Effect of interfacial roughness on the phase of quantum well states in Cu/Co(001) and Cu/Ni(001) systems

It is known that the quantum well (QW) states in magnetic layered structures can be well described by a phase accumulation model (PAM) in which the phase is calculated by assuming a perfectly sharp interface. In order to verify the validity of this assumption, we studied the effect of interfacial mixing on the phase of QW states in Co/Cu/Co(001) and Co/Cu/Ni(001) systems. By controlling the annealing time, we progressively increased the interfacial mixing on these films. While the interlayer oscillatory coupling changes upon annealing, the coupling peak positions remain unchanged. This result suggests that the phase of the QW states have little dependence on the interfacial mixing.