Derev'yanko S. The nonlinear interaction of electromagnetic waves in normal metals and hard superconductors

Objects: specific nonlinearity of normal metals and hard superconductors in the critical state. Goals: investigate theoretically the nonlinear interaction of radiowaves. Methods: analytical and numerical integration of nonlinear electrodynamical equations with the magnetic field dependent conductivity operator (normal metals) and with nonlinear material equation (hard superconductors). New results: Determined the nonanalytical behaviour as well as an effect of amplification of the temporal dependence of the surface electric field in a metal plate carrying a DC current. Predicted a new phenomenon of the nonmonotonic dependence of the impedance of a metal film on the amplitude of an AC current due to its interaction with a DC component. A novel effect of the stimulated trans-parency of a superconducting plate due to the nonlinear wave interaction is also predicted.