We perform mathematical modeling of diffraction of plane electromagnetic waves by multilayer metasurfaces comprised by elements of graphene nanoribbons. The modeling is based on solving the three-dimensional boundary value diffraction problem by three methods, specifically, those of self-contained units with Floquet channels, the volume integro-differential equation, and approximate boundary conditions. The coefficients of reflection, transmission, and absorption of s- and p-polarized waves by metasurfaces made of elements of rectangular graphene nanoribbons are calculated as functions of the frequency and the incidence angle for various values of the chemical potential with allowance for the geometric and dimensional effects in the terahertz frequency band. It is shown that at the resonant frequencies of the surface plasmon polariton, multilayer metasurfaces comprised by two graphene strips in an elementary cell on substrates, which contain layers of a dielectric and graphene, are electrically controlled efficient wideband terahertz absorbers and polarizers in the reflection regime that are insensitive to incidence angles.

中文翻译：

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太赫兹频带中多层石墨烯超表面对电磁波的衍射

我们通过由石墨烯纳米带元素组成的多层超表面对平面电磁波的衍射进行数学建模。该建模基于通过三种方法解决三维边界值衍射问题，具体而言，具有 Floquet 通道的独立单元、体积积分微分方程和近似边界条件。由矩形石墨烯纳米带元素制成的超表面对 s 和 p 偏振波的反射、透射和吸收系数计算为频率和入射角的函数，化学势的各种值都考虑了几何和太赫兹频段的尺寸效应。结果表明，在表面等离子体激元的共振频率下，