1. Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education) School of Physics DUT‐BSU Joint Institute Dalian University of Technology Dalian 116024 P. R. China
2. School of Physics and Information Technology Shaanxi Normal University Xi'an 710062 P. R. China
3. School of Physics Dalian University of Technology Dalian 116024 P. R. China
4. School of Microelectronics Dalian University of Technology Dalian 116024 P. R. China
5. School of Physics and Materials Engineering Dalian Minzu University Dalian 116600 P. R. China