1. Institute of Physics and University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing 100190 China
2. Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences Beijing 100190 China
3. CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China
4. Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
5. Department of Physics and Astronomy and Department of Electrical and Computer Engineering Vanderbilt University Nashville TN 37235 USA