An intermittency caused by kink-antikink interaction in a perturbed sine-Gordon equation system

Kink-antikink interaction is numerically studied in a system of a perturbed sine-Gordon equation. We study a system in which a kink and an antikink are localized by placing two impurities between them. The kink and the antikink oscillate chaotically near the impurities by applying the external force. We observe kink-antikink motion with changing the strength of coupling, where the strength of coupling can be changed by changing the distance between two impurities. Time series of the distance between two kinks shows similar characteristics to that in the coupled chaotic oscillator system. An intermittency caused by chaos-chaos interaction is also observed. Power spectrum of this intermittency is a type of 1/f.