Affiliation: | (1) Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon, 305-701, South Korea;(2) Department of Physics, Kwangwoon University, 447-1 Wolgye-dong, Nowon-ku, Seoul, 139-701, South Korea;(3) Department of Physics, Yonsei University, Seoul, 120-749, South Korea |