1. Chair for Photonics and Optoelectronics; Department of Physics and Center for Nanoscience (CeNS); Ludwig-Maximilians-Universität München; Amalienstraße 54 80799 Munich Germany
2. Nanosystems Initiative Munich (NIM); Schellingstraße 4 80799 Munich Germany
3. Soft Condensed Matter Group; Department of Physics and Center for Nanoscience (CeNS); Ludwig-Maximilians-Universität München; Geschwister-Scholl-Platz 1 80539 Munich Germany