1. National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University 1 , Nanjing 210093, China
2. School of Physics, Nanjing University 2 , Nanjing 210093, China
3. School of Materials Science and Intelligent Engineering, Nanjing University 3 , Suzhou 215163, China
4. Atom Manufacturing Institute 4 , Nanjing 211806, China