1. Department of Physics
and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
2. Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
3. Shandong Institute of Aerospace Electronics Technology, Yantai 264670, China
4. Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China
5. Department of Electronics
and Materials Science, Graduate School of Integrated Science and Technology, Shizuoka University, Hamamatsu 432-8561, Japan