1. Center for Spintronics Research Network (CSRN), The University of Tokyo 1 , 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
2. Department of Electrical Engineering and Information Systems, The University of Tokyo 2 , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
3. Institute for Chemical Research, Kyoto University 3 , Gokasho, Uji, Kyoto 611-0011, Japan
4. Center for Science and Innovation in Spintronics (CSIS), Tohoku University 4 , 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
5. Center for Spintronics Research Network (CSRN), Osaka University 5 , 1-3, Machikaneyama, Toyonaka, Osaka 560-8531, Japan
6. National Institute of Advanced Industrial Science and Technology (AIST) 6 , 1-1-1 Umezono, Tsukuba, Ibaraki 305-8560, Japan
7. Graduate School of Engineering, Osaka University 7 , 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
8. Institute for Nano Quantum Information Electronics (NanoQuine), The University of Tokyo 8 , 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan