LONG JOSEPHSON-JUNCTIONS WITH UNIFORM DC AND RF DRIVING CURRENTS - GENERAL RESULTS FOR THE PHASE-LOCKED REGIMES

We investigate the dynamics of a long overlap Josephson junction in the presence of constant and sinusoidally time-varying currents on a finite-length spatial interval imposing open circuit boundary conditions at the ends. We scan the behavior of the system in parameter plane regions where the phase locking between the fluxon oscillations in the junction and the external time-varying field is possible. This scanning is performed for different values of the dc driving term and for lengths of the spatial interval ranging from 3.8 up to 15 and dissipation parameters ranging from 0.025 to 0.25. In spite of the complexity of the system and of the broad range of parameters investigated we find that the response to the rf excitation presents general features that can be well understood in terms of current-voltage characteristics of the junctions (and related experimental parameters). The results are compared with a recent theoretical model based on a perturbation approach of the sine-Gordon Hamiltonian.