Theoretical modeling of critical temperature increase in metamaterial superconductors

TL;DR

This paper presents a theoretical model explaining how metamaterials can significantly increase the critical temperature of superconductors, aligning well with experiments and predicting high Tc for new metamaterial designs.

Contribution

The paper introduces a Maxwell-Garnett based theoretical model for Tc enhancement in metamaterial superconductors, validated against experiments and used to predict high Tc in hypothetical materials.

Findings

Good agreement between theory and experiment for aluminium and tin metamaterials.

Predicted Tc of ~250K for H2S-based metamaterial superconductors.

Potential to reach liquid nitrogen temperatures with MgB2-based metamaterials.

Abstract

Recent experiments have demonstrated that the metamaterial approach is capable of drastic increase of the critical temperature Tc of epsilon near zero (ENZ) metamaterial superconductors. For example, tripling of the critical temperature has been observed in Al-Al2O3 ENZ core-shell metamaterials. Here, we perform theoretical modelling of Tc increase in metamaterial superconductors based on the Maxwell-Garnett approximation of their dielectric response function. Good agreement is demonstrated between theoretical modelling and experimental results in both aluminium and tin-based metamaterials. Taking advantage of the demonstrated success of this model, the critical temperature of hypothetic niobium, MgB2 and H2S-based metamaterial superconductors is evaluated. The MgB2-based metamaterial superconductors are projected to reach the liquid nitrogen temperature range. In the case of an H2S-based metamaterial Tc appears to reach ~250K.