Nonlocal Optical Response of Particle Plasmons in Single Gold Nanorods

TL;DR

This study investigates the nonlocal optical response of particle plasmons in single gold nanorods, revealing less significant damping effects than in coupled systems and demonstrating the effectiveness of dark-field spectroscopy for such analysis.

Contribution

It introduces a comparison between experimental spectra and nonlocal response theory models for single nanoparticles, highlighting mesoscopic effects and the utility of dark-field spectroscopy.

Findings

Nonlocal damping effects are less significant in single nanoparticles.

Dark-field spectroscopy effectively probes nonlocal plasmon responses.

Results inform the design of nanophotonic devices.

Abstract

Particle plasmons in metal nanoparticles have primarily been investigated through the use of local optical response approximations. However, as nanoparticle size approaches the average distance of electrons to the metal surface, mesoscopic effects such as size-dependent plasmon linewidth broadening and resonance energy blue shifts are expected to become observable. In this work, we compared the experimental spectral characteristics with simulated values obtained using a generalized nonlocal optical response theory-based local analogue model. Our results show that the nonlocal plasmon damping effects in single nanoparticles are less significant compared to those observed in plasmon-coupled systems. Moreover, our study demonstrates that single-particle dark-field spectroscopy is an effective tool for investigating the nonlocal optical response of particle plasmons in single nanoparticles. These results have important implications for the rational design of novel nanophotonic devices.