论文标题
多极跨面中的空间对称性：从不对称的角传感器到多极外部手性
Spatial Symmetries in Multipolar Metasurfaces: From Asymmetric Angular Transmittance to Multipolar Extrinsic Chirality
论文作者
论文摘要
我们提出了一个将元图的空间对称性连接到其材料参数张量和散射矩阵的框架。这提供了一种简单而有效的方法，可以轻松确定跨表面散射响应的性质，例如手性或不对称传播，以及在均质化过程的前景中应考虑其哪些有效材料参数。 与现有技术相反，这种方法不需要对群体理论或复杂的数值模拟方案的任何先验知识，因此使其快速，易于使用且易于访问。它的工作原理包括递归求解适用于偶极和四极物质参数的对称性变异条件，包括非局部相互作用以及元表面散射矩阵。因此，总体过程仅需要列出元图的空间对称性。 使用所提出的框架，我们证明了多极外在手性的存在，这是一种手性反应的形式，即使在正常发生率下，在几何上对现场梯度敏感的几何结构中都可以实现。
We propose a framework that connects the spatial symmetries of a metasurface to its material parameter tensors and its scattering matrix. This provides a simple yet effective way to effortlessly determine properties of a metasurface scattering response, such as chirality or asymmetric transmission, and which of its effective material parameters should be taken into account in the prospect of a homogenization procedure. In contrast to existing techniques, this approach does not require any a priori knowledge of group theory or complicated numerical simulation schemes, hence making it fast, easy to use and accessible. Its working principle consists in recursively solving symmetry-invariance conditions that apply to dipolar and quadrupolar material parameters, which include nonlocal interactions, as well as the metasurface scattering matrix. The overall process thus only requires listing the spatial symmetries of the metasurface. Using the proposed framework, we demonstrate the existence of multipolar extrinsic chirality, which is a form of chiral response that is achieved in geometrically achiral structures sensitive to field gradients even at normal incidence.
