1. Graduate School of Engineering, Gunma University, Kiryu, Gunma 376-8515
2. Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801
3. Graduate School of Science, University of Hyogo, Ako, Hyogo 678-1297
4. Graduate School of Science, Tohoku University, Sendai 980-8578
5. Institute for Materials Research, Tohoku University, Sendai 980-8577
6. Department of Applied Physics, University of Tokyo, Tokyo 113-8656
7. Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562
8. Multiferroics Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012
9. Cross-Correlated Materials Research Group, RIKEN, Wako, Saitama 351-0198