1. Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
2. Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya 463-8560, Japan
3. Department of Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan
4. Department of Chemistry, Saitama University, Saitama 338-8570, Japan
5. Device Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
6. Department of Materials Engineering, The University of Tokyo, Tokyo 113-8656, Japan