Study of the pairing symmetry in the electron-doped cuprate Pr1-xLaCexCuO4-yPr1-xLaCexCuO4-y by tunneling spectroscopy

We performed Point Contact Andreev Reflection Spectroscopy experiments on Pr1-xLaCexCuO4-yPr1-xLaCexCuO4-y crystals. The variety of the measured spectra are all explained in terms of a modified BTK model considering a d-wave symmetry of the superconducting order parameter. We give an estimation of the energy gap Δ=(3.5±0.2)meV and of the ratio 2Δ/kBTC≃3.6±0.32Δ/kBTC≃3.6±0.3. We measured the temperature evolution of the dI/dVdI/dV vs. V characteristics and we extracted a conventional BCS temperature dependence of the superconducting energy gap. Finally, in order to explain the conductance spectra showing higher voltage gap-like features we consider a model in which the formation of a Josephson junction in series with the Point Contact junction is realized due to the tip pressure.