1. Electronic Device Systems Business Group, Hitachi High-Technologies Corporation, 794 Higashitoyoi, Kudamatsu, Yamaguchi 744-0002, Japan
2. Department of Material Science and Engineering, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742
3. Department of Physics, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742