Resonant surface plasmons of a metal nanosphere treated as propagating surface plasmons**Project supported by the National Natural Science Foundation of China (Grant No. 11704058) and the Fundamental Research Funds for the Central Universities, China (Grant No. DUT16RC(3)111).

Abstract

On the assumption that the resonant surface plasmons on a spherical nanoparticle are formed by standing waves of two counter-propagating surface plasmon waves along the surface, by using Mie theory simulation, we find that the dispersions of surface plasmon resonant modes supported by silver nanospheres match with those of the surface plasmons on a semi-infinite medium-silver interface very well. This suggests that the resonant surface plasmons of a metal nanosphere can be treated as a propagating surface plasmon wave.