Magnetic field dependence of the critical current in long 'quasi-overlap' Josephson junctions

The effect of the magnetic field on the current distribution in one-dimensional long Josephson tunnel junctions is investigated. Overlap and mixed overlap/in-line configurations are considered. The latter geometry corresponds to an experimental situation, since it takes into account nonuniformities of the bias current. A simple method to investigate the dependence of the Josephson critical current on the external magnetic field for any junction length is developed. The predictions, based on the phase space analysis, are compared with experimental results obtained on long junctions of different lengths. The possibility of using this method to evaluate relevant junction parameters from the experimental measurements is discussed.