1. RIKEN Center for Emergent Matter Science (CEMS); Wako 351-0198 Japan
2. Department of Advanced Materials Science; University of Tokyo; Kashiwa 277-8561 Japan
3. Research and Development Headquarters; ROHM Co., Ltd.; Kyoto 615-8585 Japan
4. Department of Applied Physics and Quantum Phase Electronics Center (QPEC); University of Tokyo; Tokyo 113-8656 Japan