Double-Layer Chiral System with Induced Circular Dichroism by Near-Field Coupling
Double-Layer Chiral System with Induced Circular Dichroism by Near-Field Coupling
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DOI：
10.1021/acs.jpcc.1c08049
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
Ying Li;Yaqi Ren;Yu Bai;M. Ikram;Yue Xu;Yongkai Wang;Zhongyue Zhang
中科院分区：
文献类型：
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作者：
Ying Li;Yaqi Ren;Yu Bai;M. Ikram;Yue Xu;Yongkai Wang;Zhongyue Zhang
圆二色性（CD）广泛应用于对映体鉴定、光电检测和圆偏振装置。通过设计模板来改善易于制备的 3D 手性纳米结构的 CD 信号仍然是该领域的一个挑战。在此，双层纳米结构可以通过一次性电子束光刻（EBL）与电子束沉积相结合来制备，理论和实验表明其表现出CD效应。理论结果表明，双层纳米结构由于近场耦合而在层间形成强烈的局域电磁场，并且打破纳米结构对称性的不同部分的相对位置导致在圆偏振光（CPL）激发下扭曲磁场和传输的差异，从而产生CD效应。此外，臂位置的修改改变了结构的不对称性，由于放大的左右CPL传输差异而导致较大的CD效应。此外，通过改变 VO2state 来调节近场耦合，可以显着调节 CD 效应。这些结果提供了一种通过在上层和底层使用相同的纳米结构并操纵近场耦合来获得CD效应的方法。这种手性器件在手性识别、远程温度读出和化学反应的高级控制方面具有潜在的应用。
Circular dichroism (CD) is widely used in enantiomer identification, photodetection, and circular polarization devices. Improving the CD signal of easily prepared 3D chiral nanostructures by designing templates remains a challenge in this field. Herein, double-layer nanostructures, which can be prepared with one-time electron beam lithography (EBL) combined with electron beam deposition, are theoretically and experimentally shown to exhibit a CD effect. Theoretical results show that the double-layer nanostructures form strong local electromagnetic fields between the layers due to near-field coupling and that the relative positions of the different parts that break the symmetry of the nanostructures lead to differences in distorted magnetic fields and transmission under circularly polarized light (CPL) excitation, thereby producing CD effects. In addition, modifications in arm positions change the asymmetry of the structure, resulting in large CD effects due to amplified left and right CPL transmission differences. Furthermore, the CD effect can be tuned remarkably by changing the VO2state to regulate the near-field coupling. These results provide a way to obtain CD effects by using identical nanostructures in the upper and bottom layers and manipulating near-field coupling. Such chiral devices have potential applications in chiral recognition, remote temperature readout, and advanced control of chemical reactions.