Which resonances in small metallic nanoparticles are plasmonic?

Published

November 3, 2014

Author(s)

Emily Townsend, Garnett W. Bryant

Abstract

We use time-dependent density functional theory to examine the character of various resonances corresponding to peaks in the optical response of small metallic nanoparticles. Each resonance has both "sloshing" and "inversion" character. The sloshing mode is an oscillation in the occupation of the shells nearest the Fermi energy, transferring charge back and forth from below the Fermi level to above it. It results in oscillation in charge density near the surface of the particle. Inversions monotonically move charge from occupied to unoccupied states, and result in oscillation in charge density in the core of the particle. We also discuss the dependence of the optical response on the size of the simulation grid, noting that the character of resonances appears stable with respect to changes in simulation size, even though the details of the spectrum change. This makes a reliable characterization possible. We consider what characteristics are important in deciding that a resonance is plasmonic.

Citation

Journal of Optics

Volume

16

Issue

11

Pub Type

Journals

Download Paper

https://doi.org/10.1088/2040-8978/16/11/114022

Local Download

Keywords

Quantum Plasmonics, Metallic Nanoparticles, Time-Dependent Density, Functional Theory

Citation

Townsend, E. and Bryant, G. (2014), Which resonances in small metallic nanoparticles are plasmonic?, Journal of Optics, [online], https://doi.org/10.1088/2040-8978/16/11/114022, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916323 (Accessed October 10, 2025)