Triplet superconducting proximity effect in inhomogeneous magnetic materials

We show that quantum spin fluctuations in inhomogeneous conducting ferromag nets drastically affect the Andreev reflection of electrons and holes at a ferromagnet-superconductor interface. As a result, a strong long-range prox imity effect appears, associated with electron-hole spin triplet correlatio ns and persisting on a length scale typical for nonmagnetic materials but a nomalously large for ferromagnets. For applications, an important consequen ce is that this long-range proximity effect permits the creation of superco nducting quantum interference devices with magnetic Josephson junctions of anomalously large length. (C) 2001 American Institute of Physics.