1. Department of Physics, Faculty of Science, Chulalongkorn
University, Bangkok 10330, Thailand, Condensed Matter Theory Group,
Department of Physics and Materials Science, Uppsala University, Box
530, SE-751 21 Uppsala, Sweden, Applied Materials Physics, Department
of Materials and Engineering, Royal Institute of Technology (KTH),
S-100 44 Stockholm, Sweden, and Department of Chemistry, Faculty of
Science, Chulalongkorn University, Bangkok 10330 Thailand