1. Superconducting Materials Laboratory, Graduate School of Science and Engineering, Shibaura Institute of Technology, 3-7-5, Toyosu,
Koto-ku, Tokyo 135-8548, Japan
2. Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Central 2, Umezono, Tsukuba, Ibaraki 305-8568, Japan