1. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China.
2. School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
3. School of Physics and Electronics, Hunan University, Changsha 410082, P. R. China.
4. School of Physics, Peking University, Beijing 100871, P. R. China.
5. Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China.