1. Department of Physics, Dalian University of Technology 1 , Dalian 116024, China
2. School of Physics and Astronomy, China West Normal University 2 , Nanchong 637009, China
3. DUT-BSU Joint Institute, Dalian University of Technology 3 , Dalian 116024, China
4. State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 4 , Dalian 116023, China
5. Physics Department, Belarusian State University 5 , Minsk, Belarus
6. Department of Information Engineering and Electrical and Applied Mathematics/DIEM, University of Salerno 6 , Fisciano, SA, Italy