1. Hefei National Laboratory
for Physical Sciences at the Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026, China
2. Key Laboratory of Polar Materials and Devices,
Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241, China
3. Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, United States
4. Department
of Physics, Pennsylvania State University, University Park 16802, United States
5. Collaborative Innovation Center of Extreme
Optics, Shanxi University, Shanxi 030006, China
6. Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China