Defect Interactions in Anisotropic Two-Dimensional Fluids.
Defect Interactions in Anisotropic Two-Dimensional Fluids.
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各向异性二维流体中的缺陷相互作用
DOI：
10.1103/physrevlett.117.157801
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发表时间：
2016
影响因子：
8.6
通讯作者：
K. Harth
中科院分区：
文献类型：
--
作者：
R. Stannarius;K. Harth
液晶中的向错与各种物理系统中的缺陷结构有着惊人的相似之处，它们直接的光学可观测性使它们成为研究缺陷相互作用基本性质的极好模型。我们采用自由悬浮的近晶膜，其表现为准二维极性向列相。介绍了一种在局域斑中捕获高强度向错的方法。这些向错被释放在一个受控的方式，和运动的相互排斥的拓扑电荷与电子的定量研究。我们证明，经典模型，采用弹性一常数近似，不能正确地描述他们的动态。在实际液晶中，即使展曲和弯曲常数之间的微小差异也会导致选择纯展曲或纯弯曲缺陷。对于那些，模型只能在非常特殊的配置中工作。一般来说，涉及额外的指向矢壁，其显著地增强排斥相互作用。
Disclinations in liquid crystals bear striking analogies to defect structures in a wide variety of physical systems, and their straightforward optical observability makes them excellent models to study fundamental properties of defect interactions. We employ freely suspended smectic-films, which behave as quasi-two-dimensional polar nematics. A procedure to capture high-strength disclinations in localized spots is introduced. These disclinations are released in a controlled way, and the motion of the mutually repelling topological charges with strengthis studied quantitatively. We demonstrate that the classical models, which employ elastic one-constant approximation, fail to describe their dynamics correctly. In realistic liquid crystals, even small differences between splay and bend constants lead to the selection of pure splay or pure benddefects. For those, the models work only in very special configurations. In general, additional director walls are involved which reinforce the repulsive interactions substantially.