论文标题
各向异性范德华纳米颗粒中的Anapole态和散射挠度效应
Anapole states and scattering deflection effects in anisotropic van der Waals nanoparticles
论文作者
论文摘要
属于范德华材料类别的过渡金属二分法(TMDC)是光电子和光子学的有前途的材料。特别是,当使用有限厚度的纳米结构中,它们的巨型光学各向异性可能会产生重要的光学效应。在本文中,我们从各向异性MOS2纳米固定器中研究了光散射行为,并强调了其独特的特征优于相同形状的常规硅颗粒的响应。我们建立了两个显着现象,它们以优化的几何形状出现在同一MOS2粒子中。第一个是与电偶极氨基烷态激发相关的纯磁偶极散射。先前仅在核壳混合体(金属/介电)系统中报道,现在在全丝粒子中证明了这一点。第二种现象是远场中的超级反射:最大散射可能会在各个方向上发生,包括前向,后,侧裂纹,具体取决于MOS2纳米辅导员的相互取向以及事件波的相互取向。与以不同频率出现在纳米颗粒中的众所周知的Kerker和反kerker效应相反,可以通过以恒定的入射光频率旋转粒子来实现超偏置。我们的结果促进了纳米结构的各向异性TMDC的功能光学设备的开发,并可能鼓励基于高度各向异性材料的元元素进行进一步研究。
Transition metal dichalcogenides (TMDCs), belonging to the class of van der Waals materials, are promising materials for optoelectronics and photonics. In particular, their giant optical anisotropy may enable important optical effects when employed in nanostructures with finite thickness. In this paper, we theoretically and numerically study light scattering behavior from anisotropic MoS2 nanocylinders, and highlight its distinct features advantageous over the response of conventional silicon particles of the same shape. We establish two remarkable phenomena, appearing in the same MoS2 particle with optimized geometry. The first one is a pure magnetic dipole scattering associated with the excitation of the electric-dipole anapole states. Previously reported in core-shell hybrid (metal/dielectric) systems only, it is now demonstrated in an all-dielectric particle. The second phenomenon is the super-deflection in the far field: the maximum scattering may occur over a wide range of directions, including forward-, backward- and side-scattering depending on the mutual orientation of the MoS2 nanocylinder and the incident wave. In contrast to the well-known Kerker and anti-Kerker effects, which appear in nanoparticles at different frequencies, the super-deflection can be achieved by rotating the particle at a constant frequency of incident light. Our results facilitate the development of functional optical devices incorporating nanostructured anisotropic TMDCs and may encourage further research in meta-optics based on highly anisotropic materials.