2007/01/31 by C. Giannetti, Claudio Giannetti, B. Revaz +16 · 2 citations
Engineering · Physics and Astronomy · #Acoustic Wave Resonator Technologies #Near-Field Optical Microscopy #Plasmonic and Surface Plasmon Research #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.76.125413
13 pages, 10 figures
arxiv created 2007/02/07 · openalex publication_date 2007/09/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The ultrafast thermal and mechanical dynamics of a two-dimensional lattice of metallic nanodisks has been studied by near-infrared pump-probe diffraction measurements over a temporal range spanning from 100\phantom\rule0.3em0exfs to several nanoseconds. The experiments demonstrate that in these systems a surface acoustic wave (SAW), with a wave vector given by the reciprocal periodicity of the two-dimensional array, can be excited by \ensuremath∼120\phantom\rule0.3em0exfs Ti:sapphire laser pulses. In order to clarify the interaction between the nanodisks and the substrate, numerical calculations of the elastic eigenmodes and simulations of the thermal dynamics of the system are developed through finite-element analysis. We unambiguously show that the observed SAW velocity shift originates from the mechanical interaction between the SAWs and the nanodisks, while the correlated SAW damping is due to the energy radiation into the substrate.