1. International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, People’s Republic of China
2. London Centre for Nanotechnology, UCL, London WC1H 0AH, United Kingdom; Department of Physics and Astronomy, University College London, London WC1E6BT, United Kingdom; and Department of Earth Sciences, University College London, London WC1E6BT, United Kingdom
3. Collaborative Innovation Center of Quantum Matter, Beijing 100871, People’s Republic of China