A superlattice effect in the resistivity of multilayers

Calculations are presented of a superlattice effect, observable in samples where most of the scattering is at sharp interfaces. As the layer thicknesses change, oscillations in the resistivity of up to 100% are found. These oscillations are due to interface disorder breaking the degeneracy of certain states, causing them to have nodes at the interfaces. The states with nodes have high conductivities, leading to a “short-circuit” effect. Only for special thicknesses is it possible for a state to have nodes at all the interfaces. Hence, the oscillations occur as a function of layer thickness. Spreading the width of the interfaces or increasing the ratio of bulk disorder to interface disorder reduces the effect