1. Aida Nanospace Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, National Museum of Emerging Science and Innovation, 2-41 Aomi, Koto-ku, Tokyo 135-0064, Japan.
2. Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561, Japan.
3. Advanced Research Laboratory, Hitachi Ltd., Hatoyama, Saitama 350-0395, Japan.
4. Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central-6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.