1. Thin‐Film Device LaboratoryRIKEN 2‐1 Hirosawa Wako Saitama 351‐0198 Japan
2. Electrical and Electronic Engineering and Information SystemsThe University of Tokyo 7‐3‐1 Bunkyo‐ku Tokyo 113‐8656 Japan
3. Center for Emergent Matter ScienceRIKEN 2‐1 Hirosawa Wako Saitama 351‐0198 Japan
4. College of Materials and Environmental EngineeringHangzhou Dianzi University Hangzhou 310‐018 P. R. China