INTERACTION OF ELECTROMAGNETIC-WAVES IN HARD SUPERCONDUCTORS

Nonlinear interaction of low-frequency radio-waves in hard superconductors is studied both theoretically and experimentally. It is shown that this interaction gives rise to a new nonlinear phenomenon, namely, jumps in the temporal dependence of the electric field at the surface of the sample. Heights and positions of the jumps are determined by the amplitudes, frequencies, and phase difference of the interacting waves. Necessary conditions for the existence of the jumps are discussed. The calculations are carried out in the framework of a critical-state model with an arbitrary magnetic field dependence of the critical current density. Experimental results are found in good agreement with theoretical ones.