Charge distribution induced inside complex plasmonic nanoparticles

Area of Science:

• Nanophotonics and Plasmonics
• Computational Electromagnetics
• Materials Science

Background:

• Plasmonic nanoparticles exhibit unique optical properties due to collective electron oscillations.
• Understanding charge distribution is crucial for interpreting plasmonic resonances and spectral features.
• Existing methods may lack versatility for complex nanostructures.

Purpose of the Study:

• To develop a versatile numerical technique for computing 3D charge distribution in plasmonic nanoparticles.
• To enable the investigation of charge dynamics in arbitrarily complex plasmonic nanostructures.
• To link charge distribution to the nature of multipolar plasmon modes and spectral features.

Main Methods:

• A novel numerical technique is presented for calculating volumetric charge density.
• The method is applied to model plasmonic nanostructures, including gold nanotriangles and nano-antennas.
• The computed charge distributions are used to identify and analyze multipolar plasmon modes.

Main Results:

• The technique successfully computes the 3D charge distribution within plasmonic nanoparticles.
• The method elucidates the physical origin of spectral features by analyzing charge distribution.
• The study demonstrates the ability to define and compute multipolar expansion terms from volume charge density.

Conclusions:

• The developed numerical technique offers a versatile tool for analyzing plasmonic nanostructures.
• This method provides insights into the relationship between charge distribution and plasmonic resonances.
• The approach facilitates a deeper understanding of multipolar plasmon modes and their spectral contributions.