It is revealed that the unique properties of ultrathin metasurface resonators can improve magnetic resonance imaging dramatically. A formed when an array metallic wires placed inside a scanner under studied object and substantial enhancement radio-frequency field achieved by means subwavelength manipulation with metasurface, also allowing improved image resolution.

Abstract The Purcell effect is defined as a modification of the spontaneous emission rate quantum emitter at presence resonant cavity. However, change an caused by environment has classical counterpart. Any small antenna tuned to resonance can be described oscillator with radiative losses and on its radiation modeled measured in terms resistance, similar emitter. We exploit this analogue behavior develop general approach for calculating factors different systems various frequency ranges...

Abstract Topological phase transitions in condensed matter systems give rise to exotic states of such as topological insulators, superconductors, and superfluids. Photonic open a whole new realm research technological opportunities, exhibiting number important distinctions from their counterparts. modes can leak into free space, which makes it possible probe photonic phases by spectroscopic means via Fano resonances. Based on this idea, we develop technique retrieve the properties...

We suggest a novel type of photonic topological edge states in zigzag arrays dielectric nanoparticles based on optically induced magnetic Mie resonances. verify our general concept by the proof-of-principle microwave experiments with spherical particles, and demonstrate, experimentally, ability to control subwavelength topologically protected electromagnetic modes changing polarization incident wave.

We propose a simple realization of topological edge states in zigzag chains plasmonic nanoparticles, mimicking the Kitaev model Majorana fermions. demonstrate one-to-one correspondence between coupled dipole equations chain and Bogoliubov-de-Gennes for quantum wire on top superconductor support analytical theory by full-wave electromagnetic simulations. reveal that localized plasmons can be excited selectively at both edges nanoparticles depending incident plane wave polarization.

Topological photonics has emerged recently as a smart approach for realizing robust optical circuitry, and the study of nonlinear effects is expected to open door tunability photonic topological states. Here we realize experimentally nonlinearity-induced spectral tuning electromagnetic edge states in arrays coupled resonators pump-probe regime. When nonlinearity weak, observe that frequencies exhibit shifts concentrated mainly at mode affecting only weakly bulk modes. For strong pumping,...

Being motivated by the recent theoretical proposal of nanoantennas based on high-permittivity dielectric spheres [A. E. Krasnok et al., JETP Lett. 94, 22113 (2011)], we suggest and verify experimentally concept all-dielectric antennas in microwave frequency range. In addition to electric resonance, each sphere exhibits a very strong magnetic resulting narrow radiation pattern overall high directivity such antennas. We find an excellent agreement between experimental data numerical results...

In this paper, we have studied a practical design of broadband linear-to-circular polarizer based on self-complementary metasurface composed zigzag-shaped metal strips printed dielectric substrate. The term indicates that the structure is identical to its complement, except for some translation smaller than periodicity. This property together with nonresonant response unit cells ensures conversion from linear polarization circular polarization. Although experimentally achieved relative...

We demonstrate a robust pseudospin- and valley-polarized one-way Klein tunneling topological edge states.

Developments in metamaterials and related structures such as metasurfaces have opened up new possibilities designing materials devices with unique properties. Here we report a hybrid metasurface structure, comprising two-dimensional metamaterial surface very high permittivity dielectric substrate, that has been designed to enhance the local performance of an ultra-high field MRI scanner. This flexible compact resonant structure is first which can be integrated multi-element close-fitting...

Recently introduced field of topological photonics aims to explore the concepts insulators for novel phenomena in optics. Here polymeric chains subwavelength silicon nanodisks are studied and it is demonstrated that these can support two types edge modes based on magnetic electric Mie resonances, their properties fully dictated by spatial arrangement nanoparticles chain. It observed experimentally described how theoretically phase transitions at nanoscale define a change from trivial...

In this work, we have demonstrated that self-complementary metasurfaces can provide linear-to-circular polarization conversion. For illustration of general approach, studied several particular structures based on periodic patterns etched metal sheets negligible thickness. The advantage using over previous proposals thin polarizers is the rigorous constancy phase difference between transmission (or reflection) coefficients corresponding to orthogonal linear polarizations, which just...

We report on the first experimental observation of topological edge states in zigzag chains plasmonic nanodisks.

We study waveguiding of the electromagnetic energy below diffraction limit with arrays dielectric nanoparticles through excitation both electric and magnetic Mie resonances. analyze dispersion characteristics such coupled-resonator optical waveguides by means coupled-dipole approximation then verify validity model comparing results direct numerical simulations. reveal that a chain silicon realistic material losses can guide light for distances exceeding several tens micrometers, which is...

Abstract Existence of robust edge states at interfaces topologically dissimilar systems is one the most fascinating manifestations a novel nontrivial state matter, topological insulator . Such were originally predicted and discovered in condensed matter physics, but they find their counterparts other fields including physics classical waves electromagnetism. Here, we present first experimental realization for electromagnetic based on engineered bianisotropic metamaterials By employing...

The radiation dynamics of optical emitters can be manipulated by properly designed material structures providing high local density photonic states, a phenomenon often referred to as the Purcell effect. Plasmonic nanorod metamaterials with hyperbolic dispersion electromagnetic modes are believed deliver significant enhancement both broadband and non-resonant nature. Here, we have investigated finite-size cavities formed shown that main mechanism effect in these resonators originates from...

We demonstrate experimentally Fano resonances in all-dielectric oligomers clusters of dielectric particles. study two structures consisting a ring six ceramic spheres with and without central particle that both exhibit resonant suppression the forward scattering associated resonance originated from excitation magnetic dipole modes. By employing near-field measurement techniques, we establish relation between near- far-field properties identify directly their origin. support our findings by...

The successful fabrication and experimental verification of a novel metamaterial based on flexible metallic helices is reported. undergo compression under the influence incident radiation, demonstrating nonlinear chiral electromagnetic response, associated with power-dependent change in helix pitch. This design promising for application to polarization rotation propagating waves. After decade fruitful development, metamaterials have received new momentum introduction alternative sources...

The concepts of many optical devices are based on fundamental physical phenomena such as resonances. One the commonly used is an electromagnetic antenna that converts localized energy into freely propagating radiation and vise versa, offering unique capabilities for controlling radiation. Here we propose a concept intensity directionality wave scattering in radio-frequency antennas physics Fano We develop analytical theory spatial resonances describes switching pattern between forward...

Abstract Photonic structures offer unique opportunities for controlling light‐matter interaction, including the photonic spin Hall effect associated with transverse spin‐dependent displacement of a light beam that propagates in specially designed optical media. However, due to small spin‐orbit coupling, is usually weak at nanoscale. Here we suggest theoretically and demonstrate experimentally, both optics microwave experiments, enhanced by topologically protected edge states subwavelength...

Magnetic resonance imaging (MRI) is one of the most important noninvasive techniques for human diagnostic medicine. Over decades MRI quality has improved substantially, through design very sensitive multichannel receivers, but designs based on conventional materials are nearly topped out in terms performance. Thus artificial sought to further boost sensitivity. The authors demonstrate a type metasurface that can dramatically enhance image quality, allowing resolution smaller features tumors,...