Limits of silver nanotubes that allow to observe plasmons

The scattering and absorption of a plane H-polarized electromagnetic wave by a silver nanotube are investigated in a wide range of wavelengths. In computations, the complex permittivity of silver is taken from the published experimental data. The emerging plasmon resonances are revealed using the total scattering cross-section and the absorption cross-section and identified by the spatial distribution of the field amplitude near the object. We demonstrate that the resonances are still present, and the first and the second order plasmons are well observed even if the outer radius of the silver nanotube reaches 480 nm.