Institution: | aResearch Center for Low Temperature and Materials Sciences, Kyoto University, Sakyo, 606-8502 Kyoto, Japan;bGraduate School of Science, Tohoku University, Aramaki-Aoba, Aoba, 980-8578 Sendai, Japan;cNTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan |