1. Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA
2. Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
3. Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
4. WPI Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
5. Center for Science and Innovation in Spintronics (CSIS), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
6. PRESTO, Japan Science and Technology Agency (JST), Kawaguchi 332-0012, Japan
7. Division for the Establishment of Frontier Sciences of Organization for Advanced Studies at Tohoku University, Tohoku University, Sendai 980-8577, Japan
8. National Institutes for Quantum Science and Technology, Takasaki 370-1207, Japan
9. Center for Innovative Integrated Electronic Systems (CIES), Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
10. Inamori Research Institute of Science (InaRIS), Kyoto 600-8411, Japan