1. School of Physics and Materials, Nanchang University 1 , Nanchang 330031, People's Republic of China
2. College Physics and Electron Information, Nanchang Normal University 2 , Nanchang 330032, Jiangxi, People's Republic of China
3. School of Materials Science and Engineering, Nanchang Hangkong University 3 , Nanchang 330063, People's Republic of China
4. School of Physics and Materials Science, Guangzhou University 4 , Guangzhou 510006, People's Republic of China