1. Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical CommunicationTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
2. Advanced Institute for Materials ResearchTohoku University 2-1-1 Katahira, Aoba-ku, Sendai-shi Miyagi 980-8577 Japan
3. Department of Applied Chemistry and Life ScienceToyohashi University of Technology 1-1 Hibarigaoka, Tempaku-cho, Toyohashi Aichi 441-8580 Japan
4. Graduate School of Science and EngineeringSaitama University 255 Shimo-Okubo, Sakura-ku, Saitama-shi Saitama 338-8570 Japan
5. Kansei Fukushi Research InstituteTohoku Fukushi University 6-149-1 Kunimi-ga-oka, Aoba-ku, Sendai-shi Miyagi 989-3201 Japan