1. IETP, Al-Farabi Kazakh National University, 71 Al-Farabi Ave., Almaty 050040, Kazakhstan
2. Department of Electrical Engineering and Information Science, Ruhr-University Bochum, D-44780 Bochum, Germany and Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, School of Physics, Dalian University of Technology, Dalian, China
3. Wigner Research Centre for Physics, H1121 Budapest, Hungary