1. National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
2. School of Electronic Engineering & Intelligentization, Dongguan University of Technology, Dongguan 523808, Guangdong, China
3. Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States