椭球上六方与四方晶格共存中的缺陷组织
Defect Organization in Coexisting Hexagonal and Square Lattices on Ellipsoids
- Nankai University（南开大学）
- University of Waterloo（滑铁卢大学）
- The Hong Kong University of Science and Technology（香港科技大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过模拟退火朗之万动力学，探究椭球上六方与四方晶格共存时曲率对缺陷组织的调控，发现非均匀曲率可通过分配拓扑电荷和缺陷连通性来设计多样缺陷图案。
AI中文摘要：
曲率和拓扑共同组织二维晶体中的缺陷，但当竞争性的晶格对称性与空间变化的曲率共存时，它们的联合作用仍未解决。我们使用模拟退火朗之万动力学研究在长椭球和扁椭球上形成共存六方（Hex）和四方（Sq）晶格的赫兹粒子。绘制约化密度和纵横比揭示了在Hex主导和Sq主导背景中一系列广泛的疤痕和基于畴的形态。纬度分辨比较表明，在弱变形下，高斯曲率将缺陷偏向其最大值。然而，强长椭球形状将高曲率限制在无法独立容纳所有缺陷图案的小极帽中。缺陷随后向较低曲率纬度扩散，以缓解缺陷拥挤和弹性排斥。在Hex主导区域，这种竞争驱动具有中和角接触的顶点接触畴，补偿性正缺陷位于极点之外。Sq主导区域具有富Hex三角形畴、桥接态以及同样由曲率各向异性重组的线性或开放疤痕。在扁椭球上，延伸的赤道高曲率带允许缺陷在方位角上分离，同时保持曲率局域化。这项工作阐明，非均匀曲率可以通过选择拓扑电荷的空间分布和有限缺陷图案的连通性来工程化丰富的缺陷图案。
英文摘要：
Curvature and topology jointly organize defects in two-dimensional crystals, but their combined role remains unresolved when competing lattice symmetries coexist with spatially varying curvature. We use simulated-annealing Langevin dynamics to study Hertzian particles forming coexisting hexagonal (Hex) and square (Sq) lattices on prolate and oblate ellipsoids. Mapping reduced density and aspect ratio reveals a broad sequence of scar and domain-based morphologies in both Hex-dominant and Sq-dominant backgrounds. Latitude-resolved comparisons show that Gaussian curvature biases defects toward its maxima under weak deformation. Strong prolateness, however, confines high curvature to small polar caps that cannot independently accommodate all defect motifs. Defects then spread toward lower-curvature latitudes to relieve defect crowding and elastic repulsion. In the Hex-dominant regime, this competition drives vertex-contacted domains with neutralized corner contacts, and compensating positive defects locate away from the poles. The Sq-dominant regime features Hex-rich triangular domains, bridged states, and linear or open scars similarly reorganized by curvature anisotropy. On oblate ellipsoids, the extended equatorial high-curvature belt allows defects to separate azimuthally while remaining curvature-localized. This work elucidates that nonuniform curvature can engineer rich defect patterns by selecting the spatial distribution of topological charge and the connectivity of finite defect motifs.
