[1] Dongguk Univ Seoul, Quantum Funct Semicond Res Ctr, Seoul 100715, South Korea
[2] Dongguk Univ Seoul, Dept Phys, Seoul 100715, South Korea
[3] Korea Inst Sci & Technol, Ctr Spintron Res, Seoul 136791, South Korea
[4] Korea Inst Sci & Technol, Spin Convergence Res Ctr, Seoul 136791, South Korea
[5] Korea Univ, KU KIST Grad Sch Converging Sci & Technol, Seoul 136701, South Korea
[6] Wuhan Univ, Dept Phys, Wuhan 430072, Peoples R China
[7] Korea Univ, Sch Elect Engn, Seoul 136713, South Korea
[8] Hanyang Univ, Dept Mat Sci & Engn, Seoul 133791, South Korea
[9] Hanyang Univ, Quantum Funct Spin Lab, Seoul 133791, South Korea
[10] Hanyang Univ, Dept Phys, Seoul 133791, South Korea