and NbTiN-based hyperbolic metamaterial superconductors*

Recent experiments have demonstrated that the metamaterial dielectric function engineering is capable of enhancing superconducting properties, such as tripling the critical temperature T_c in Al-Al₂O₃ epsilon near zero (ENZ) core-shell metamaterial superconductors. Similar effects have been observed in hyperbolic (superconductor/dielectric) metamaterials. In order to expand this approach to superconductors with higher T_c, MgB₂/MgO, MgB₂/AlN, and NbTiN/AlN multilayers were fabricated. Dielectric constants of these metamaterials measured via polarization reflectometry will be reported. Correlation of the results of the transport measurements and the hyperbolic properties of the multilayers will be discussed.
[1] Vera N. Smolyaninova, et al., Sci. Rep. 6, 34140