1. Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Central, 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
2. Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan
3. Technology Research Association for Single Wall Carbon Nanotubes (TASC), c/o National Institute of Advanced Industrial Science and Technology, Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan