Editor's Summary

9 October 2008

Skin-deep superconductivity

High-temperature interface superconductivity, confined to nanometre-size interfaces between two non-superconducting materials, has been long sought-after. Theorists speculated about it for forty years, but it has been elusive because of extreme demands on interface perfection and materials parameters. Gozar et al. now report the discovery of interface superconductivity between two non-superconducting cuprates — an insulator (La2CuO4) and a metal (La1.55Sr0.45CuO4). The critical tempeature (Tc) in bilayers is about 15 K or 30 K, depending on the layering sequence. This highly robust phenomenon is confined to within 2 or 3 nanometres of the interface, and if the bilayer is exposed to ozone, Tc rises to over 50 K.

LetterHigh-temperature interface superconductivity between metallic and insulating copper oxides

A. Gozar, G. Logvenov, L. Fitting Kourkoutis, A. T. Bollinger, L. A. Giannuzzi, D. A. Muller & I. Bozovic