Several configurations of YBa2Cu3Ox(YBCO)-based Josephson junctions have been experimentally investigated. For symmetric 45° grain boundary Josephson junctions was found: (i) The critical current exhibits, as a function of temperature, a local minimum. (ii) The first harmonic of the current phase relationship I(φ) changes sign. For asymmetric 45° grain boundary junctions the current phase relation has been found to be close to sin(2φ). For Nb/Au/(0 0 1)YBCO heterojunctions formed along the c-axis, the finite amplitude of the second harmonic in the current phase relationship was found as well. The results are in good agreement with a microscopic model of Josephson junctions in the frame of the d-wave scenario. © 2002 Elsevier Science B.V. All rights reserved.
Il’Ichev, E. (2002). d-wave peculiarities of YBCO-based Josephson junctions. Physica C: Superconductivity and Its Applications, 367(1–4), 79–85. https://doi.org/10.1016/S0921-4534(01)01003-6