Li Huichang, Luo Chen, Zhang Tailin, Xu Jianwei, Zhou Xiang, Shen Yun, Deng Xiaohua
School of Physics and Materials Science, Nanchang University, Nanchang 330031, China.
Institute of Space Science and Technology, Nanchang University, Nanchang 330031, China.
Nanomaterials (Basel). 2022 Apr 28;12(9):1493. doi: 10.3390/nano12091493.
A valley-Hall-like photonic insulator based on C3v Kagome split-ring is proposed. Theoretical analysis and numerical calculations illustrate that C3v symmetry can be broken not only by global rotation α but also individual rotation θ of the split rings, providing topological phase transitions. Furthermore, refraction of the edge state from the interface into the background space at Zigzag termination is explored. It is shown that positive/negative refraction of the outgoing beam depends on the type of valley ( or K'), from which the edge state is projected. These results provide a new way to manipulate terahertz wave propagation and facilitate the potential applications in directional collimation, beam splitting, negative refraction image, etc.
提出了一种基于C3v Kagome开口环的类谷-霍尔光子绝缘体。理论分析和数值计算表明，C3v对称性不仅可以通过整体旋转α打破，还可以通过开口环的单独旋转θ打破，从而提供拓扑相变。此外，还研究了锯齿形端接处边缘态从界面折射到背景空间的情况。结果表明，出射光束的正/负折射取决于边缘态所投影的谷（或K'）的类型。这些结果为太赫兹波传播的操控提供了一种新方法，并促进了其在定向准直、光束分裂、负折射成像等方面的潜在应用。
