1. National Laboratory of Solid-State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
2. College of Physics, Nanjing University of Aeronautics and Astronautics and Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT, Nanjing 211106, China
3. Institute of Materials Engineering, Nanjing University, Nantong, Jiangsu 210093,China