1. B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 47 Nauki Ave., Kharkov 61103, Ukraine
2. National Science Center, Kharkov Institute of Physics and Technology, National Academy of Sciences of Ukraine, 1 Akademicheskaya St., Kharkov 61108, Ukraine
3. Lomonosov Moscow State University, 1 Leninskie Gory St., Moscow 119991, Russia