We present theoretical studies of the size dependence of the current perpendicular-to-the-plane ballistic conductance and giant magnetoresistance (GMR) in Fe/Cr and Co/Cu nanowires within a realistic tight-binding model. Symmetry properties of the nanowire with respect to transformations of the point group $C_{4v}$ are exploited to decompose the problem into several independent parts. This allows us to study mesoscopic-size nanowires which are experimentally achievable. Our calculations predict substantial reduction in GMR due to the finite size of the nanowire.

• Received 1 October 2002

DOI:https://doi.org/10.1103/PhysRevB.67.144425