NONLINEAR PROPERTIES AND CRITICAL PARAMET ERS OF SUPERCONDUCTING FILMS IN THE REGIME WITH A GIVEN HIGH-FREQUENCY VOLTAGE

The nonlinear dynamics of the order parameter in a narrow superconduct ing channel exposed to high-frequency radiation with a given electric field strength is investigated theoretically. The frequency dependenci es of the critical transport current and high-frequency power, as well as the dependencies of critical current on electric field amplitude a nd the nonlinear absorption of electromagnetic wave in the superconduc tor are calculated. These dependencies display a strong frequency disp ersion near the relaxation frequencies of the order parameter and the quasi-particle distribution and agree well with experimental data. Som e effects specific to the regime with a given voltage are predicted.