论文标题
双异性反应的多极理论
Multipolar theory of bianisotropic response
论文作者
论文摘要
元时间的双异构膜通常与它们的非局部反应以及被入射场诱导的电和磁偶极矩之间的相互耦合有关。在这项工作中，我们概括了双极反应对任意高阶多极共振病例的偶极子反应之外的理论。我们证明了双异型症仅是由于缺乏元素的反式对称性引起的。双症反应的强度通常随着元原子的大小而增加，但其起源与结构的对称性完全连接。作为双异性粒子的重要例子，我们考虑了一个三角形的棱镜，并显示了如何考虑高阶多物的考虑，可以防止违反偶极子近似中出现的动力学系数的Onsager-Casimir条件。开发的理论是迈向更深入地了解纳米antennas和meta原子的散射特性的重要一步。
Bianisotropy of metaatoms is usually associated with their nonlocal response and the mutual coupling between electric and magnetic dipole moments induced by the incident field. In this work, we generalize the theory of bianisotropy beyond the dipole response to the cases of arbitrary high-order multipole resonances. We demonstrate that bianisotropy is exclusively caused by the absence of the inversion symmetry of metaatoms. The strength of the bianisotropy response is normally increased with the size of a meta-atom but its origin is fully connected to the symmetry of the structure. As an important example of bianisotropic particle, we consider a triangular prism and show how accounting for the higher-order multipoles prevents the violation of the Onsager-Casimir conditions for kinetic coefficients appearing in the dipole approximation. The developed theory is an important step towards a deeper insight into the scattering properties of nanoantennas and meta-atoms.
