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