CALCULATION OF GIANT MAGNETORESISTANCE IN LATERALLY CONFINED MULTILAYERS IN THE CURRENT-IN-PLANE GEOMETRY

Wa have studied the giant magnetoresistance (GMR) for laterally confin ed multilayers, e.g., layers of wires, using the classical Boltzmann e quation in the current-in-plane geometry. For spin-independent specula rity factors at the sides of the wires we find that the GMR due to bul k and surface scattering decreases with lateral confinement. The lengt h scale at which this occurs is of the order of the film thickness and the mean free paths. The precise prefactor depends on the relative im portance of surface and bulk scattering anisotropies. For spin-depende nt specularity factors at the sides of the wires the GMR can increase in some cases with decreasing width. The origin of the change in the G MR in both cases can be understood in terms of lateral confinement cha nging the effective mean free paths within the layers.