Energy-gap enhancement in superconducting tin by microwaves

Abstract
The energy gap in tin has been measured by observing the subharmonic gap structure in the current-voltage characteristics of a microbridge. The microbridge was irradiated with microwaves and the enhancement of the energy gap was compared to the predictions of the Eliashberg theory. At low power levels the agreement between theory and experiment is good but there is a large deviation at high power levels.