State transition at electrohydrodynamic convection of twisted nematic liquid crystals

作     者：Chul Gyu Jhun Gyu Jin Choi Dae Geon Ryu Jong-Hoon Huh Jin Seog Gwag 

作者机构：School of Display Engineering Hoseo University Asan-shi Chungnam 31499 Republic of Korea Department of Physics Yeungnam University 280 Daehak-Ro Gyeongsan 38541 Republic of Korea Department of Mechanical Information Science and Technology Faculty of Computer Science and Systems Engineering Kyushu Institute of Technology Iizuka Fukuoka 820–8502 Japan 

出 版 物：《Physical Review E》 (物理学评论E辑：统计、非线性和软体物理学)

年 卷 期：2018年第98卷第5期

页      面：052704-052704页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0702[理学-物理学] 

基　　金：National Research Foundation, NRF National Research Foundation, NRF Japan Society for the Promotion of Science, JSPS, (18K03464) Ministry of Science, ICT and Future Planning, MSIP, (2016R1D1A3B03932396) National Research Foundation of Korea, NRF 

主　　题：Convection Nematic liquid crystals Hydrodynamics 

摘      要：We study electrohydrodynamic convection (EHC) patterns in twisted nematic liquid crystal (TNCL) cells with an initial homeotropic alignment. In addition, we demonstrate switching characteristics due to the transition between the 90° and −90∘ twisted states. The pattern formations are similar to those obtained in a parallel-aligned nontwisted liquid crystal cell. Calculations of the free energy in an initially, homeotropically aligned TNLC in an electric field demonstrate that the energy barrier between the two states decreases with the increase of the electric field. The mutual transition is caused by the fluctuating flow at the dynamic scattering mode 2, where the energy barrier between the two states is reduced by applying a strong electric field. These properties may be employed for the development of a redirectable dynamic lenticular lens, as an extended version of the dynamic lenticular lens using EHC. The transition between the two states caused by EHC is reversible, and the convection roll pattern of the Williams domain rotates by 90° at each transition.