Topological Refraction in Kagome Split-Ring Photonic Insulators

Nanomaterials

Jianwei Xu¹  Huichang Li¹  Tailin Zhang¹  Xiang Zhou¹  Yun Shen¹  Chen Luo¹  Xiaohua Deng¹ 

[1] School of Physics and Materials Science, Nanchang University, Nanchang 330031, China;

关键词: topological phase transition;    valley-Hall-like topology;    edge states;    topological refraction;   

DOI  :  10.3390/nano12091493

来源: DOAJ

【 摘 要 】

A valley-Hall-like photonic insulator based on $C_{3v}$ Kagome split-ring is proposed. Theoretical analysis and numerical calculations illustrate that $C_{3v}$ symmetry can be broken not only by global rotation $\alpha$ but also individual rotation $\theta$ 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 (K or $K^{\prime }$), 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.

【 授权许可】

Unknown