1. School of Engineering and the Center for Innovative Integrated Electronic Systems (CIES), Tohoku University, Sendai, Japan
2. Center for Innovative Integrated Electronic Systems (CIES), Tohoku University, Sendai, Japan
3. School of Engineering, the Center for Innovative Integrated Electronic Systems (CIES), the Research Institute of Electrical Communication (RIEC), and the Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai, Japan