SINGLE-VORTEX DYNAMICS IN OVERDAMPED JOSEPHSON-JUNCTION LADDERS

The single-vortex dynamics in ladders of overdamped Josephson junction s is investigated by means of numerical simulations. We derive the vel ocity (upsilon), the coefficient of viscosity (eta) and the height of the dynamical barrier for the cell-to-cell vortex motion (E(b)) as fun ctions of the bias current (i(dc)), the magnetic field penetration dep th (lambda(perpendicular to)) and the vortex position (x). The vortex dynamics can be satisfactorily described in terms of the motion of a p article subjected to a potential U(x, i(dc), lambda(perpendicular to)) , the form of which is analysed.