of Physics and Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
5. Department of Information Technology and Electrical Engineering, ETH Zurich, 8092 Zurich, Switzerland