Anomalous proximity effect in superconducting oxide structures with an antiferromagnetic layer

The electrophysical parameters of superconductor/antiferromagnetic insulator structures based on the Nb/Au/Ca1−xSrxCuO2/YBa2Cu3O7−δ hybrid heterostructure have been examined. YBa2Cu3O7−δ and Ca1−xSrxSuO2 epitaxial films are grown by the laser ablation method on NdGaO3 single crystal substrates, the thickness of the Ca1−xSrxCuO2 layer varies from 20 to 50 nm, and x = 0.15 and 0.5. The superconducting pair potential in the interface between the YBa2Cu3O7−δ superconductor and Ca1−xSrxCuO2 antiferromagnet is found to penetrate into the antiferromagnet at distances much larger than the coherence length calculated for the ferromagnetic layer. The critical current of the superconducting transition manufactured at such an interface is highly sensitive to the magnetic field.