Influence of Quantum Size Effect and Interface Roughness on the Giant Magnetoresistance in Ultrathin Magnetic Layered Structures

In-plane electronic transport in ultrathin structures composed of two ferromagnetic films separated by a nonmagnetic metallic spacer is analysed theoretically. It is shown that quantum size effects give rise to oscillations in the dependence of the resistivity and giant magnetoresistance on the spacer thickness. It is also shown that the spin-dependent scattering due to interface roughness can enhance or compensate the magnetoresistance effect generated by the spin-dependent bulk scattering.