Localized surface plasmon modes of core-shell bimetal nanowires do not hybridize.

We investigate localized plasmon-mode resonances in the scattering and absorption of transversely polarized light by bimetal core-shell nanowires made of silver and gold, in two possible combinations, using an analytical solution and experimental data for metal permittivities. In particular, the influence of the metal shell thickness and material on these resonances is studied. We show that, unlike metal nanotubes with dielectric filling, bimetal wires do not display plasmon-mode hybridization.

Refractive-index sensitivities of hybrid surface-plasmon resonances for a core-shell circular silver nanotube sensor.

We study the scattering and absorption of an H-polarized plane electromagnetic wave by a circular silver nanotube in the visible range of wavelengths using the separation of variables. The computed spectra of the extinction cross section display several hybrid localized surface-plasmon resonances of the dipole and multipole type. Analytical equations are derived for their resonance wavelengths.