1. Research Center for Applied Quantum Physics, Hiroshima Institute of Technology, Hiroshima 731-5193, Japan
2. National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0003, Japan
3. Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0003, Japan
4. National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, U.S.A.
5. Condensed Molecular Materials Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
6. Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan