1. Department of Materials Science and Engineering, and Research Center for Neuromorphic AI Hardware, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan
2. Department of Materials Science, Osaka Prefecture University, Osaka, Japan
3. Department of Physics, Okayama University, Okayama, Japan
4. Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo, Hyogo, Japan
5. The Ultramicroscopy Research Center, Kyushu University, Fukuoka, Fukuoka, Japan
6. The Ultramicroscopy Research Center and Department of Applied Quantum, Physics and Nuclear Engineering, Kyushu University, Fukuoka, Fukuoka, Japan