Influence of macroscopic magnetic inhomogeneity on the superconducting proximity effect in MgB2/La2/3Ca1/3MnO3 nanocomposite

Abstract

As theory predicts, long-extended triplet superconducting correlations are realized in superconductor/ferromagnet (SC/F) structures in the presence of magnetization inhomogeneity at the SC–F interface. In this report, the external magnetic field effect on triplet superconducting correlations in the nanocomposite of proximity coupled s-wave SC, MgB2, and half-metallic ferromagnet (hmF), La2/3Ca1/3MnO3, has been investigated experimentally. The results obtained bring out clearly that the nanocomposite’s superconducting characteristics significantly correlate with the La2/3Ca1/3MnO3 nanoparticles bulk magnetization order. In particular, the dependence of the point contacts’ conductance characteristics on the external magnetic field demonstrates direct spectroscopic signatures that the nanoscale magnetization inhomogeneity plays an essential role in the generation of a long-extended triplet superconductivity in SC/hmF proximity coupled nanostructures. The results obtained prove the impact of nanoscale magnetic nonhomogeneity on the generation of the spin-triplet Cooper pairing in SC/hmF structures.