By integrating a set of model equations for Josephson ladder subjected to a uniform transverse bias current we have found almost all of the kinds of breathers described in recent experiments, and closely reproduced their voltage-current characteristics and switching behaviour. Our main result is that a chaotic transient occurs in the switching process. The growth of tiny perturbations during the chaotic transient causes the new breather configuration to be extremely sensitive to the precise history of the initial breather and can also cause the new breather to have a new centre of symmetry.
This is a pre-print. It is also available at: http://arxiv.org/abs/cond-mat/0101439.