GINZBURG-LANDAU MODELIZATION OF SUPERCONDUCTING MULTILAYERS WITH PROXIMITY EFFECT

A phenomenological modelisation of superlattices made of alternating s uperconducting (S) and normal (N) layers coupled by proximity effect i s presented. It is shown that the anisotropy of such superconductors i s not a universal quantity but depends on external parameters such as temperature and applied magnetic fields. We also show that due to the destruction of the proximity effect in th N layers under high magnetic fields, the ratio H-c2(parallel to)/H-c2(perpendicular to) is general ly different from the anisotropy measured at low fields.