1. Department of Physics and Nanotechnology; Aalborg University; Skjernvej 4A Aalborg, 9220 Denmark
2. Institute of Problems of Mechanical Engineering; Russian Academy of Sciences; Bolshoi pr. 61 St. Petersburg 199178 Russia
3. St. Petersburg National Research University of Information Technologies; Mechanics and Optics (ITMO University); Kronverkskii pr. 49 St. Petersburg 197101 Russia
4. Ioffe Physical-Technical Institute; Russian Academy of Sciences; Politekhnicheskaya str. 26 St. Petersburg 194021 Russia
5. Interdisciplinary Nanoscience Center (iNANO); Aarhus University; Gustav Wieds Vej 14 Aarhus C 8000 Denmark