Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
Phys Rev E. 2019 Nov;100(5-1):052702. doi: 10.1103/PhysRevE.100.052702.
We present a Monte Carlo simulation study of chiral nematic liquid crystals confined in torus-shaped and cylindrical cavities. For an achiral nematic with planar degenerate anchoring confined to a toroidal or cylindrical cavity, the ground state is defect free, with an untwisted director field. As chirality is introduced, the ground state remains defect free but the director field becomes twisted within the cavity. For homeotropic anchoring, the ground state for an achiral nematic within a toroidal cavity consists of two disclination rings, one large and one small, that follow the major circumference of the torus. As chirality is introduced and increased, this ground state becomes unstable with respect to twisted configurations. The closed nature of the toroidal cavity requires that only a half integer number of twists can be formed and this leads to the ground state being either a single disclination line that encircles the torus twice or a pair of intertwined disclination rings forming stable, knotted defect structures.
我们提出了一个关于手性向列液晶在环形容器和圆柱形容器中受限的蒙特卡罗模拟研究。对于具有平面简并锚定的各向同性向列液晶被限制在环形容器或圆柱形容器中，基态是无缺陷的，具有未扭曲的指向矢场。当引入手性时，基态仍然无缺陷，但指向矢场在腔体内变得扭曲。对于垂直锚定，各向同性向列液晶在环形容器中的基态由两个沿着环的主要周长的环形双折射线组成，一个大一个小。当引入并增加手性时，这个基态相对于扭曲构型变得不稳定。环形容器的封闭性质要求只能形成半整数个扭曲，这导致基态要么是一个环绕环两次的单一直指向矢线，要么是一对相互缠绕的环形双折射线，形成稳定的、打结的缺陷结构。
