1. International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan
2. Faculty of Pure and Applied Physics, University of Tsukuba, Tsukuba, Japan
3. PRESTO, Japan Science and Technology Agency, Saitama, Japan
4. Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), Tsukuba, Japan
5. Department of Condensed Matter Physics, Graduate School of Science, Hokkaido University, Sapporo, Japan
6. Institute for Materials Research, Tohoku University, Sendai, Japan
7. Center for Spintronics Research Network, Tohoku University, Sendai, Japan