ON SMALL PERTURBATIONS OF STATIONARY STATES IN A NONLINEAR NONLOCAL MODEL OF A JOSEPHSON-JUNCTION

The problem of weak perturbations of steady states in a Josephson junction is considered in the strong coupling limit, when the Josephson length lambda(J) is smaller than the London depth lambda(L). This problem reduces to a nonlocal eigenvalue problem with periodic or localized potential. An infinite set of eigenfrequencies and corresponding eigenmodes of perturbations is found in explicit form for two different kinds of steady-state periodic structures and for a localized formation, corresponding to an isolated magnetic Josephson vortex.