1. Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
2. Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
3. Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai 980-8577, Japan
4. Center for Spintronics Research Network (CSRN), Tohoku University, Sendai 980-8577, Japan
5. Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku Univeristy, Sendai 980-8577, Japan