Monderkamp Paul A, Wittmann René, Cortes Louis B G, Aarts Dirk G A L, Smallenburg Frank, Löwen Hartmut
Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany.
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2021 Nov 5;127(19):198001. doi: 10.1103/PhysRevLett.127.198001.
We propose a general formalism to characterize orientational frustration of smectic liquid crystals in confinement by interpreting the emerging networks of grain boundaries as objects with a topological charge. In a formal idealization, this charge is distributed in pointlike units of quarter-integer magnitude, which we identify with tetratic disclinations located at the end points and nodes. This coexisting nematic and tetratic order is analyzed with the help of extensive Monte Carlo simulations for a broad range of two-dimensional confining geometries as well as colloidal experiments, showing how the observed defect networks can be universally reconstructed from simple building blocks. We further find that the curvature of the confining wall determines the anchoring behavior of grain boundaries, such that the number of nodes in the emerging networks and the location of their end points can be tuned by changing the number and smoothness of corners, respectively.
我们提出了一种通用形式主义，通过将新出现的晶界网络解释为具有拓扑电荷的物体，来表征受限近晶型液晶的取向受挫。在形式理想化中，这种电荷以四分之一整数大小的点状单位分布，我们将其与位于端点和节点处的四次位错相联系。借助广泛的蒙特卡罗模拟，针对广泛的二维受限几何形状以及胶体实验，对这种共存的向列相和四次序进行了分析，展示了如何从简单的构建块普遍重建观察到的缺陷网络。我们进一步发现，受限壁的曲率决定了晶界的锚定行为，使得通过分别改变角的数量和平滑度，可以调整新出现网络中的节点数量及其端点位置。
