1. School of Physics, Dalian University of Technology, Dalian 116024, China
2. DUT-BSU Joint Institute, Dalian University of Technology, Dalian 116024, China
3. College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
4. Belarusian State University, Minsk 220030, Belarus
5. B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk 220072, Belarus