Second-order photonic topological insulator with corner states

作者：Biye Xie, Hongfei Wang, Hai‐Xiao Wang, Xue-Yi Zhu, Jian‐Hua Jiang, Ming‐Hui Lu, Yan‐Feng Chen · 发表于：Physical review. B./Physical review. B · 年份：2018 · DOI：10.1103/physrevb.98.205147 · 被引用次数：507 · 研究领域：Topological Materials and Phenomena、Graphene research and applications、Algebraic structures and combinatorial models

Higher-order topological insulators (HOTIs) which go beyond the description of conventional bulk-boundary correspondence, broaden the understanding of topological insulating phases. Being mainly focused on electronic materials, HOTIs have not yet been found in photonic crystals. Here, we propose a type of two-dimensional second-order photonic crystals with zero-dimensional corner states and one-dimensional boundary states for optical frequencies. All of these states are topologically nontrivial and can be understood based on the theory of topological polarization. Moreover, by tuning the easily fabricated structure of the photonic crystals, different topological phases can be realized straightforwardly. Our study can be generalized to higher dimensions and provides a platform for higher-order photonic topological insulators and semimetals.