1. School of Microelectronics and Physics, Hunan University of Technology and Business 1 , Changsha 410205, China
2. Department of Physics, National University of Defense Technology 2 , Changsha 410073, China
3. Department of Nuclear Science and Technology, National University of Defense Technology 3 , Changsha 410073, China
4. Center for Advanced Material Diagnostic Technology, Shenzhen Technology University 4 , Shenzhen 518118, China