1. Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing100049, China
2. Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Division of Advanced Materials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123China
3. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing100049, China
4. Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore117551
5. Kavli Institute for Theoretical Sciences, and CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing100190, China