Theory of Liquid Crystals and Related Materials

9423114卢本斯基这个项目涉及与液晶有关的三个子项目的理论研究：准晶扭曲晶界C相、朗缪尔薄膜中液滴的形状以及液晶对光的多次散射。最近在实验上观察到孪晶晶界相。PI建议对此进行深入研究，包括发展近晶C相的规范理论，该理论将用于计算II型系统中的位错能，分析偶极相互作用，以及探索准晶锁定的起源。研究了最近观察到的Langmuir手性风轮液滴被有利于大周长的各向异性负线张力重现并捕获拓扑缺陷的可能性。我们将研究扩散波谱理论在向列型液晶中的推广，在向列型液晶中，介电常数的长程起伏在各向异性介质中产生多次散射。在这个项目中，卢本斯基将继续他对复杂流体的理论研究，如液晶。他被认为是这些材料理论的世界领先者。第一部分涉及对一种具有独特结构和对称性的相(最近在实验中发现)的研究，这可能被证明是重要的技术。第二部分，涉及分子膜液滴形状的研究，将有助于了解组成单分子层的分子之间的相互作用，这是物理学家和生物学家都非常感兴趣的话题。第三部分分析了一种相对较新的实验技术在液晶中的应用，这可能会为研究液晶提供一个重要的工具。值得注意的是，卢本斯基刚刚与查金合作编写了一本研究生级别的凝聚态物理新教科书，许多人认为这本教科书将取代目前被认为是这一领域标准的教科书。***

9423114 Lubensky This project involves theroetical investigations of three subprojects related to liquid crystals: the quasicrystalline twist-grain-boundary C phase, the shape of droplets in Langmuir films, and multiple scattering of light from liquid crystals. The twin-grain-boundary phase has recently been observed experimentally. The PI proposes to study this thoroughly, including the development of a guage theory for the Smectic-C phase that will be used to calculate dislocation energies in type II systems, an analysis of dipolar interactions, and a search for the origins of quasicrystalline lock-in. The possibility that chiral pinwheel droplets of Langmuir which have been observed recently are reproduced by effective anisotropic negative line tension favoring large perimeter and the capture of a topological defect will be investigated. The extension of diffusion-wave spectroscopy formalism to nematic liquid crystals in which multiple scattering in an anisotropic medium is produced by long-range fluctuations in the dielectric constant will be studied. %%% In this project Lubensky will continue his theoretical study of complex fluids, such as liquid crystals. He is considered a world leader in the theory of these materials. The first part involves the investigation of a phase (just recently discovered in experiments) of unique structure and symmetry which may prove to be technologically important. The second part, involving the study the shapes of droplets of molecular films, will help understand interactions within the molecules that make up monolayers, a topic of great interest to both physicists and biologists. The third part, analyzing the application of a relatively new experimental technique to liquid crystals, may provide an important tool for studying liquid crystals. It is worth noting that Lubensky has just finished his collaboration with Chaikin of a new textbook in graduate level condensed matter physics that many believe will replace the textbook currently considered the standard in this area. ***