Propagation of optical excitations by dipolar interactions in metal nanoparticle chains
摘要
Dispersion relations for dipolar modes propagating along a chain of metal nanoparticles are calculated by solving the full Maxwell equations, including radiation damping. The nanoparticles are treated as point dipoles, which means the results are valid only for a/d <= 1/3, where a is the particle radius and d the spacing. The discrete modes for a finite chain are first calculated, then these are mapped onto the dispersion relations appropriate for the infinite chain. Computed results are given for a chain of 50-nm diameter Ag spheres spaced by 75 nm. We find large deviations from previous quasistatic results: Transverse modes interact strongly with the light line. Longitudinal modes develop a bandwidth more than twice as large, resulting in a group velocity that is more than doubled. All modes for which k_mode <= w/c show strongly enhanced decay due to radiation damping.
引用
@article{arxiv.physics/0408003,
title = {Propagation of optical excitations by dipolar interactions in metal nanoparticle chains},
author = {W. H. Weber and G. W. Ford},
journal= {arXiv preprint arXiv:physics/0408003},
year = {2009}
}
备注
26 pages, 7 figures, 2 tables. to appear in Phys. Rev. B