ROLE OF BOUND-STATES OF MAGNETIC LAYERS IN THE THEORY OF MULTILAYER INTERACTION

Using planar Dirac delta functions to describe the coupling of magneti c layers to an electron gas, the interaction between the layers is cal culated. Both the bound and free states give contributions which are s haped by the range of the bound states. Due to a remarkable cancellati on of terms the combined result does not show this shape. In fact, it differs appreciably from the weak-coupling limit only when the binding energy of the bound states is comparable or larger than the Fermi ene rgy.