1. Faculty of Physics, M.V. Lomonosov Moscow State University, 1, bldg.2, Leninskie Gory, Moscow 119991, Russian Federation
2. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38, Vavilov Str., Moscow 119991, Russian Federation
3. Adámas Nanotechnologies, Inc., 8100 Brownleigh Dr, Raleigh, North Carolina 27617, United States