论文标题
在磁光介质中拓扑保护模式的离散近似
Discrete Approximation of Topologically Protected Modes in Magneto-Optical Media
论文作者
论文摘要
十年前，在计算和实验中研究了旋转型，磁化培养基的线性极化麦克斯韦方程中的拓扑保护波。本文为该系统开发了强大的紧密结合模型，以仔细使用Wannier功能表示。该模型为基础带结构提供了非常好的近似值。当在半无限条上求解时，它会产生指数局部的边缘模式，其相应的特征值跨越了频带差距。得出了一组耦合的微分方程，该方程使人们能够在单向上找到电磁场如何在无缺陷中进行反向散射。此外，离散模型预测具有非平凡的Chern号码的拓扑保护边缘模式，这些模式与直接模拟一致。
Topologically protected waves in the linearly polarized Maxwell's equations with gyrotropic, magneto-optic media were studied a decade ago both computationally and experimentally. This paper develops a robust tight-binding model for this system that makes careful use of Wannier function representations. The model provides very good approximations to the underlying band structure. When solved on a semi-infinite strip, it produces exponentially localized edge modes whose corresponding eigenvalues span the frequency band gaps. A set of coupled differential equations are derived which allows one to find how the electromagnetic field propagates unidirectionally, without backscatter from defects. Furthermore, the discrete model predicts topologically protected edge modes with nontrivial Chern number which are consistent with direct simulation.
