Journal Article

Observation of inhomogeneous plasmonic field distribution in a nanocavity

Song-Bo, Li, Zhong-Qun, Tian, Duan Sai, Kathiresan Murugavel, Anema, Jason R, Chen, Shu, Bing-Wei, Mao, Chao-Yu, Li, Bao-Ying, Wen, Luo, Yi, Li-Qiang, Xie, Jian-Feng, Li

2020

نظرة عامة

The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres1–6. Plasmon-enhanced applications include advanced spectroscopies7–10, optomechanics11, optomagnetics12 and biosensing13–17. 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.The strength of the plasmonic field between a plasmonic particle and a Au surface can be measured at ~2-Å resolution by following the Raman peaks of a suitably labelled self-assembly monolayer.

• الناشر: Nature Publishing Group
• موضوع: Coupling (molecular) / Electromagnetic fields / Inhomogeneity / Monolayers / Plasmonics / Self-assembly / Spatial discrimination / Spatial resolution