1. Faculty of Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
2. Takasaki Advanced Radiation Research Institute, National Institute for Quantum and Radiological Science and Technology, Takasaki, Gunma 370-1292, Japan
3. Division of Electronics and Informatics, Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan
4. Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, Melbourne, VIC 3010, Australia
5. National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
6. Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, Shinjuku, Tokyo 169-0051, Japan
7. Research Center for Knowledge Communities, University of Tsukuba, Tsukuba, Ibaraki 305-8550, Japan