Effect of memory and dynamical chaos in long Josephson junctions

A long Josephson junction in a constant external magnetic field and in the presence of a dc bias current is investigated. It is shown that the system, simulated by the sine-Gorgon equation, “remembers” a rapidly damping initial perturbation and final asymptotic states are determined exactly with this perturbation. Numerical solving of the boundary sine-Gordon problem and calculations of Lyapunov indices show that this system has a memory even when it is in a state of dynamical chaos, i.e., dynamical chaos does not destroy initial information having a character of rapidly damping perturbation.