Conductance Oscillations in transition metal superlattices

S. Sanvito, C.J. Lambert, J.H. Jefferson, and A.M. Bratkovsky

We present a numerical study of conductance oscillations of transition metal multilayers as a function of layer thickness. Using a realistic material-specific tight-binding model, we show that for disorder-free layers with random thicknesses but clean interfaces, long-period oscillations in the conductance can occur, which are reminiscent of those found in structures exhibiting GMR. Using a heuristic effective mass model, we argue that these oscillations arise from beating between the Fermi wavevector and a class of wavevectors characteristic of the superlattice structure.