Multiphoton Process Observed in the Interaction of Microwave Fields with the Tunneling between Superconductor Films

Publisher Website
Google Scholar
Abstract
Calculations are made which explain qualitatively the multiphoton-assisted electron tunneling recently observed in superconducting diodes by Dayem and Martin. It seems to us that the microwave field is much too weak to cause any nonlinearities in the conduction current in the superconductors. Thus, the interaction does not cause transitions between electron states with different wave numbers. Rather, the energies of the electrons are varied adiabatically by the microwave fields. This gives rise to effective changes in the density of states versus energy which are dramatically illustrated in the tunneling current.