Novel reentrant effect in the proximity-induced superconducting behavior of silver

Abstract
A new reentrant behavior of the ac susceptibility in proximity-induced superconductivity of silver has been discovered. This is observed when the induced coherence length becomes comparable to the size of the specimen. The effect is destroyed by applying a magnetic field or by raising the temperature. This phenomenon points to the existence of a new form of quantum coherence effect in clean proximity-induced superconductors.