Triplet superconducting proximity effect in nonhomogeneous magnetic materials

Abstract

We show that quantum spin fluctuations in inhomogeneous conducting ferromagnets

drastically affect the Andreev reflection of electrons and holes at a ferromagnet-

superconductor interface. As a result, a strong long-range proximity effect appears,

associated with electron-hole spin triplet correlations and persisting on a length scale

typical for nonmagnetic materials but anomalously large for ferromagnets. For applications,

an important consequence is that this long-range proximity effect permits to create

superconducting quantum intetference devices with the Josephson magnetic junction of an

anomalous large length.