Nanotechnology Research Center, Research Institute for Electronic Science, Hokkaido University, N21W10, Kita-ku, Sapporo, 001-0021, Japan, Frontier Research System, The Institute of Physical and Chemical Research (RIKEN Institute), 2-1, Hirosawa, Wako, Saitama, 351-0198, Japan, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 4-1-8, Hon-cho, Kawaguchi, Saitama, 332-0012, Japan, and Graduate School of Science, Hokkaido University, N10W8, Kita-ku,... (At 2006-10-14)