Coherent spin-polarized transport in ferromagnet/iron-pnictide-superconductor/ferromagnet structures

In the present paper, the Blonder-Tinkham-Klapwijk approach is used to study the effects of barrier strength Z and spin polarization P on coherent spin-polarized transport in ferromagnet (FM)/iron-pnictide-superconductor/FM structures. For comparison, the results for FM/SC/FM junctions without antiphase s-wave pairing or with s₊₊ model including the conventional s-wave state are also presented. It is demonstrated that the effects of Z and P on the particular features of oscillations of all the reflection and transmission probabilities, and differential conductances for the s_± -wave state in the junctions with energy E in ferromagnetic (F) and antiferromagnetic (AF) alignments of the magnetizations of the two ferromagnets are quite different, which are also different from those for the s₊₊ model.