1. College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China
2. School of Physics and Engineering, Henan University of Science and Technology, Luoyang, 471023, China
3. School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
4. School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China