1. Advanced Institute of Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
2. School of Advanced Materials and Nanotechnology, Xidian University, No. 2 South Taibai Road, Xi’an 710071, China
3. Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
4. Tohoku Fukushi University, Kunimi-ga-oka, Aoba-ku, Sendai 989-3201, Japan