1. International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
2. Research Institute for Science and Technology, Kogakuin University, Hachioji, Tokyo 192-0015, Japan
3. MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan