Nonlinear interaction of an electromagnetic wave with a direct current in a metal film

The nonlinear interaction between direct electric current flowing in a thin metal film and external electromagnetic wave, irradiating the sample symmetrically with respect to magnetic field is theoretically studied. The nonlinearity is related to the influence of the magnetic field of direct current and the magnetic field of the wave on electron trajectories. This magnetodynamic mechanism, as it is called, is most typical of pure metals at low temperatures. It is shown that this interaction gives rise to sharp kinks in the temporal dependence of the electric field of the wave on the sample surface. An effect of amplification of the electromagnetic signal on the metal surface is also predicted.