Pinning of fluxons by structure of Abrikosov vortices in long Josephson tunnel junction

The influence of Abrikosov vortices (A-vortices) on the dynamics of fluxons (Josephson vortices) in Nb-AlO/sub x/Nb long Josephson tunnel junctions (LJTJs) has been investigated experimentally. Trapping of Abrikosov vortices was obtained by cooling of the junction through the superconducting transition temperature in magnetic fields applied perpendicularly to the plane of the junction (H/sub perpendicular to /). The dependences of the Josephson critical current on an external magnetic field applied parallel to the plane of the junction were measured after cooling at different values of H/sub perpendicular to /. Changes of both the maximum Josephson critical current and the critical magnetic field of LJTJ H/sub c1/ have been observed for an LJTJ with an irregular structure of A-vortices trapped in the electrodes of the junction. The effects are explained by the pinning of Josephson vortices at the effective misaligned A-vortices.<
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