Effect of Structural Potential on Magnetic Vortex Solitons in Spatially 1D-Extended Josephson Junction

Soliton evolution in spatially extended Josephson junction is studied for three types of ad hoc structural potentials describing tunnelling magnetic flux vortices; symmetric, ratchet and double-well. Setting from the inline geometry of the junction, the soliton dynamics could be modelled by the perturbed sine-Gordon equation. Numerical solutions of the latter equation yielded the soliton waves of the fluxon phase, for boundary conditions imposed on the system upon variation of the dispersion parameter α. It has been found that a change in the soliton waveform and intensity occurs as α goes higher, in dependence on the functional of the potential and its symmetry properties. For ratchet and double-well potential at α=0.5, a time-dependent forcing has been found to endorse the balance between dispersion and nonlinearity, jointly with enhancing the stability of the soliton wave. The McLoughlin-Scott perturbation theory has been adopted to show that the system conserves energy due to the delicate balance between nonlinearity and dispersion, so that the soliton keeps robust as it temporally evolves.