1. Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316 Oslo, Norway
2. Norwegian Defence Research Establishment (FFI), P.O. Box 25, 2027 Kjeller, Norway
3. nSolution AS, Maries Gate 6, 0368 Oslo, Norway
4. Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
5. Institute of Micro- and Nanoelectronic Systems, Karlsruhe Institute of Technology, Hertzstr. 16, 76187 Karlsruhe, Germany
6. Nanoscience Center, Department of Physics, P.O. Box 35, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
7. Institute for Superconducting and Electronic Materials, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia