1. Material Design and Characterization Laboratory, Institute for Solid State Physics, the University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8666
2. Mega Gauss Laboratory, Institute for Solid State Physics, the University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8666
3. Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502