1. Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology, Umezono 1 , Tsukuba, Ibaraki 305-8568, Japan
2. Nanomaterials Research Institute, Kanazawa University 2 , Kanazawa, Ishikawa 920-1192, Japan
3. Department of Electrical and Electronics Engineering, School of Engineering, Tokyo Institute of Technology, Ookayama 3 , Meguro, Tokyo 152-8552, Japan
4. Institute for Chemical Research, Kyoto University 4 , Gokasho, Uji, Kyoto 611-0011, Japan
5. Center for Spintronics Research Network, Institute for Chemical Research, Kyoto University 5 , Gokasho, Uji, Kyoto 611-0011, Japan