1. Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Japan
2. National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
3. Institute for Materials Research, Tohoku University, Sendai, Japan
4. Center for Spintronics Research Network, Tohoku University, Sendai, Japan
5. Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan