1. Department of PhysicsTohoku University Aoba, Sendai 980–8578 Japan
2. Department of PhysicsFaculty of Science and TechnologyTokyo University of Science Noda 278–8510 Japan
3. Frontier Research Center for Applied Atomic SciencesIbaraki University Tokai Ibaraki 319–1106 Japan
4. Institute for Materials ResearchTohoku University Aoba, Sendai 980–8577 Japan
5. Dr. Y. Ishikawa, Prof. T. KamiyamaInstitute of Materials Structure Science KEK, Tokai Ibaraki 319–1106 Japan
6. Sokendai (The Graduate University for Advanced Studies) Tokai Ibaraki 319–1106 Japan
7. Dr. S. Ohira‐Kawamura, Dr. M. KofuJ‐PARC CenterJapan Atomic Energy Agency Tokai Ibaraki 319–1195 Japan