BREATHER DECOMPOSITION INTO FLUXON ANTIFLUXON PAIR ON A DRIVEN LONG JOSEPHSON-JUNCTION WITH A LOCAL IMPURITY

Breathers excitations in a driven long Josephson junction influenced by a localized impurity due to a spatial variation of the inductance are discussed. By use of the perturbation method, it is shown that, in the absence of the bias current, the breather can break into a fluxon-antifluxon pair (ffBAR), for values of the inductance greater than a threshold value (l(othr)). It is also seen that when the bias current is greater than a threshold value (eta(thr,lo)), the breather can convert into a ffBAR for every value of the inductance. An approximate frequency for the breather is calculated in this framework.