1. Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, CH-8093 Zürich, Switzerland
2. CSEM SA, Jaquet-Droz 1, CH-2002 Neuchâtel, Switzerland
3. Brick Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907-2057, United States
4. Department of Electrical Engineering, EPF Lausanne, CH-1015 Lausanne, Switzerland
5. Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112, United States