Higher-order topological states in photonic kagome crystals with long-range interactions
Higher-order topological states in photonic kagome crystals with long-range interactions
复制标题
长程相互作用Kagome光子晶体中的高阶拓扑态
DOI：
10.1038/s41566-019-0561-9
复制
发表时间：
2020-02-01
期刊：
影响因子：
35
通讯作者：
Khanikaev, Alexander B.
中科院分区：
文献类型：
--
作者：
Li, Mengyao;Zhirihin, Dmitry;Khanikaev, Alexander B.
光子拓扑绝缘体能够实现对缺陷和无序有弹性的拓扑边界模式，而不管制造精度如何。这个属性被称为拓扑保护。虽然最初仅限于比拓扑绝缘体低一个维度的模式，但最近发现的高阶拓扑绝缘体（HOTI）在扩展的维度范围内提供拓扑保护。在这里，我们介绍了一个光子HOTI与kagome晶格，表现出拓扑体极化，导致一维边缘状态的出现，以及高阶零维状态局限于角落的结构。有趣的是，除了由于最近邻相互作用的角态，我们发现了一类新的拓扑角态诱导的长程相互作用和特定的光子系统。我们的研究结果表明，光子HOTI具有比凝聚态更丰富的物理性质，为设计具有独特拓扑鲁棒性的新型设计者电磁态提供了机会。
Photonic topological insulators enable topological boundary modes that are resilient to defects and disorder, irrespective of manufacturing precision. This property is known as topological protection. Although originally limited to dimensionality of modes one lower than that of topological insulators, the recently discovered higher-order topological insulators (HOTIs) offer topological protection over an extended range of dimensionalities. Here, we introduce a photonic HOTI with kagome lattice that exhibits topological bulk polarization, leading to the emergence of one-dimensional edge states, as well as higher-order zero-dimensional states confined to the corners of the structure. Interestingly, in addition to the corner states due to nearest-neighbour interactions, we discover a new class of topological corner states induced by long-range interactions and specific to photonic systems. Our findings demonstrate that photonic HOTIs possess richer physics than their condensed-matter counterparts, offering opportunities for engineering novel designer electromagnetic states with unique topological robustness.One- and zero-dimensional optical states are revealed in photonic higher-order topological insulators.