1. Graduate School of Natural Science and Technology Kanazawa University Kanazawa 920-1192 Japan
2. Technical Engineering Division Arios Incorporated Akishima 196-0021 Japan
3. Arios Incorporated Akishima 196-0021 Japan
4. Advanced Power Electronics Research Center National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba 305-8568 Japan
5. Fraunhofer Institute for Applied Solid State Physics Applied Solid State Physics IAF Freiburg 79108 Germany
6. Nanomaterials Research Institute Kanazawa University Kanazawa 920-1192 Japan