Origin of the anapole condition as revealed by a simple expansion beyond the toroidal multipole

Li, Shi-Qiang; Crozier, Kenneth B.

doi:10.1103/physrevb.97.245423

Cited by 55 publications

(48 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Multipolar decomposition can be carried out in both spherical and Cartesian bases based on light‐induced polarization or displacement current,

J (r) = - i ω P (r) = - i ω ε_{0} (ε - 1) E (r)

, where

E (r)

is the total electric field inside the particle. In the context of a multipole expansion, the origin of toroidal multipole moments can be understood from first principles.…”

Section: Anapole Concept In Metaopticsmentioning

confidence: 99%

Optical Anapoles: Concepts and Applications

Baryshnikova

Smirnova

Luk’yanchuk

et al. 2019

Advanced Optical Materials

225

177

View full text Add to dashboard Cite

Interference of electromagnetic modes supported by subwavelength photonic structures is one of the key concepts that underpins the nanoscale control of light in metaoptics. It drives the whole realm of all‐dielectric Mie‐resonant nanophotonics with many applications for low‐loss nanoscale optical antennas, metasurfaces, and metadevices. Specifically, interference of the electric and toroidal dipole moments results in a very peculiar, low‐radiating optical state associated with the concept of optical anapole. Here, the physics of multimode interferences and multipolar interplay in nanostructures is uncovered with an intriguing example of the optical anapole. The recently emerged field of anapole electrodynamics is reviewed, explicating its relevance to multipolar nanophotonics, including direct experimental observations, manifestations in nonlinear optics, and rapidly expanding applications in nanoantennas, active photonics, and metamaterials.

show abstract

“…Multipolar decomposition can be carried out in both spherical and Cartesian bases based on light‐induced polarization or displacement current,

J (r) = - i ω P (r) = - i ω ε_{0} (ε - 1) E (r)

, where

E (r)

is the total electric field inside the particle. In the context of a multipole expansion, the origin of toroidal multipole moments can be understood from first principles.…”

Section: Anapole Concept In Metaopticsmentioning

confidence: 99%

Optical Anapoles: Concepts and Applications

Baryshnikova

Smirnova

Luk’yanchuk

et al. 2019

Advanced Optical Materials

225

177

View full text Add to dashboard Cite

show abstract

“…Toroidal moments are not limited to the electric type; there are few works showing the existence of the corrections to magnetic dipole (MD) moments, which can be associated with the magnetic toroidal dipoles . Thereby, the electric and magnetic toroidal moments complement the conventional electric and magnetic ones and form a full set of all possible sign permutations under the inversion of space

r \to - r

and time

t \to - t

…”

Section: Introductionmentioning

confidence: 99%

“…The electromagnetic field generated by toroidal dipole moments can interfere with the fields produced by electric and magnetic dipoles constructively forming super‐dipole states, or destructively giving rise to nonradiative current configurations—“anapole” states . Now, the study of nonradiative current configurations is in its initial stage, and only electric dipole “anapole” states of different orders and magnetic “anapoles” (destructive interference of a magnetic dipole moment and a corresponding toroidal multipole) are shown. The Mie theory allows the numerous zeros of the scattering coefficients for spherical particles to be investigated, but does not allow the basic and/or toroidal contributions corresponding to different current configurations to be distinguished .…”

Section: Introductionmentioning

confidence: 99%

The High‐Order Toroidal Moments and Anapole States in All‐Dielectric Photonics

Gurvitz

Ladutenko

Dergachev

et al. 2019

Laser & Photonics Reviews

181

165

View full text Add to dashboard Cite

All‐dielectric nanophotonics attracts ever increasing attention nowadays due to the possibility of controlling and configuring light scattering on high‐index semiconductor nanoparticles. It opens a room of opportunities for designing novel types of nanoscale elements and devices, and paves the way for advanced technologies of light energy manipulation. One of the exciting and promising prospects is associated with utilizing the so‐called toroidal moment, being the result of poloidal currents excitation, and anapole states, corresponding to the interference of dipole and toroidal electric moments. Here, higher‐order toroidal moments of both types (up to the electric octupole toroidal moment) are presented and investigated in detail via the direct Cartesian multipole decomposition allowing new near‐ and far‐field configurations to be obtained. Poloidal currents can be associated with vortex‐like distributions of the displacement currents inside nanoparticles, revealing the physical meaning of the high‐order toroidal moments and the convenience of the Cartesian multipoles as an auxiliary tool for analysis. High‐order nonradiating anapole states accompanied by the excitation of intense near‐fields are demonstrated. It is believed that the results are of high importance for both the fundamental understanding of light scattering by high‐index particles and a variety of nanophotonics applications and light governing on nanoscale.

show abstract

“…Thus, we here utilize the Cartesian multipole decomposition method to show the scattering contributions of TD mode and other electromagnetic multipoles. To be more accurate, we apply a two-dimensional (2d) Cartesian decomposition conducted in a recent theoretical work [29], instead of using a three-dimensional decomposition method in a extended 2d metamolecule [8]. Besides, the total EM fields are solved by finite-difference time-domain method (FDTD).…”

Section: Cartesian Multipole Decomposition Methodsmentioning

confidence: 99%

Tuning toroidal dipole resonances in dielectric metamolecules by an additional electric dipolar response

Huang

Wang

Zhao

2019

Journal of Applied Physics

View full text Add to dashboard Cite

With the rise of artificial magnetism and metamaterials, the toroidal family recently attracts more attention for its unique properties. Here we propose an all-dielectric pentamer metamolecule consisting of nano-cylinders with two toroidal dipolar resonances, whose frequencies, EM distributions and Q factor can be efficiently tuned due to the additional electric dipole mode offered by a central cylinder. To further reveal the underlying coupling effects and formation mechanism of toroidal responses, the multiple scattering theory is adopted. It is found that the first toroidal dipole mode, which can be tuned from 2.21 to 3.55 µm, is mainly induced by a collective electric dipolar resonance, while the second one, which can be tuned from 1.53 to 1.84 µm, relies on the cross coupling of both electric and magnetic dipolar responses. The proposed low-loss metamolecule and modes coupling analyses may pave the way for active design of toroidal responses in advanced optical devices.

show abstract

Origin of the anapole condition as revealed by a simple expansion beyond the toroidal multipole

Cited by 55 publications

References 33 publications

Optical Anapoles: Concepts and Applications

Optical Anapoles: Concepts and Applications

The High‐Order Toroidal Moments and Anapole States in All‐Dielectric Photonics

Tuning toroidal dipole resonances in dielectric metamolecules by an additional electric dipolar response

Contact Info

Product

Resources

About