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论文类型：期刊论文

发表刊物：Light: Science & Applications

所属单位：光电学院，国家光电研究中心

刊物所在地：美国

学科门类：物理学

项目来源：自然科学基金

文献类型：J

卷号：176

期号：9

页面范围：1-10

关键字：无

DOI码：10.1038/s41377-020-00382-9

发表时间：2020-10-19

教研室：c716

摘要：It was recently demonstrated that the connectivities of bands emerging from zero frequency in dielectric photonic crystals are distinct from their electronic counterparts with the same space groups. We discover that in an AB-layer-stacked photonic crystal composed of anisotropic dielectrics, the unique photonic band connectivity leads to a new kind of symmetry-enforced triply degenerate points at the nexuses of two nodal rings and a Kramers-like nodal line. The emergence and intersection of the line nodes are guaranteed by a generalized 1/4-period screw rotation symmetry of Maxwell’s equations. The bands with a constant kz and iso-frequency surfaces near a nexus point both disperse as a spin-1 Dirac-like cone, giving rise to exotic transport features of light at the nexus point. We show that spin-1 conical diffraction occurs at the nexus point, which can be used to manipulate the charges of optical vortices. Our work reveals that Maxwell’s equations can have hidden symmetries induced by the fractional periodicity of the material tensor components and hence paves the way to finding novel topological nodal structures unique to photonic systems.

备注：无

发布期刊链接：https://doi.org/10.1038/s41377-020-00382-9