Fine structure of the topological defect cores studied for disclinations in lyotropic chromonic liquid crystals.
Fine structure of the topological defect cores studied for disclinations in lyotropic chromonic liquid crystals.
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DOI：
10.1038/ncomms14974
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发表时间：
2017-04-21
影响因子：
16.6
通讯作者：
Lavrentovich OD
中科院分区：
文献类型：
--
作者：
Zhou S;Shiyanovskii SV;Park HS;Lavrentovich OD
有序场奇点的详细结构是物理学各个领域的基本问题。在缺陷核处，变形是如此之强，以至于系统探索具有不同于未变形材料的对称性的状态。这些区域很难在实验上探索，因为它们的空间延伸非常小，在凝聚态物质中只有几个分子的长度。在这里，我们探讨的核心向错在所谓的色向列，延伸到宏观长度尺度可访问的光学表征。我们表明，振幅S和相位（导演）的顺序参数变化沿着径向和方位角方向，与经典模型中，S只与距离中心的变化，只依赖于方位角坐标。这种意想不到的核心结构是由一个强耦合的自由能的序参量的相位和振幅。拓扑缺陷在确定材料性能方面起着重要作用，而其核心区域由于强烈扭曲的结构而仍未被探索。Zhou等人利用有色液晶中的扩展芯区，并显示了径向和方位角依赖的指向矢和标量序参数。
The detailed structure of singularities of ordered field represents a fundamental problem in diverse areas of physics. At the defect cores, the deformations are so strong that the system explores states with symmetry different from that of an undistorted material. These regions are difficult to explore experimentally as their spatial extension is very small, a few molecular lengths in the condensed matter. Here we explore the cores of disclinations in the so-called chromonic nematics that extend over macroscopic length scales accessible for optical characterization. We demonstrate that the amplitude S and the phase (the director) of the order parameter vary along both the radial and azimuthal directions, in contrast to the classic models in which S varies only with the distance from the centre and depends only on the azimuthal coordinate. This unexpected core structure is explained by a strong coupling of the phase and amplitude of the order parameter in the free energy. Topological defects play important roles in determining material properties, whilst their core regions remain unexplored due to strongly distorted structures. Zhou et al. take advantage of extended core regions in a chromonic liquid crystal and show both a radial and azimuthal dependent director and scalar order parameter.