1. Division
of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Hokkaido, Sapporo 060-8628, Japan
2. Department
of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Aichi, Nagoya 464-8603, Japan