1. Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology, Central 2 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
2. Quantum Materials and Applications Research Center, National Institutes for Quantum Science and Technology, Takasaki, Gunma 370-1292, Japan
3. Research Institute for Nanodevice, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima 739-8527, Japan