Sidebands in the light absorption of driven metallic nanoparticles

TL;DR

This paper models the surface plasmon dynamics in laser-driven metallic nanoparticles using a master-equation approach, predicting sidebands in absorption spectra during pump-probe experiments.

Contribution

It introduces a simplified two-level model for plasmon dynamics and predicts sidebands in absorption spectra, advancing understanding of nanoparticle optical responses.

Findings

Two collective levels suffice to describe plasmon dynamics.

Sidebands appear in the absorption spectrum during pump-probe experiments.

The model applies across different excitation regimes.

Abstract

The dynamics of the surface plasmon in laser-driven metallic nanoparticles is described by means of a master-equation formalism. Within the Markov approximation, the dynamics is studied for different regimes ranging from weak excitation in photoabsorption experiments to strong excitation in pump-probe spectroscopy. It is shown that two collective levels are sufficient to describe the dynamics of the surface plasmon. On this basis, we predict the appearance of sidebands in the absorption spectrum of the probe laser field in pump-probe experiments.