Prewavy instability-originated dielectric chevrons of electroconvection in nematic liquid crystals
Prewavy instability-originated dielectric chevrons of electroconvection in nematic liquid crystals
复制标题
向列液晶中电对流的前波不稳定性引发的介电 V 形
DOI：
10.1103/physreve.102.042704
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发表时间：
2020
影响因子：
2.4
通讯作者：
Huh Jong-Hoon
中科院分区：
文献类型：
--
作者：
Shiomi Masato;Choi E-Joon;Huh Jong-Hoon
本文报道了在交流驱动下，在高频介电状态下观察到的双相液晶（NLC）电对流中斑图的形成和演化。结果表明，波前不稳定性是形成和演化的关键。具体来说，在扭曲排列的NLC单元中，我们观察到一种独特的图案，该图案与通常在传统平面排列图案中观察到的电介质V形（DCV）相当。它被确定为一个组合的PW模式与介质正常卷（DNR）。此外，功率指数由PW、DNR和DCV的频率依赖性阈值确定。通过考虑PW的出现和不同的功率指标，提出了DCV的模式演化方案，可以很好地解释以前的实验结果。具体而言，PW起源的DCV2明显不同于缺陷介导的DCV1，这被称为典型的模式进化。
This paper reports the pattern formation and evolution in a high-frequency dielectric regime observed in the AC-driven electroconvection of nematic liquid crystals (NLCs). It is determined that prewavy (PW) instability is essential for the formation and evolution. Specifically, in a twisted-aligned NLC cell, we observe a unique pattern that is comparable to the dielectric chevrons (DCVs) typically observed in a conventional planarly aligned pattern. It is determined to be a combined PW pattern with dielectric normal rolls (DNRs). Moreover, the power indicesare determined from the frequency-dependent thresholdsof PW, DNR, and DCV. By taking into account the appearance of PW and the different power indices, the pattern evolution scenarios for DCV are proposed, which can well explain the previous experimental results. Specifically, the PW-originated DCV2 clearly differs from the defect-mediated DCV1, which is known as a typical pattern evolution.