Negative dielectric constant and dominant kinetic resistance make superconductors an intriguing plasmonic media. Here we report on the first study of one of the most important and disputed manifestations of plasmonics, the effect of extraordinary transmission through an array of subwavelength holes, using a perforated film of high-temperature superconductor.The effect of extraordinary transmission can be regarded as one of the most important and disputable phenomenon in the area of plasmonics. It was observed as sharp peaks in transmission spectra of nondiffracting periodic arrays of sub-wavelength holes made in thin metal films [1]. The transmission efficiency at those maxima exceeded unity (when normalized to the area of the holes), which was orders of magnitude greater than predicted by standard aperture theory. Such unusual optical properties were attributed to resonant coupling of light with plasmons mediated by periodic patterning of the metal films.Superconductors can be regarded as media with negative real dielectric constant and mainly kinetic resistance, and therefore electromagnetics of such structures falls into the domain of plasmonics. Here we report the first experimental data on observation of extraordinary transmission in a perforated nondiffracting superconducting film and demonstrate that the magnitude of the extraordinary transmission resonances can be controlled with temperature and increases dramatically upon superconducting phase transition.Our experiments were performed using a free-space setup, which is based on mm-wave test system equipped with horn antennas and a closed-cycle liquid-helium cryostat, as shown in Fig. 1a and 1b. The superconduting film had the thickness of 300 nm and was made of high-temperature superconductor YBCO deposited on a low-loss sapphire substrate. It was perforated by etching an array of 1 mm holes with the period of 2.7 mm (see Fig. 1c), which rendered the structure non-diffracting at frequencies below 110 GHz. Transmission of the perforated cuprate film was measured for normal incidence

Nonlinear and switchable metamaterials achieved by artificial structuring on the subwavelength scale have become a central topic in photonics research. Switching with only a few quanta of excitation per metamolecule, metamaterial's elementary building block, is the ultimate goal, achieving which will open new opportunities for energy efficient signal handling and quantum information processing. Recently, arrays of Josephson junction devices have been proposed as a possible solution. However, they require extremely high levels of nanofabrication. Here we introduce a new quantum superconducting metamaterial which exploits the magnetic flux quantization for switching. It does not contain Josephson junctions, making it simple to fabricate and scale into large arrays. The metamaterial was manufactured from a high-temperature superconductor and characterized in the low intensity regime, providing the first observation of the quantum phenomenon of flux exclusion affecting the far-field electromagnetic properties of the metamaterial.

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Ar(+) ions have been implanted into Laves phase epitaxial thin films of YFe(2) and DyFe(2). Magneto-optical Kerr effect and vibrating sample magnetometry experiments show that the easy and hard axes of magnetization in both materials rotate through an in-plane angle of 90°, whilst the strength of the magnetic anisotropy remains unaltered. This is supported by OOMMF computational modelling. Atomic force microscopy confirms that the film roughness is not affected by implanted ions. X-ray diffraction data show that the lattice parameter expands upon ion implantation, corresponding to a release of strain throughout the entire film following implantation with a critical fluence of 10(17) Ar(+) ions cm(-2). The anisotropy of the films is linked to the strain and from these data it is concluded that the source of anisotropy alters from one where magnetoelastic and magnetocrystalline effects compete to one which is governed solely by magnetocrystalline effects. The ability to locally tune the source of magnetic anisotropy without affecting the film surface and without inducing or eliminating anisotropy could be important in the fabrication of high density magnetic data storage media, spintronic devices and magneto-optical materials.