Nonlinear interaction of an electromagnetic wave with a transport current in a hard superconductor

It is predicted that the time dependence of the electric field at the surface of a superconducting slab carrying a transport current will have jumps that occur as a result of the interaction of the current with the field of the electromagnetic wave. A theoretical analysis of the phenomenon is carried out in a simple model for arbitrary monotonic dependence of the critical current density on the magnetic induction. The dependence of the value of the jump of the electric field on the amplitude of the wave and the strength of the transport current is investigated. The predicted effect can be observed experimentally by measuring the emf of a coil wound on the slab in the plane perpendicular to the external ac magnetic field.