1. International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
2. Advanced Materials R&D Laboratories, Sumitomo Electric Industries, Ltd., 1-1-1 Koyakita, Itami, Hyogo 664-0016, Japan
3. MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan