Nature Nanotechnology ( IF 38.3 ) Pub Date : 2020-08-10 , DOI: 10.1038/s41565-020-0753-y Chao-Yu Li 1 , Sai Duan 2, 3 , Bao-Ying Wen 1 , Song-Bo Li 1 , Murugavel Kathiresan 4 , Li-Qiang Xie 1 , Shu Chen 1 , Jason R Anema 1 , Bing-Wei Mao 1 , Yi Luo 5 , Zhong-Qun Tian 1 , Jian-Feng Li 1
The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres1,2,3,4,5,6. Plasmon-enhanced applications include advanced spectroscopies7,8,9,10, optomechanics11, optomagnetics12 and biosensing13,14,15,16,17. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.
中文翻译:
观察纳米腔中的非均匀等离子体场分布。
基于等离子体的技术的进步依赖于对耦合纳米结构1,2,3,4,5,6产生的增强电磁场的特性的理解。等离子增强应用包括高级光谱学7,8,9,10,光机械学11,光磁学12和生物传感13,14,15,16,17. 然而,精确确定纳米间隙内的等离子体场强度分布仍然具有挑战性。在这里,我们展示了由一组基于紫精的自组装单层制成的分子标尺,我们用它精确测量了具有 ~2-Å 空间分辨率的等离子体纳米腔内的场分布。我们观察到异常大的等离子体场强度不均匀性,我们将其归因于纳米腔中等离子体梳的形成。因此,我们认为应该谨慎使用分子单层的普遍采用的连续介质近似。