1. Department of Electrical Engineering and Information Systems School of Engineering The University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113–8656 Japan
2. Center for Emergent Matter Science RIKEN 2‐1 Hirosawa, Wako Saitama 351–0198 Japan
3. Thin‐Film Device Laboratory RIKEN 2‐1 Hirosawa, Wako Saitama 351–0198 Japan
4. Institute of Engineering Innovation Graduate School of Engineering The University of Tokyo Bunkyo‐ku Tokyo 113–8656 Japan