1. a Liquid Crystal Nano‐system Project , SORST , Japan Science and Technology Agency , TRC 5‐9‐9 Tokodai, Tsukuba, Ibaraki 300‐2635, Japan
2. b Department of Materials Science and Technology , Faculty of Science and Technology , Hirosaki University , 3 Bunkyo‐cho, Hirosaki 036‐8561, Japan
3. c Liquid Crystal Materials Division , Dainippon Ink & Chemicals, Inc. , 4472‐1 Komuro, Ina‐machi, Kitaadachi‐gun, Saitama 362‐8577, Japan