1. Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu610054, China
2. University of Michigan−Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai200240, China
3. Department of Physics, ETH Zurich, 8093Zurich, Switzerland
4. Department of Electrical and Computer Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, Florida32611, United States
5. College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing210023, China
6. Department of Electrical and Computer Engineering, University of Texas at El Paso, El Paso, Texas79968, United States
7. Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore560012, Karnataka, India
8. Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska68588, United States
9. Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai200050, China
10. ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona08860, Spain
11. School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
12. State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu610054, China