Interlayer exchange coupling in magnetic multilayers with misaligned Fermi surfaces

We investigate the magnetic-layer thickness dependence of the interlayer exchange coupling in magnetic multilayers in which the extremal points of the Fermi surfaces for the spacer and magnetic material do not coincide. Deriving an asymptotic expression, we show that the oscillation period is determined by a stationary condition that depends on the mixed geometry of Fermi surfaces for both materials. A simple model calculation is performed to demonstrate this behavior. The implication of our study to realistic systems is discussed.