1. Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Sapporo 060-0813, Japan
2. Shibaura Institute of Technology, Tokyo 135-8548, Japan
3. International Center for Materials Nanoarchitectonics, National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
4. Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University, Nagoya 464-8601, Japan