ABSTRACT Using the perturbation theory (PT), reflected field both in specular and non specular directions from a slab made of topological insulator (TI) material with rough interface is studied. The specular reflections are described by zeroth order terms of the perturbation series while non specular reflections are associated with higher order terms. To describe the surface states on the TI, γ-model characterized by the surface admittance is utilized. It is observed that the co-polarized specular reflection increases for large values of surface admittance which results in vanishing transmission. The main objective is to pronounce distinctions between the results for a dielectric slab and TI slab. It is observed that the co polarized diffraction efficiency of the sinusoidal grating is enhanced for p-polarization as the surface admittance increases. Moreover, the scattering behavior of the TI slab with Gaussian rough interface as a function of surface admittance differs significantly from that of the dielectric slab.

中文翻译：

---

表面状态对由具有粗糙界面的拓扑绝缘体材料制成的平板散射的影响

摘要 使用微扰理论 (PT)，研究了由具有粗糙界面的拓扑绝缘体 (TI) 材料制成的平板在镜面和非镜面方向上的反射场。镜面反射由扰动序列的零阶项描述，而非镜面反射与更高阶项相关联。为了描述 TI 上的表面状态，使用了以表面导纳为特征的 γ 模型。可以观察到，对于大的表面导纳值，共偏振镜面反射会增加，这导致透射消失。主要目的是区分电介质板和 TI 板的结果。观察到随着表面导纳的增加，正弦光栅的共偏振衍射效率对于 p 偏振增强。