1. Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Korea.
2. Ewha Womans University, Seoul 03760, Korea.
3. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
4. Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
5. Department of Physics, Ewha Womans University, Seoul 03760, Korea.
6. The Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan.
7. Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain.
8. Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain.
9. Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.
10. IBM Research Division, Almaden Research Center, San Jose, CA 95120, USA.