1. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
2. The Instruments Center for Physical Science, University of Science and Technology of China, Hefei 230026, China
3. Yongjiang Laboratory, Ningbo 315202, China
4. Department of Physics & Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
5. School of Physical Science and Technology, Ningbo University, Ningbo 315211, China