THE MAGNETIC-FIELD PENETRATION INTO A JOSEPHSON JUNCTION

The critical state of the linear inhomogeneous Josephson junction with the pinning centers distributed periodically is studied. The profiles of magnetic field penetration into the junction are plotted. The phase correlation in all points of the junction is taken into account by means of the numerical solution for the chain of the sine-Gordon equations involving the joining conditions for the pinning centers. If the interdefect distances and pinning forces are large enough, the dependences obtained are described approximately by the Bean phenomenological formula. For the opposite case, there are two possibilities, either the profile front is extended extremely or the homogeneous flux line distribution is realized immediately when the external field exceeds a definite value in the junction.