1202.0165 (I. V. Bobkova et al.)

Long-range proximity effect for opposite-spin pairs in S/F
heterostructures under non-equilibrium quasiparticle distribution    [PDF]

I. V. Bobkova, A. M. Bobkov

By now it is known that in a singlet superconductor/ferromagnet (S/F)
structure the superconducting correlations carried by opposite-spin pairs
penetrate into the ferromagnet over a short distance of the order of magnetic
coherence length. The long-range proximity effect (LRPE), taking place on the
length scale of the normal metal coherence length, can only be maintained by
equal-spin pairs, which can be generated by magnetic inhomogeneities in the
system. In this work we have predicted a new type of LRPE, which can take place
in S/F heterostructures under non-equilibrium conditions. The superconducting
correlations in the F region are generated by opposite-spin Cooper pairs and
equal-spin pairs are not involved. The possibility for an opposite-spin pair to
penetrate into the ferromagnet over a large distance is provided by creation of
the proper non-equilibrium quasiparticle distribution there. This leads to a
sharp increase (up to a few orders of magnitude) of the critical Josephson
current through a S/F/S junction at some values of the voltage controlling the
nonequilibrium distribution in the F interlayer.

View original: http://arxiv.org/abs/1202.0165