1. Research Center for Magnetic and Spintronic MaterialsNational Institute for Materials Science (NIMS) Tsukuba 305‐0047 Japan
2. Graduate School of Pure and Applied SciencesUniversity of Tsukuba Tsukuba 305‐8577 Japan
3. Electrical Engineering and ElectronicsKyoto Institute of Technology Kyoto 606‐8585 Japan
4. Center for Materials Research by Information IntegrationNational Institute for Materials Science (NIMS) Tsukuba 305‐0047 Japan
5. Center for Spintronics Research Network (CSRN)Graduate School of Engineering ScienceOsaka University Osaka 560‐8531 Japan