Point contact spectroscopy of the electron-doped cuprate superconductor Pr{2-x}Ce{x}CuO4: The dependence of conductance-voltage spectra on cerium doping, barrier strength and magnetic field

We present conductance-voltage (G-V) data for point contact junctions between a normal metal and the electron doped cuprate superconductor Pr{2-x}Ce{x}CuO4 (PCCO). We observe a zero bias conductance peak (ZBCP) for the under-doped composition of this cuprate (x=0.13) which is consistent with d-wave pairing symmetry. For optimally-doped (x=0.15) and over-doped (x=0.17) PCCO, we find that the G-V characteristics indicate the presence of an order parameter without nodes. We investigate this further by obtaining point contact spectroscopy data for different barrier strengths and as a function of magnetic field.