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Metasurfaces is a rapidly developing area with quite many prospective applications in light manipulation, aberration-free optical imaging, and security. One potential area where metasurface approaches may provide a valuable contribution is medical imaging. In this paper, a novel subwavelength metasurface-inspired resonator design is presented, which is employed to enhance the sensitivity of magnetic resonance imaging (MRI). To this end, the resonator is formed by an array of capacitively loaded telescopic wires is placed inside the scanner in a close proximity of the studied object. The telescopic design of the structure permits to mechanically adjust its eigenmode resonance frequency to the operational frequency of a 1.5T MRI machine, thus making it possible to enhance and redistribute the radiofrequency magnetic field of an available radiofrequency coil in the region of interest and therefore significantly increase the sensitivity of the receiver. [ABSTRACT FROM AUTHOR]

Employing nonlocal homogenization approach, we investigate the properties of a metamaterial consisting of parallel metallic wires with dielectric coating. We demonstrate that manipulation of dielectric contrast between wire dielectric shell and host material at fixed frequency results in dynamic switching of metamaterial dispersion regime from elliptic to the hyperbolic one, i.e. the topological transition takes place. It is proved that such transition can be induced by the variation of the metamaterial temperature. Our findings thus pave a way to the implementation of a tunable 'elliptic-hyperbolic' metamaterial. [ABSTRACT FROM AUTHOR]

Photonic structures offer unique opportunities for controlling light-matter interaction, including the photonic spin Hall effect associated with the transverse spin-dependent displacement of a light beam that propagates in specially designed optical media. However, due to small spin-orbit coupling, the photonic spin Hall effect is usually weak at the nanoscale. Here we suggest theoretically and demonstrate experimentally, in both optics and microwave experiments, the photonic spin Hall effect enhanced by topologically protected edge states in subwavelength arrays of resonant dielectric particles. Based on direct near-field measurements, we observe the selective excitation of the topological edge states controlled by the handedness of the incident light. Additionally, we reveal the main requirements to the symmetry of photonic structures to achieve the topology-enhanced spin Hall effect, and also analyse the robustness of the photonic edge states against the long-range coupling. [ABSTRACT FROM AUTHOR]

No abstract is available for this article. [ABSTRACT FROM AUTHOR]