In this paper, a hybrid topological material with hexagonal lattice arrangement is proposed, consisting of six metal cylindrical resonators and a dielectric slab. As a unit cell, the six metal cylindrical resonators satisfying the C₆ symmetry are selected, and the cylindrical resonators are inserted in the dielectric slab. It is demonstrated that a double Dirac cone is created at the Γ point in the proposed topological material. Since the topological effects of the proposed system can be invoked merely by varying the geometric parameters of the unit cell, two band gaps with different topological characteristics can be easily achieved. It is further demonstrated that the topologically protected edge states can be obtained by connecting the two types of lattices with different topological characteristics. Finally, we implement a sharp bend waveguide by using these two types of the topological lattices. It is demonstrated that electromagnetic waves can propagate robustly along the sharp bend interface.

本文提出了一种具有六边形格子排列的混合拓扑材料，它由六个金属圆柱谐振器和一个介电平板组成。作为一个单元，六个金属圆柱谐振器满足C₆选择对称性，然后将圆柱谐振器插入电介质平板中。结果表明，在Γ点在建议的拓扑材料中。由于仅通过改变晶胞的几何参数就可以调用所提出系统的拓扑效应，因此可以容易地获得具有不同拓扑特性的两个带隙。进一步证明，可以通过连接具有不同拓扑特征的两种类型的晶格来获得拓扑保护边缘状态。最后，我们通过使用这两种类型的拓扑格来实现尖锐的弯曲波导。事实证明，电磁波可以沿急弯界面牢固传播。