Affiliation: | 1. Department of Applied Physics, Waseda University, 3‐4‐1 Okubo, Shinjuku‐ku, Tokyo 169‐0072, Japan;2. National Institute for Materials Science, 1‐1 Namiki, Tsukuba‐shi, Ibaraki 305‐0044, Japan;3. Fundamental Electronics Research Institute, Academic Frontier Promotion Center, Osaka Electro‐Communication University, 18‐8 Hatsu‐cho, Neyagawa, Osaka 572‐8530, Japan |