Anomaly of zero-bias conductance peaks in ferromagnet/d-wave superconductor junctions - art. no. 144520

The Blonder-Tinkham-Klapwijk approach is applied to studying spin-polarized quasiparticle transport in ferromagnet (FM)/d-wave superconductor (SC) jun ctions by taking into account the roughness of the interfacial barrier, bro ken time-reversal symmetry (BTRS) states near the surface of the SC, and ex change interactions in the FM. It is shown that (1) the exchange splitting in the FM decreases the height of the zero-bias conductance peak (ZBCP) and may induce a zero-bias conductance dip (ZBCD), (2) the presence of the BTR S states in the SC may make the ZBCP split into two peaks, and (3) the inte rface roughness obstructs the ZBCP splitting and decreases the height of th e ZBCP. The calculated results can account for the ZBCD observed experiment ally in La2/3Ba1/3MnO3/DyBa2Cu3O7 and La2/3Ba1/3MnO3/YBa2Cu3O7-delta juncti ons.