Anderson localization in metallic nanoparticle arrays

TL;DR

This paper demonstrates that Anderson localization can be induced in metallic nonlinear nanoparticle arrays through a random external electric field, leading to highly confined localized electromagnetic patterns at wavelength scales.

Contribution

It reveals a new way to achieve Anderson localization in metallic nanoparticle arrays using random electric fields, expanding understanding of wave localization in plasmonic systems.

Findings

Random electric fields suppress ballistic dipole expansion.

Localized dipole intensity patterns form above a threshold randomness.

Localized patterns are confined to the wavelength scale.

Abstract

Anderson localization has been observed in various types of waves, such as matter waves, optical waves and acoustic waves. Here we reveal that the effect of Anderson localization can be also induced in metallic nonlinear nanoparticle arrays excited by a random electrically driving field. We find that the dipole-induced nonlinearity results in ballistic expansion of dipole intensity during evolution; while the randomness of the external driving field can suppress such an expansion. Increasing the strength of randomness above the threshold value, a localized pattern of dipole intensity can be generated in the metallic nanoparticle arrays. By means of statistics, the mean intensity distribution of the dipoles reveals the formation of Anderson localization. We further show that the generated Anderson localization is highly confined, with its size down to the scale of incident wavelength. The reported results might facilitate the manipulations of electromagnetic fields in the scale of wavelength.