Critical temperature enhancement in a composite superconductor" (Students Lectures):
Increasing superconductors' critical temperature has been a long standing goal in material science. In order to do so, both a high Cooper-pairing energy and a large phase coherence of the pairs are required. However, these two necessary ingredients tend to compete with each other. It has been suggested that it is possible to overcome this competition by coupling a superconductor to a metallic layer. We determine the optimal conditions for the enhancement within a model of such a composite system.