发表机构
South China University of Technology; Singapore University of Technology and Design; Peking University（华南理工大学; 新加坡科技设计大学; 北京大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在无全局对称性的光子晶体中，通过局域调控角几何，实验观测到源于狄拉克点的抗无序鲁棒角态，拓展了光局域化的实现途径。
AI 中文摘要
鲁棒角态近年来在光子系统中受到了大量关注，它们通常在二阶拓扑绝缘体中实现，包括收缩-扩展晶格和呼吸 Kagome 晶格，全局对称性对其形成至关重要。然而，这种对对称性的依赖会使这些态对结构无序高度敏感。本文提出并实验演示了一类无需全局对称性和非平凡拓扑的光子晶体鲁棒角态。通过对原本拓扑平凡结构的角几何进行局域调控，我们创建了在位置和半径无序下均保持稳定的强局域化模式。这些态并非偶然出现，而是源于体带结构中的一对狄拉克点。几何调谐将连接狄拉克点的平带边缘态移至原本平凡的带隙中，从而诱导出强局域化角态。我们的发现揭示了一类此前被忽视的与对称性无关、抗无序的角态，将鲁棒局域化扩展至传统拓扑保护之外，并为全介质光子系统中的光局域化提供了途径。
英文摘要
Robust corner states have attracted considerable attention in recent years, particularly in photonic systems. They are typically realized in second-order topological insulators, including shrunken-expanded lattices and breathing Kagome lattices, where global symmetries are essential in their formation. This reliance on symmetry, however, can make these states highly sensitive to structural disorder. Here, we propose and experimentally demonstrate a class of robust corner states in photonic crystals that require neither global symmetry nor nontrivial topology. By locally tailoring the corner geometry of an otherwise topologically trivial structure, we create strongly localized modes that remain stable under both position and radius disorder. These states are not accidental; rather they originate from a pair of Dirac points in the bulk band structure. Geometric tuning shifts the flatband edge states connecting the Dirac points into an otherwise trivial bandgap, thereby inducing strongly localized corner states. Our findings uncover a previously overlooked class of symmetry-independent, disorder-resilient corner states, extend robust localization beyond conventional topological protection, and provide a route toward light localization in all-dielectric photonic systems.
Comments18 pages, 4 figures
