Radial breathing modes coupling in plasmonic molecules.
Fajun Xiao, Guanglin Wang, Wuyun Shang, Weiren Zhu, Lei Han, Ting Mei, Malin Premaratne, Jianlin Zhao
Optics Express | Published : 2019
Metallic hexamer, very much the plasmonic analog of benzene molecule, provides an ideal platform to mimic modes coupling and hybridization in molecular systems. To demonstrate this, we present a detailed study on radial breathing mode (RBM) coupling in a plasmonic dual-hexamers. We excite RBMs of hexamers by symmetrically matching the polarization state of the illumination with the distribution of electric dipole moments of the dual-hexamer. It is found that the RBM coupling exhibits a nonexponential decay when the inter-hexamer separation is increased, owing to the dark mode nature of RBM. When the outer hexamer is subjected to the in-plane twisting, resonant wavelengths of two coupled RBMs..View full abstract