1. Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi 441-8580, Japan
2. Murata Manufacturing Co., Ltd., Kyoto 617-8555, Japan
3. Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119992, Russia
4. Department of Physics, Keio University, Yokohama 223-8522, Japan
5. JST-PRESTO, Kawaguchi, Saitama 332-0012, Japan
6. Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA