Dynamics of a ±1/2 defect pair in a confined geometry：A thin hybrid aligned nematic cell

• Published in: Chinese physics B Vol. 24; no. 2; pp. 330 - 335
• Main Author: 路丽霞 张志东
• Format: Journal Article
• Language: English
• Published: 01.02.2015
• Subjects: Alignment; Coalescing; Defects; Distortion; Dynamics; Eigenvalues; Exchange; Nematic; Walls; 交换结构; 几何形状; 单元格; 向列型; 平衡状态; 混合排列; 狭窄; 缺陷结构
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/24/2/026102

Confined geometry can change the defect structure and its properties.In this paper,we investigate numerically the dynamics of a dipole of ±1/2 parallel wedge disclination lines in a confined geometry：a thin hybrid aligned nematic（HAN） cell,based on the Landau-de Gennes theory.When the cell gap d is larger than a critical value of 12ξ（where ξis the characteristic length for order-parameter change）,the pair annihilates.A pure HAN configuration without defect is formed in an equilibrium state.In the confined geometry of d ≤ 12ξ,the diffusion process is discovered for the first time and an eigenvalue exchange configuration is formed in an equilibrium state.The eigenvalue exchange configuration is induced by different essential reasons.When 10ξ 〈 d ≤ 12ξ,the two defects coalesce and annihilate.The biaxial wall is created by the inhomogeneous distortion of the director,which results in the eigenvalue exchange configuration.When d≤ 10ξ,the defects do not collide and the eigenvalue exchange configuration originates from the biaxial seeds concentrated at the defects.