1. V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41 prospect Nauky, 03028 Kyiv, Ukraine
2. Ioffe Institute, 194021 St.-Petersburg, Russian Federation
3. TFTC Ioffe R&D Center, 194021 St.-Petersburg, Russian Federation
4. Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3X7, Canada