Enhancement of artificial magnetism via resonant bianisotropy

TL;DR

This paper introduces a novel method to enhance artificial magnetic responses in all-dielectric nanostructures by exploiting resonant bianisotropy, enabling better control of magnetic light at the nanoscale.

Contribution

It proposes and analyzes a new approach using resonant bianisotropy in dielectric dimers to significantly increase magnetic polarizability and control in nanophotonic structures.

Findings

Magnetic polarizability can be tailored with 100% dynamical range.

Enhancement of magnetic response up to 36% over standalone particles.

Proper geometric arrangement enables flexible magnetic control.

Abstract

All-dielectric "magnetic light" nanophotonics based on high refractive index nanoparticles allows controlling magnetic component of light at nanoscale without having high dissipative losses. The artificial magnetic optical response of such nanoparticles originates from circular displacement currents excited inside those structures and strongly depends on geometry and dispersion of optical materials. Here a new approach for increasing magnetic response via resonant bianisotropy effect is proposed and analyzed. The key mechanism of enhancement is based on electric-magnetic interaction between two electrically and magnetically resonant nanoparticles of all-dielectric dimer nanoantenna. It was shown that proper geometrical arrangement of the dimer in respect to the incident illumination direction allows flexible control over all vectorial components of magnetic polarizability, tailoring the later in the dynamical range of 100 % and enhancement up to 36 % relative to performances of standalone spherical particles. The proposed approach provides pathways for designs of all-dielectric metamaterials and metasurfaces with strong magnetic response.