二维晶体中向错的电荷共轭对称性破缺

中文摘要 AI 辅助

向错是二维（2D）晶态膜中的基本拓扑缺陷，但其弹性质在很大程度上仍未被探索。我们采用原子级模拟，研究了自由-standing石墨烯（一种典型的二维晶体）中向错的能量学、形态和相互作用。我们发现，具有正拓扑电荷的向错遵循预期行为，而负向错则表现出能量随电荷的亚线性标度，以及与传统鞍形假设显著偏离的平衡形状。这种电荷共轭对称性的破缺导致了性质截然不同的相互作用：正向错相互排斥，而负向错则表现出强的长程吸引。研究表明，折叠膜中的自粘附会进一步放大这些趋势。我们的结果揭示了负曲率缺陷的根本不同的能量图景，为理解石墨烯及其他二维膜的稳定性、自折叠行为和缺陷驱动的形态提供了基础。

英文摘要

Disclinations are elementary topological defects in two-dimensional (2D) crystalline membranes, yet their elastic properties remain largely unexplored. Using atomistic simulations, we address the energetics, morphology, and interactions of disclinations in free-standing graphene, a prototypical 2D crystal. We find that while disclinations with positive topological charges follow an expected behavior, negative disclinations exhibit sublinear energy scaling with charge as well as equilibrium shape that deviates sharply from the conventional saddle ansatz. This breakdown of charge-conjugation symmetry leads to qualitatively distinct interactions: positive disclinations repel, whereas negative disclinations display a robust long-range attraction. These trends are shown to be further amplified by self-adhesion in folded membranes. Our results uncover a fundamentally different energetic landscape for negative curvature defects and provide a basis for understanding the stability, self-folding behavior, and defect-driven morphology of graphene and other 2D membranes.

发表机构

• Ecole Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）
• Radboud University（拉德堡德大学）
• Uppsala University（乌普萨拉大学）

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