Hybrid heterostructures with superconducting/antiferromagnetic interfaces

TL;DR

This study investigates hybrid superconducting heterostructures with a cuprate antiferromagnetic interlayer, revealing charge doping effects and interface properties crucial for understanding their electronic behavior.

Contribution

It provides detailed structural and electronic analysis of YBCO/CSCO/Nb heterostructures, highlighting charge doping during epitaxial growth and interface contributions to resistance.

Findings

Charge doping occurs in the CSCO interlayer during growth.

The doped CSCO layer exhibits metallic conductivity.

The Au/CSCO interface significantly influences the heterostructure's resistance.

Abstract

We report on structural, DC, X-ray and neutron studies of hybrid superconducting mesa-heterostructures with a cuprate antiferromagnetic interlayer Ca1-xSrxCuO2 (CSCO). The upper electrode was bilayer Nb/Au superconductor and copper oxide superconductor YBa2Cu3O7 (YBCO) was the bottom electrode. It was experimentally shown that during the epitaxial growth of the two films YBCO and CSCO a charge carrier doping takes place in the CSCO interlayer with a depth about 20 nm. The conductivity of the doped part of CSCO layer is close to the metal type, while the reference CSCO film, deposited directly on NdGaO3 substrate, behaves as Mott insulator with the hopping conductivity. The interface Au/CSCO is clearly seen on bright-field image of the cross-section of heterostructure and gives the main contribution to the total resistance of mesa-heterostructure.