1. High Tc superconductivity at the interface between the CaCuO2 and SrTiO3 insulating oxides
- Author
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DI CASTRO, D, Cantoni, C, Ridolfi, F, Aruta, C, Tebano, A, Yang, N, and Balestrino, G
- Subjects
Electronic systems ,FOS: Physical sciences ,High resolution transmission electron microscopy ,Settore FIS/03 - Fisica della Materia ,Superconductivity (cond-mat.supr-con) ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,Electron energy levels ,Electron scattering ,Scanning transmission electron microscopy ,Electron energy loss spectroscopy ,Apical oxygen ,Calcium ,Electronic properties ,Energy dissipation ,Insulation ,Scanning electron microscopy ,Strontium titanates ,Transmission electron microscopy, Apical oxygen ,Complex oxides ,High-Tc cuprates ,High-Tc superconductivity ,Spatial profiles ,Superconducting state, Interface states ,Condensed Matter - Superconductivity ,Interface states ,Superconducting state ,Transmission electron microscopy - Abstract
At interfaces between complex oxides it is possible to generate electronic systems with unusual electronic properties, which are not present in the isolated oxides. One important example is the appearance of superconductivity at the interface between insulating oxides, although, until now, with very low Tc. We report the occurrence of high Tc superconductivity in the bilayer CaCuO2/SrTiO3, where both the constituent oxides are insulating. In order to obtain a superconducting state, the CaCuO2/SrTiO3 interface must be realized between the Ca plane of CaCuO2 and the TiO2 plane of SrTiO3. Only in this case extra oxygen ions can be incorporated in the interface Ca plane, acting as apical oxygen for Cu and providing holes to the CuO2 planes. A detailed hole doping spatial profile has been obtained by STEM/EELS at the O K-edge, clearly showing that the (super)conductivity is confined to about 1-2 CaCuO2 unit cells close to the interface with SrTiO3. The results obtained for the CaCuO2/SrTiO3 interface can be extended to multilayered high Tc cuprates, contributing to explain the dependence of Tc on the number of CuO2 planes in these systems., 14 pages, 4 figures
- Published
- 2016