1. Institute for Integrated Cell-Material Sciences Kyoto University Institute for Advanced Study,Kyoto University Yoshida, Ushinomiya-cho Sakyo-ku Kyoto 606-8501 Japan
2. Laboratory of Theoretical and Computational Nanoscience National Center for Nanoscience and Technology of China Beijing 100190 China
3. RIKEN-JEOL Collaboration Center Yokohama Kanagawa 230-0045 Japan
4. JEOL Ltd., Musashino Akishima Tokyo 196-8558 Japan
5. State Key Laboratory of Multi-phase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Zhongguancun Beiertiao No. 1, Haidian Beijing 100190 China
6. Department of Physics Graduate School of Science Osaka Metropolitan University 599-8531 Osaka Japan