Peculiarity of non-equilibrium superconductivity in half-metallic ferromagnet/insulator/superconductor Co2CrAl/I/Pb heterostructures

The peculiarities of electron transport trough the tunnel half-metallic ferromagnet(Co2CrAl)/insulator/superconductor(Pb) (HMF/I/S) junctions have been investigated. It was experimentally shown that the effective life-time of the spin-polarized quasi-particles ensemble in superconductor before their recombination into singlet cooper pairs is much longer than that for non-polarized ones. It was also found that the tunnel injection of spin-polarized current from HMF into S in HMF/I/S junction in its superconductive state the effect of “giant blocking” of the tunnel current is appeared. In this case at bias voltage, Vt, close to zero a very significant increase in differential resistance of the HMF/I/S junction in comparison with that of the N/I/S one is observed (where N is normal metal). Additionally, it was also established that at Vt→0 the ratio of differential resistance in superconductive state to that of in the normal state for the Co2CrAl/I/Pb junction is much bigger than corresponding ratio for N/I/S junctions obtained experimentally as well as in the frame of Bardeen, Cooper and Schrieffer theory.