拓樸邊緣模態作為導波模態的魯棒性研究

In recent years, the study of topological materials has received much attention.When a material or structure with periodicity in space is used as a wavepropagation medium, the topological characteristics of its energy bands can beobtained by calculating the topological invariants such as Chen number, windingnumber, or Zak phase. According to the bulk-edge correspondence, when atopologically non-trivial material is connected to or surrounded by a topologicallytrivial material, a topological edge state will appear at the junction or the edge ofthe material. According to common opinion, this "topologically protected" edgestate has excellent anti-interference ability, and can bypass impurities ordislocations to guide waves without back scattering, so it is a robust waveguiding means.Based on the research of the past few years, we found that some topologicaledge states will disappear due to mismatched boundary conditions, even if thetopology of the bulk states is non-trivial. In this project, we will conduct in-depthresearch on the characteristics of topological edge states as guided wave modes.In addition to studying its anti-interference ability, we will also compare theadvantages and disadvantages of this type of wave guiding method with thetraditional photonic crystal waveguides. In the future, we hope to design betterwave guiding elements based on the research results of this project.