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Title: High- T c superconductivity at the interface between the CaCuO 2 and SrTiO 3 insulating oxides

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 T c. We report the occurrence of high T c superconductivity in the bilayer CaCuO 2/SrTiO 3, where both the constituent oxides are insulating. In order to obtain a superconducting state, the CaCuO 2/SrTiO 3 interface must be realized between the Ca plane of CaCuO 2 and the TiO 2 plane of SrTiO 3. Only in this case can oxygen ions be incorporated in the interface Ca plane, acting as apical oxygen for Cu and providing holes to the CuO 2 planes. In addition, a detailed hole doping spatial profile can be obtained by scanning transmission electron microscopy and electron-energy-loss spectroscopy at the O K edge, clearly showing that the (super)conductivity is confined to about 1–2 CaCuO 2 unit cells close to the interface with SrTiO 3. The results obtained for the CaCuO 2/SrTiO 3 interface can be extended to multilayered high T c cuprates, contributing to explaining the dependence of T c on the numbermore » of CuO 2 planes in these systems.« less
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [1]
  1. Univ. di Roma Tor Vergata, Roma (Italy)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Univ. di Roma Tor Vergata, Roma (Italy); Univ. degli studi Niccolo Cusano, Roma (Italy)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 115; Journal Issue: 14; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY
OSTI Identifier:
1225418
Alternate Identifier(s):
OSTI ID: 1222044