Observation of a fluxon-antifluxon collision in a Josephson transmission line

The behavior of a fluxon-antifluxon collision in a Josephson transmission line is experimentally investigated, with use of a direct measurement system for a fluxon waveform. The experiment shows an increase in propagation delay time following a collision. This result can be qualitatively explained as the effect of dissipative perturbation by using a numerical simulation and perturbation theory, where the origin of the increase in the delay time is explained in terms of a power balance equation. The effect of nonuniformity in the transmission line parameters on a collision is evaluated to account for the observed spatial distribution of delay-time increase. Analysis with a -function-like defect shows that there is evidence of such a defect in the experimental data.