1. Fachbereich Mathematik/Informatik/Physik, Universität Osnabrück, 49076 Osnabrück, Germany
2. Faculty of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
3. Department of Applied Physics, Aalto University, Finland
4. Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa 920-1192, Japan