Point Contact Spectra on YBa${}_2$Cu${}_3$O${}_{7-x}$/La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$ bilayers

We present conductance characteristics of point contact junctions realized between a normal Pt-Ir tip and YBa${}_2$Cu${}_3$O${}_{7-x}$/La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$ (YBCO/LCMO) bilayers. The point contact characteristics show a zero bias conductance peak, as a consequence of the formation of Andreev bound states at the YBCO Fermi level. The temperature evolution of the spectra reveals a depressed zero bias peak and a reduced superconducting energy gap, both explainable in terms of spin polarization effects due to the LCMO layer.