MEISSNER EFFECT IN NORMAL-SUPERCONDUCTING PROXIMITY-CONTACT DOUBLE-LAYERS

The Meissner effect in normal-superconducting proximity-contact double layers is discussed in the clean limit. The diamagnetic current is ca lculated using the quasi-classical Green's function. We obtain the qua si-classical Green's function linear in the vector potential in the pr oximity-contact double layers with a finite reflection coefficient at the interface. It is found that the diamagnetic current in the clean n ormal layer is constant in space, therefore, the magnetic field linear ly decreases in the clean normal layer. We give an explicit expression for the screening length in the clean normal layer and study its temp erature dependence. We show that the temperature dependence in the cle an normal layer is considerably different from that in the dirty norma l layer and agrees with a recent experiment in Au-Nb system.