1. Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
2. Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
3. Department of Advanced Materials Science, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
4. Office of University Professor, The University of Tokyo, Kashiwa, Chiba 277-8568, Japan.
5. Material Innovation Research Center, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
6. Trans-scale Quantum Science Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.