1. School of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
2. College of Physics and Electronic Engineering, Zhengzhou Normal University, Zhengzhou 450044, China
3. CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
4. Department of Physics, Shanghai University, Shanghai 200444, China