1. Institute of Fundamental and Frontier Science, University of Electronic Science and Technology of China, Chengdu 610054, China
2. College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, China
3. School of Physics, Nankai University, Tianjin 300071, China
4. Department of Physics & Astronomy, Ohio University, Athens, Ohio 45701, United States
5. Department of Mechanical Engineering, University of Houston, Houston, Texas 77204-4006, United States
6. School of Physics and Technology, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
7. Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, China