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

• 作者: 张志东 路丽霞
• 来源期刊: 中国物理B（英文版）
• 关键词: ±1/2 defect pair dynamics eigenvalue exchange configuration confined geometry
• 年，卷（期）: 2015,（2）
• 页码范围: 026102-1-026102-6
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/24/2/026102

摘要

Confined geometry can change defect structure and 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 Landau–de Gennes theory. When the cell gap d is larger than a critical value of 12ξ (whereξ is the characteristic length for order-parameter change), the pair annihilates. A pure HAN configuration without defect is formed in an equi-librium 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 inhomoge-neous 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.