Stable Fano-like plasmonic resonance: its impact on the reversal of far-and near-field optical binding force

• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2020,（4）
• 页码范围: 89-105
• 页数: 17页
• 语种: 英文

摘要

Even for a 100 nm interparticle distance or a small change in particle shape,optical Fano-like plasmonic resonance mode usually vanishes completely.It would be remarkable if stable Fanolike resonance could somehow be achieved in distinctly shaped nanoparticles for more than 1 μm interparticle distance,which corresponds to the far electromagnetic field region.If such farfield Fano-like plasmonic resonance can be achieved,controlling the reversal of the far-field binding force can be attained,like the currently reported reversals for near-field cases.In this work,we have proposed an optical set-up to achieve such a robust and stable Fano-like plasmonic resonance,and comparatively studied its remarkable impact on controlling the reversal of near-and far-field optical binding forces.In our proposed set-up,the distinctly shaped plasmonic tetramers are half immersed (i.e.air-benzene) in an inhomogeneous dielectric interface and illuminated by circular polarized light.We have demonstrated significant differences between near-and far-field optical binding forces along with the Lorentz force field,which partially depends on the object's shape.A clear connection is shown between the far-field binding force and the resonant modes,along with a generic mechanism to achieve controllable Fano-like plasmonic resonance and the reversal of the optical binding force in both far-and nearfield configurations.