1. School of Energy and Mechanical Engineering, Energy Materials Computing Center, Jiangxi University of Science and Technology, Nanchang330013, China
2. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai200433, P. R. China
3. School of Sciences, Shaoyang University, Shaoyang422001, China
4. Department of Physics and Key Laboratory for Low-Dimensional Structures and Quantum Manipulation (Ministry of Education), Hunan Normal University, Changsha410081, China
5. Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, Central South University, Changsha410083, China