1. Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), Tsukuba, Japan
2. Department of Physics, Indian Institute of Technology Guwahati, Guwahati, India
3. Graduate School of Science and Technology, University of Tsukuba, Tsukuba, Japan
4. Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai, Japan