Nonlinear interaction of an electromagnetic wave and a dc current in a metallic film

The nonlinear interaction of a dc current flowing in a thin metal film with an electromagnetic wave illuminating the sample in a symmetric manner with respect to the magnetic field is investigated theoretically. The nonlinear ity is due to the most typical mechanism for pure metals at low temperature s - the magnetodynamic mechanism, involving the effect of the magnetic fiel d of the current and wave field on the electron trajectories. It is shown t hat this interaction leads to sharp kinks in the time dependence of the ele ctric field of the wave at the surface of the sample and to a peculiar elec tromagnetic signal amplification effect. (C) 2000 American Institute of Phy sics. [S1063-777X(00)01001-X].