1. Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China
2. School of Physical Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
3. Jiangxi Institute of Rare Earths, Chinese Academy of Sciences, Ganzhou 341000, China
4. CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
5. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
6. Key Laboratory for Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China