Linear and nonlinear excitations in two stacks of parallel arrays of long Josephson junctions

We investigate a structure consisting of two parallel arrays of long Joseph son junctions sharing a common electrode that allows inductive coupling bet ween the arrays. A model for this structure is derived starting from the de scription of its continuous limit. The excitation of linear cavity modes kn own from continuous and discrete systems as well as the excitation of a new state exhibiting synchronization in two dimensions are inferred from the m athematical model of the system. The stable nonlinear solution of the coupl ed sine-Gordon equations describing the system is found to consist of a flu xon-antifluxon string. This is a two-dimensional phase-locked solitonic mod e. Both linear and nonlinear excitations are numerically investigated and e xperimentally demonstrated in two stacks of five-junction arrays.