DIAMAGNETIC RESPONSE OF NORMAL-METAL-SUPERCONDUCTOR DOUBLE-LAYERS

The magnetic response of a proximity-coupled superconductor-normal-met al sandwich is studied within the framework of the quasiclassical theo ry. The magnetization is evaluated for finite values of the applied ma gnetic field (linear and nonlinear response) at arbitrary temperatures and is used to fit recent experimental low-temperature data. The hyst eretic behavior predicted from a Ginzburg-Landau approach and observed in experiments is obtained within the quasiclassical theory and shown to exist also outside the Ginzbug-Landau region.