Second harmonic generation study of quantum well states and interdiffusion in a Co/Rh multilayer

The nonlinear optical response of a Rh overlayer on top of a Co film shows an oscillatory behaviour as a function of Rh thickness. The oscillation period is the same as for the the period of the oscillatory exchange coupling of two Co layers separated by a Rh wedge. Spectroscopic studies show that the period and the phase are independent of the wavelength. The observed strong temperature dependence of the nonlinear response can be related to the interdiffusion of Rh in Co.