Experimental demonstration of the microscopic origin of circular dichroism in two-dimensional metamaterials.
Experimental demonstration of the microscopic origin of circular dichroism in two-dimensional metamaterials.
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DOI：
10.1038/ncomms12045
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发表时间：
2016-06-22
影响因子：
16.6
通讯作者：
Shvets G
中科院分区：
文献类型：
--
作者：
Khanikaev AB;Arju N;Fan Z;Purtseladze D;Lu F;Lee J;Sarriugarte P;Schnell M;Hillenbrand R;Belkin MA;Shvets G
光学活性和圆二向色性是一种有趣的物理现象，起源于光与三维空间中的手性分子或其他缺乏镜面对称性的纳米物体的相互作用。虽然手性光学性质在大多数自然产生的材料中都很弱，但它们可以在被称为手性超材料的合成光学介质中进行工程设计并显著增强，其中它们的构建块的空间对称性在纳米尺度上被打破。虽然最初在3D结构中发现了圆二向色性，但圆二向色性也可以出现在二维(2D)亚表面中。由此产生的圆二向色性的起源是相当微妙的，并与组成偏分子的非辐射(欧姆)耗散有关。由于这种耗散发生在纳米尺度上，这种效应从未被实验探测和可视化过。利用最近开发的一套纳米尺度测量工具，我们证实了纳米结构准表面中的圆二向色性是由于手性相关的欧姆加热而发生的。二维手性材料中的欧姆耗散效应从未得到实验验证。在这里，Khanikaev等人。证明了纳米结构准表面中的圆二向色性是由于手性相关的欧姆加热引起的。
Optical activity and circular dichroism are fascinating physical phenomena originating from the interaction of light with chiral molecules or other nano objects lacking mirror symmetries in three-dimensional (3D) space. While chiral optical properties are weak in most of naturally occurring materials, they can be engineered and significantly enhanced in synthetic optical media known as chiral metamaterials, where the spatial symmetry of their building blocks is broken on a nanoscale. Although originally discovered in 3D structures, circular dichroism can also emerge in a two-dimensional (2D) metasurface. The origin of the resulting circular dichroism is rather subtle, and is related to non-radiative (Ohmic) dissipation of the constituent metamolecules. Because such dissipation occurs on a nanoscale, this effect has never been experimentally probed and visualized. Using a suite of recently developed nanoscale-measurement tools, we establish that the circular dichroism in a nanostructured metasurface occurs due to handedness-dependent Ohmic heating. The effect of Ohmic dissipation in two-dimensional chiral materials has never been experimentally verified. Here, Khanikaev et al. demonstrate that the circular dichroism in a nanostructured metasurface occurs due to handedness-dependent Ohmic heating.