Equalizing the near and far electromagnetic fields around particles made of different materials

TL;DR

This paper presents a method to make electromagnetic fields around particles of different materials, such as metals and dielectrics, identical by deriving formulas for their parameters, enabling control over near and far fields.

Contribution

It introduces explicit formulas to match electromagnetic responses of particles made of different materials, including metals and dielectrics, for the first time.

Findings

Dielectric particles can replicate the near fields of metallic nanoparticles with localized surface plasmons.

Explicit formulas relate material parameters to achieve identical electromagnetic responses.

Dielectric particles can also support magnetic resonances similar to exotic negative permeability materials.

Abstract

We demonstrate that the electromagnetic fields scattered by particles made of different materials can be equalized. Emphasize is placed first in metallic nanoparticles that host localized surface plasmons and it is shown that their electromagnetic fields can be identically reproduced with dielectric particles. We derive the explicit formulas relating the different constitutive parameters that yield identical electromagnetic responses. This method provides the dielectric permittivities of spherical particles that reproduce the strong near electric field intensities observed around metallic particles featuring localized surface plasmon resonances in optics or near infrared frequencies. We also demonstrate the ability of homogenous dielectric particles to host the magnetic resonances predicted for exotic materials with negative permeability.