1. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, P. R. China
2. Centre for Programmed Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
3. NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
4. Collaborative Innovation Center of Quantum Matter, Beijing 100871, P. R. China