标题： 胶体螺旋在向列相液晶中 显示英文标题

标题： Colloidal spirals in nematic liquid crystals

摘要： 一项核心的实验努力在向列胶体研究中旨在探索粒子的几何形状以及围绕它们的向列取向变形和缺陷之间的相互作用如何能作为引导粒子自组装和控制粒子诱导缺陷结构的手段。 在这项工作中，我们设计、制造并分散低对称性的胶体粒子，在向列流体中具有螺旋形、双螺旋形和三螺旋形。 这些由改变其表面功能化以提供向列分子排列的切向或垂直边界条件所控制的螺旋形粒子，被发现会引发具有非手性或手性对称性的取向扭曲和缺陷配置。 胶体粒子在向列基质中也表现出稳定和亚稳的多重取向状态，其中大量的取向配置伴随着奇异和孤子非奇异拓扑缺陷，这可能导致不寻常的胶体自组装形式。 我们的发现直接证明了与固体微小包含物的低点群对称性相比，粒子生成的取向配置的对称性可以进一步降低，或者也可以不降低，这取决于所诱导缺陷的性质，同时满足拓扑约束。 我们表明，非手性胶体粒子可以引起弹性扭曲的手性对称性破缺，这是由所诱导的拓扑线缺陷和孤子的复杂三维缠绕驱动的。 显示英文摘要

摘要： One of the central experimental efforts in nematic colloids research aims to explore how the interplay between the geometry of particles along with the accompanying nematic director deformations and defects around them can provide a means of guiding particle self-assembly and controlling the structure of particle-induced defects. In this work, we design, fabricate, and disperse low-symmetry colloidal particles with shapes of spirals, double spirals, and triple spirals in a nematic fluid. These spiral-shaped particles, which are controlled by varying their surface functionalization to provide tangential or perpendicular boundary conditions of the nematic molecular alignment, are found inducing director distortions and defect configurations with non-chiral or chiral symmetry. Colloidal particles also exhibit both stable and metastable multiple orientational states in the nematic host, with a large number of director configurations featuring both singular and solitonic nonsingular topological defects accompanying them, which can result in unusual forms of colloidal self-assembly. Our findings directly demonstrate how the symmetry of particle-generated director configurations can be further lowered, or not, as compared to the low point group symmetry of solid micro-inclusions, depending on the nature of induced defects while satisfying topological constraints. We show that achiral colloidal particles can cause chiral symmetry breaking of elastic distortions, which is driven by complex three-dimensional winding of induced topological line defects and solitons.