Metamaterial approach is capable of drastically increasing the critical temperature, Tc, of composite metal-dielectric superconductors. Tripling of Tc was observed in bulk Al-Al2O3 core-shell metamaterials. A theoretical model based on the Maxwell-Garnett approximation provides a microscopic explanation of this effect in terms of electron-electron pairing mediated by a hybrid plasmon-phonon excitation. We report the first observation of this excitation in Al-Al2O3 core-shell metamaterials using inelastic neutron scattering. This result provides support for this novel mechanism of superconductivity in metamaterials and explains the 50 year old mystery of enhanced Tc in granular aluminium films.
@article{arxiv.1809.02715,
title = {Observation of plasmon-phonons in a metamaterial superconductor using inelastic neutron scattering},
author = {Vera N. Smolyaninova and Jeffrey W. Lynn and Nicholas P. Butch and Heather Chen-Mayer and Joseph C. Prestigiacomo and M. S. Osofsky and Igor I. Smolyaninov},
journal= {arXiv preprint arXiv:1809.02715},
year = {2019}
}
Comments
25 pages, 6 figures, this version is accepted for publication in Phys.Rev.B