1. Department of Chemical and Biomolecular Engineering (BK-21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea, Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea, Material Research Laboratory, University of California Santa Barbara, Santa Barbara, California 93106, and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242