Polarization-modulated smectic liquid crystal phases
Polarization-modulated smectic liquid crystal phases
复制标题
DOI：
10.1126/science.1084956
复制
发表时间：
2003-08-29
期刊：
影响因子：
56.9
通讯作者：
Clark, NA
中科院分区：
文献类型：
--
作者：
Coleman, DA;Fernsler, J;Clark, NA
任何具有空间均匀偏振场的极性有序材料都在内部受到挫折：对偏振的严格要求的局部偏好是不均匀的，即，局部呈花束状或“张开”。“然而，除非将适当的缺陷引入该领域，否则不可能在空间的任何地方实现首选标志的张开。典型地，在像铁电晶体或液晶的材料中，这样的缺陷不是热稳定的，使得局部偏好在全局上受到阻碍并且极化场保持均匀。在这里，我们报告了一类流体极性近晶液晶，其中局部splay盛行的形式，周期性的超分子尺度的偏振调制条纹耦合层波动波。极性域是局部手性的，并且被组织成交替手性和极性的模式。流体层的起伏使一个非凡的动物园。板和平面结构来识别这些相位。
Any polar-ordered material with a spatially uniform polarization field is internally frustrated: The symmetry-required local preference for polarization is to be nonuniform, i.e., to be locally bouquet-like or "splayed." However, it is impossible to achieve splay of a preferred sign everywhere in space unless appropriate defects are introduced into the field. Typically, in materials like ferroelectric crystals or liquid crystals, such defects are not thermally stable, so that the local preference is globally frustrated and the polarization field remains uniform. Here, we report a class of fluid polar smectic liquid crystals in which local splay prevails in the form of periodic supermolecular-scale polarization modulation stripes coupled to layer undulation waves. The polar domains are locally chiral, and organized into patterns of alternating handedness and polarity. The fluid-layer undulations enable an extraordinary menagerie of. lament and planar structures that identify such phases.