Electronic reconstruction and enhanced superconductivity at La1.6−xNd0.4SrxCuO4/La1.55Sr0.45CuO4 bilayer interface
1 Condensed Matter - Low Dimensional Systems Laboratory, Department of Physics, Indian Institute of Technology Kanpur - Kanpur-208016, India
2 National Physical Laboratory, Council of Scientific and Industrial Research - New Delhi-110012, India
Received: 8 April 2012
Accepted: 4 June 2012
We report enhanced superconductivity in bilayer thin films consisting of superconducting La1.6−xNd0.4SrxCuO4 with 0.06 ⩽ x < 0.20 and metallic but non-superconducting La1.55Sr0.45CuO4. These bilayers show a maximum increase in superconducting transition temperature (Tc) of more than 200% for x = 0.06, while no change in Tc is observed for the bilayers with x ⩾ 0.20. The analysis of the critical current and kinetic inductance data suggests 2–3 unit cells thick interfacial layer electronically perturbed to have a higher Tc. A simple charge transfer model with cation intermixing explains the observed Tc in bilayers. Still the unusually large thickness of interfacial superconducting layers cannot be explained in terms of this model. We believe that the stripe relaxation as well as the proximity effect also influence the superconductivity of the interface.
PACS: 74.72.Gh – Hole-doped / 73.40.-c – Electronic transport in interface structures / 75.70.-i – Magnetic properties of thin films, surfaces, and interfaces
© EPLA, 2012