CURRENT STATUS OF OUR UNDERSTANDING OF MAGNETOTRANSPORT IN MAGNETIC MULTILAYERS

We review the current theoretical understanding of giant magnetoresist ance in magnetic multilayered structures. The active ingredients produ cing magnetoresistance for current in and perpendicular to the plane o f the layers are discussed, and the effect of superlattice band struct ure on transport is reviewed. Differences between ballistic and diffus ive electron transport are highlighted. The effective fields used to a ccount for vertex corrections for current perpendicular to the layers is discussed and their meaning is defined.