1. B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine, 47 Nauky Ave., Kharkiv, 61103, Ukraine
2. Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
3. L.V. Kirensky Institute of Physics, Federal Research Center KSC Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk 660036, Russia