1. Graduate School of Engineering, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Miyagi 980-8579, Japan
2. Center for Innovative Integrated Electronics Systems (CIES), Tohoku University, 468-1 Aoba Aramaki, Aoba-ku Sendai, Miyagi 980-8572, Japan
3. Center for Spintronics Integrated Systems (CSIS), Tohoku University, 2-2-1 Katahira, Aoba-ku Sendai, Miyagi 980-8577, Japan
4. Center for Spintronics Research Network (CSRN), Tohoku University, 2-2-1 Katahira, Aoba-ku Sendai, Miyagi 980-8577, Japan