Toroidal dipole induced transparency for core-shell nanoparticles

Abstract

We investigate the scattering properties of spherical nanoparticles by employing a Cartesian multipole expansion method which has incorporated radiating toroidal multipoles. It is shown that toroidal dipoles, which are negligible under long-wavelength approximations, can be excited within high-permittivity dielectric nanoparticles and significantly influence the scattering profile in the optical regime. We further reveal that the scattering transparencies of core-shell plasmonic nanoparticles can be classified into two categories: i) the trivial transparency with no effective multipole excitations within the particle, and ii) the non-trivial one induced by the destructive interferences of induced electric and toroidal multipoles. The incorporation of toroidal moments offers new insights into the study into nanoparticle scattering in both the near- and far-fields, which may shed new light to many related applications, such as biosensing, nanoantennas, photovoltaic devices and so on.

15 pages and 3 figures

References in corpus (9)

• Topological Photonics
• Two-Dimensional Material Nanophotonics
• Achieving transparency with plasmonic coatings
• Directional visible light scattering by silicon nanoparticles
• Magnetic light
• Backward Pulling Force from a Forward Propagating Beam
• Ultra-directional forward scattering by individual core-shell nanoparticles
• Toroidal dipole response in a multifold double-ring metamaterial
• Control of light scattering by nanoparticles with optically-induced magnetic responses

Cited by in corpus (25)

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• Nonlocal homogenization of PT-symmetric multilayered structures
• On the dynamic toroidal multipoles from localized electric current distributions
• Non-radiating sources, dynamic anapole and Aharonov-Bohm effect
• Elusive pure anapole excitation in homogenous spherical nanoparticles with radial anisotropy
• Electromagnetic sources beyond common multipoles
• Cylindrical vector beams reveal radiationless anapole condition in a resonant state
• Efficient excitation and tuning of toroidal dipoles within individual homogenous nanoparticles
• Unidirectional scattering induced by the toroidal dipole moment in the system of plasmonic nanoparticles
• A Generic Minimal Discrete Model for Toroidal Moments and Its Experimental Realization
• Scattering invisibility with free-space field enhancement of all-dielectric nanoparticles
• Inverse design with flexible design targets via deep learning: Tailoring of electric and magnetic multipole scattering from nano-spheres
• Tuning toroidal dipole resonances in dielectric metamolecules by an additional electric dipolar response
• Global Mie Scattering
• Localized magnetic plasmons in all-dielectric mu<0 metastructures
• Simultaneous inverse design of materials and parameters of core-shell nanoparticle via deep-learning: Demonstration of dipole resonance engineering
• Optical anapole mode in nanostructured lithium niobate for enhancing second harmonic generation
• Electric and magnetic toroidal dipole excitations in core-shell spheres
• Electromagnetic Duality Protected Scattering Properties of Nonmagnetic Particles
• Nonradiative to Superscattering Switch with Phase-Change Materials
• Gain-controlled directional scattering in core-shell nanoparticles mediated by magnetic toroidal dipoles