1. Research Center for Condensed Matter Physics, Department of Civil Engineering and Urban Design, Hiroshima Institute of Technology, Hiroshima 731-5193, Japan
2. Department of Electrical and Electronic Engineering, Okayama University, Okayama 700-8530, Japan
3. Department of Physics, Kumamoto University, Kumamoto 860-8555 Japan
4. Collaboratory for Advanced Computing and Simulations, Department of Computer Science, Department of Physics & Astronomy, Department of Chemical Engineering & Materials Science, Department of Biological Sciences, University of Southern California, CA90089-024, U.S.A.