SYNCHRONIZATION AND PHASE-LOCKING IN 2-DIMENSIONAL ARRAYS OF JOSEPHSON-JUNCTIONS

We report numerical studies of phase locking in two-dimensional (2D) a rrays of Josephson junctions. In the conventional 2D arrays biased wit h de current in the horizontal (X) direction, the phase-locked solutio n is only possible in arrays with no disorder. In the presence of diso rder in the junction critical currents, we see vertical (Y) columns of phase locked clusters form in the array with no intercolumn locking. As an extension, we introduced a geometry called XY-biased array, wher e the array is biased in both X and Y directions. In XY-biased array w e found a dynamical state, where all junction voltages are strictly de and the only oscillating components are the supercurrents in each jun ction. This dynamical state is stable against experimentally achievabl e disorder in the junction critical currents.