1. Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028 Kyiv, Ukraine
2. Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, 14-b Metrolohichna street, 03680 Kyiv, Ukraine
3. V. Lashkariov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Prospect Nauky 41, 03028 Kyiv, Ukraine
4. Taras Shevchenko Kyiv National University, Physical Faculty, Prospect Akademika Hlushkova 4a, 03022 Kyiv, Ukraine
5. Institute of Low Temperature and Structure Research, PAS, 2 Okolna St., 50-422 Wroclaw, Poland
6. Taras Shevchenko Kyiv National University, Radiophysical Faculty, Prospect Akademika Hlushkova 4g, 03022 Kyiv, Ukraine