Nonlinear behavior of a superconductor in an electromagnetic field

Abstract

It will be shown in this paper that it is possible to use a simpler equation than the Gor'kov-Bogolyubov equation for the description of the behavior of a superconductor in an electromagnetic field in the BKSh model far from the critical temperature T_c. An “exact” solution of this equation has been found for fields that vary in space. The possibility of using perturbation theory for the solution of this problem is analyzed. It turns out that this possibility is generally absent at frequencies ω lying in the shf region and lower, even in the case of comparatively low powers. The problem of the nonlinear behavior of a superconductor in an electromagnetic field is of appreciable theoretical and practical interest. However, as far as the author knows, only individual mechanisms [1, 2] that lead to appreciable nonlinearities have been discussed up to now. In contrast to the indicated papers, a scheme is developed in this paper that permits considering this problem for a London superconductor in the general form. A conclusion is drawn about the conditions necessary for the solution of this problem according to perturbation theory [3] on the basis of an analysis of the solution of the equation derived.