Rotational motion of charges in plasmonic nanostructures plays an important role in transferring angular momentum between light and matter on the nanometer scale. Although sophisticated control of rotational charge motion has been achieved using spatially structured light, its extension to simultaneous excitation of the same charge motion in multiple nanostructures is not straightforward. In this study, we perform model calculations to show that spatially homogeneous circularly polarized (CP) light can excite rotational charge motions with a high degrees of freedom by exploiting the rotational symmetry of the plasmonic structure and that of the plasmon mode. Finite-difference time-domain simulations demonstrate selective excitation of rotational charge motion for both isolated nanoplates and periodic array structures, showing that complex charge rotations can be manipulated by plane CP waves in a wide range of plasmonic structures.

中文翻译：

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设计由圆偏振光激发的等离子体纳米结构上电荷密度的旋转运动


等离激元纳米结构中电荷的旋转运动在纳米尺度上光和物质之间传递角动量中起着重要作用。尽管已经使用空间结构光实现了对旋转电荷运动的复杂控制，但将其扩展到在多个纳米结构中同时激发相同的电荷运动并不简单。在这项研究中，我们进行了模型计算，以表明空间均匀圆偏振 （CP） 光可以通过利用等离激元结构和等离激元模式的旋转对称性来激发高自由度的旋转电荷运动。有限差分时域仿真证明了孤立纳米板和周期性阵列结构的旋转电荷运动的选择性激发，表明复杂的电荷旋转可以通过各种等离子体结构中的平面 CP 波来操纵。