Electromagnetic excitation of weakly damped collective oscillations in superconductors
Abstract
The excitation mechanism of longitudinal collective oscillations in a superconductor, due to relaxation of a nonequilibrium charge induced by an electromagnetic wave incident on its surface, is considered theoretically. The electric field distribution inside the superconductor and its relation with the field amplitude in vacuum are found. The contribution of collective oscillations to the surface impedance of the superconductor and to the transparency of a superconducting film, associated with successive transformations of the electromagnetic wave in vacuum into collective oscillations in the superconductor, and vice versa, is calculated.