1. National Laboratory of Solid State Microstructures, School of Physics & Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
2. Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
3. Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States