标题： 几何受限向列相液晶中的多稳态极性纹理 显示英文标题

标题： Multistable polar textures in geometrically frustrated nematic liquid crystals

摘要： 利用多个外部场操控极性实体的能力，为自旋系统、光子学、超材料和软物质中的新兴功能和新应用开辟了令人兴奋的可能性。 液晶（LCs）表现出晶体结构和液体流动性，是操控具有极性分子有序相的有前途的平台，特别是铁电相。 然而，使用棒状LC分子实现极性对称性具有挑战性，因为它们主要形成非极性向列相。 我们报告了一种方法，其中利用向列LC的几何晶格限制，在介观超材料的尺度上诱导平面极性有序。 我们将向列LC限制在微柱阵列中，形成具有与不混溶流体接触的自由顶部界面的弹性偶极子拓扑缺陷-微柱对。 所产生的偶极子晶格配置可以通过流动顶部流体进行流变编程，并且即使在流动停止后也能保持，这种现象归因于偶极子的取向多稳态。 这种多记忆效应使得方向信息的编码和重新配置成为可能。 总体而言，这项研究建立了在受限和剪切流下拓扑偶极子的基础理解，实现了流动剖面的检测、跟踪和记录，并为软物质物理和响应性材料的未来发展铺平了道路。 显示英文摘要

摘要： The ability to manipulate polar entities with multiple external fields opens exciting possibilities for emerging functionalities and novel applications in spin systems, photonics, metamaterials, and soft matter. Liquid crystals (LCs), exhibiting both a crystalline structure and liquid fluidity, represent a promising platform for manipulating phases with polar molecular order, notably ferroelectric ones. However, achieving a polar symmetry is challenging with rod-shaped LC molecules, which form predominantly apolar nematic phases. We report an approach in which a geometric lattice confinement of nematic LCs is used to induce planar polar order on the scale of a mesoscopic metamaterial. We confine the nematic LC in a micropillar array, forming topological defect-pillar pairs of elastic dipoles with a free top interface in contact with an immiscible fluid. The resulting dipole lattice configurations can be programmed rheologically by flowing the top fluid and maintained even after flow cessation, a phenomenon attributed to orientational multistability of the dipoles. This multi-memory effect enables the encoding and reconfiguration of directional information. Overall, this research establishes a foundational understanding of topological dipoles under confinement and shear flow, enabling the detection, tracking, and recording of flow profiles and paving the way for future advances in soft matter physics and stimuli-responsive materials.