Phonon-Plasmon coupling in pillared phononic crystals mediated by surface acoustic waves
Abstract
We study theoretically the phonon-plasmon interaction in a multilayered structure supporting metallic nano-pillars or ridges. The acoustic vibrations of the pillars, excited by means of an incident surface acoustic wave (Sezawa wave), interact with localized plasmons of metal-insulator-metal type. The strongest couplings are obtained for the compressional resonance of the pillars as well as for a symmetric flexural mode resulting from the interaction between two adjacent ridges. Some Sezawa modes well-confined near the surface can also exhibit high optomechanic couplings.