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向列顺序重建的最新进展

Recent advances on nematic order reconstruction
课程网址: http://videolectures.net/clc2010_barberi_ranor/  
主讲教师: Riccardo Barberi
开课单位: 卡拉布里亚大学
开课时间: 2010-08-05
课程语种: 英语
中文简介:
对Pi细胞(一种导向器旋转180°的夹层单元)的研究证明了在两种具有不同拓扑结构的纹理之间获得向列跃迁的可能性,例如在无扭曲状态和Pi扭曲状态之间。通过合适的电场或通过向列体中或靠近边界表面的微/纳米限制可以观察到快速的拓扑变化。事实上,强烈的挫败感,如在强烈的局部失真的情况下,可以在向列型脉冲阶段内引起瞬态和/或局部双轴状态,并且由此产生的向列动力学需要完整的Landau de Gennes Q张量描述。在这项工作中,我们提出Q张量数值模型能够详细描述向列顺序动力学,比较理论结果与实验。我们还将讨论靠近具有强或无限锚定条件的边界面的向列顺序重建可以提供相当于锚定断裂的过渡。
课程简介: Investigations on Pi-cell, a sandwich cell with the director rotating by 180°, are demonstrating the possibility to obtain nematic transitions between two textures with different topologies, for instance between an untwisted state and a Pi-twisted one. Fast topological changes can be observed by means of suitable electric fields or by micro/nano-confinement in the nematic bulk or close to a boundary surface. A strong frustration, in fact, as in the case of a strong local distortion, can induce transient and/or local biaxial states inside a nematic calamitic phase and the resultant nematic dynamics demands a full Landau-de Gennes Q-tensor description. In this work, we present Q-tensor numerical models capable to describe the nematic order dynamics in full details, comparing theoretical results with experiments. We will also discuss as nematic order reconstruction close to a boundary surface with strong or infinite anchoring conditions can provide transitions equivalent to anchoring breaking.
关 键 词: 向列顺序动力学; 向列顺序重建; 拓扑结构
课程来源: 视频讲座网
最后编审: 2019-03-01:cwx
阅读次数: 63