1. Physics Department, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures [Ministry of Education (MOE)], Fudan University, Shanghai 200433, China.
2. Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.
3. Key Laboratory of Polar Materials and Devices (MOE), East China Normal University, Shanghai 200241, China.
4. Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China.
5. Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
6. Physics Department, University of California, Berkeley, Berkeley, CA 94720, USA.