Breakdown of the resistor model of CPP-GMR in magnetic multilayered nanostructures

We study the effect on CPP GMR of changing the order of the layers in a mul tilayer. Using a tight-binding simple cubic two band model (s-d), magneto-t ransport properties are calculated in the zero-temperature, zero-bias limit , within the Landauer-Buttiker formalism. We demonstrate that for layers of different thicknesses formed from a single magnetic metal and multilayers formed from two magnetic metals, the GMR ratio and its dependence on disord er is sensitive to the order of the layers. This effect disappears in the l imit of large disorder, where the results of the widely-used Boltzmann appr oach to transport are restored.