Colossal magnetic fields in high refractive index materials at microwave frequencies

Abstract

Resonant scattering of electromagnetic waves is a widely studied phenomenon with a vast range of applications that span completely different fields, from astronomy or meteorology to spectroscopy and optical circuitry. Despite being subject of intensive research for many decades, new fundamental aspects are still being uncovered, in connection with emerging areas, such as metamaterials and metasurfaces or quantum and topological optics, to mention some. In this work, we demonstrate yet one more novel phenomenon arising in the scattered near field of medium sized objects comprising high refractive index materials, which allows the generation of colossal local magnetic fields. In particular, we show that GHz radiation illuminating a high refractive index ceramic sphere creates instant magnetic near-fields comparable to those in neutron stars, opening up a new paradigm for creation of giant magnetic fields on the millimeter's scale.

Broadband Mechanically Tunable Metasurface Reflectivity Modulator in the Visible Spectrum

“…We also observe that relatively broad higher order multipolesthe electric and magnetic quadrupolesredshift and appear in the visible part of the spectrum. This resonance broadening leads to a lower field enhancement inside the structure . In Figure c, we study the absorption cross section of an isolated disk and vary the refractive index of the surrounding medium over a broad range to mimic the gradual change of the effective refractive index of the surrounding medium as disks enter the membrane.…”

Optical Phenomena in Dielectric Spheres Several Light Wavelengths in Size: A Review

“…The range of intermediate values of size parameter, q ~ 10, had remained a terra incognita in the field of optics for a long time; however, a number of new optical effects have been discovered in this field in the last years: optical and magnetic nanojets [17], optical ! @ Quasi-BIC (MO) nanovortices of subwavelength sizes [73], anapole nonradiative optical structures [131], high-order Fano resonances with generation of superstrong magnetic fields [78,106], etc. In this context the values q ~ 10 can be selected as a characteristic range of peculiar optical phenomena, caused by the effects of magnetic field localization.…”

“…The low energy dissipation in the material may also facilitate the field localization [105]. These high-order Fano resonances are promising for generating giant high-frequency magnetic fields inside dielectric particles [106]. Naturally, the size parameter must be larger for particles with a smaller refractive index than for the particles having a high refractive index.…”

“…For the visible spectrum, corresponds to a particle size of about 10 μm. In microwave materials with a high permittivity (ε > 100) strong amplification of magnetic fields can be observed even in the range of the first Fano resonances [106].…”

Transverse Kerker effect in all-dielectric spheroidal particles

“…These kind ceramics provide extremely high dielectric permittivity (up to 180) in microwave with an associated loss tangent in the range (see Refs. 34 , 35 ). In our frequency range, the sample loss tangent is and at a frequency of 1.6–2.6 GHz 34 .…”