1. School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China
2. Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
3. Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
4. AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China