Ferromagnetic insulator Josephson junctions consisting of Nb/Au/Pr0.8Ca0.2MnO3/La1.85Sr0.15CuO4 layers were fabricated. Non-linear current-voltage characteristics suggest the presence of superconducting coupling between the Nb/Au and La1.85Sr0.15CuO4 layers across a ferromagnetic Pr0.8Ca0.2MnO3 tunnel barrier. Tunneling spectra showed clear conductance peaks due to quasi-particle tunneling. Superconducting gap energies determined from the tunneling spectra were consistent with the temperature dependence of the critical current of the junctions. We argue that magnetic inhomogeneity in the ultrathin tunnel barrier plays a role in linking the superconducting states in Nb/Au and La1.85Sr0.15CuO4.
ASJC Scopus subject areas
- Physics and Astronomy(all)