Li Zhancheng, Liu Wenwei, Cheng Hua, Chen Shuqi, Tian Jianguo
The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Institute of Applied Physics, Nankai University, Tianjin, 300071, China.
Sci Rep. 2017 Aug 15;7(1):8204. doi: 10.1038/s41598-017-08527-4.
Chirality is a nearly ubiquitous natural phenomenon. Its minute presence in most naturally occurring materials makes it incredibly difficult to detect. Recent advances in metasurfaces indicate that they exhibit devisable chirality in novel forms; this finding offers an effective opening for studying chirality and its features in such nanostructures. These metasurfaces display vast possibilities for highly sensitive chirality discrimination in biological and chemical systems. Here, we show that two-layer metasurfaces based on twisted nanorods can generate giant spin-selective transmission and support engineered chirality in the near-infrared region. Two designed metasurfaces with opposite spin-selective transmission are proposed for treatment as enantiomers and can be used widely for spin selection and enhanced chiral sensing. Specifically, we demonstrate that the chirality in these proposed metasurfaces can be adjusted effectively by simply changing the orientation angle between the twisted nanorods. Our results offer simple and straightforward rules for chirality engineering in metasurfaces and suggest intriguing possibilities for the applications of such metasurfaces in spin optics and chiral sensing.
手性是一种几乎普遍存在的自然现象。它在大多数天然材料中的微量存在使得其极难被检测到。超表面的最新进展表明，它们以新颖的形式展现出可设计的手性；这一发现为研究此类纳米结构中的手性及其特性提供了一个有效的切入点。这些超表面在生物和化学系统中进行高灵敏度手性辨别方面展现出巨大潜力。在此，我们表明基于扭曲纳米棒的双层超表面能够在近红外区域产生巨大的自旋选择性透射并支持工程化手性。提出了两种具有相反自旋选择性透射的设计超表面，将其作为对映体进行处理，可广泛用于自旋选择和增强手性传感。具体而言，我们证明了通过简单改变扭曲纳米棒之间的取向角，就能有效调节这些所提出超表面中的手性。我们的结果为超表面中的手性工程提供了简单直接的规则，并为这类超表面在自旋光学和手性传感中的应用暗示了有趣的可能性。
