Proximity effect and quasi-particle-lifetime effect in ferromagnet/f-wave superconductor junctions

Abstract

The proximity effect and finite-quasi-particle-lifetime effect in normal metal/insulator/ferromagnet/f-wave superconductor (NM/I/FM/f-wave SC) structures is theoretically investigated by an extended Blonder-Tinkham-Klapwijk approach. Two types of pairings for f-wave are chosen. It is found that due to the proximity effect whether in the case of f1-wave or f2-wave, the conductance spectra exhibit a transition from the “0 state” to “π state” with increasing the ferromagnetic exchange energy. Due to the essential difference between the two pairing potentials of f-wave, the tunneling conductance has a zero-bias peak in NM/I/FM/f1-wave SC junctions while two energy-gap peaks in NM/I/FM/f2-wave SC junctions. Shortening the lifetime of quasi-particle between collisions can suppress the proximity effect and prevent the formation of the Andreev bound states in the junction. These results can be used to determine the pairing symmetry of f-wave and distinguish f1 and f2-wave.