Enhanced fluxon transmission through impurities

Fluxon transmission through several impurities of different strength and type (i.e., microshorts and microresistors), placed in a long Josephson junction is investigated. Threshold pinning current on the impurities is computed as a function of the distance between them, their amplitudes and the dissipation parameter. It is shown that in the case of consequently placed microshorts or microresistors, the threshold pinning current exhibits a clear minimum as a function of the distance between the impurities. In the case of a microresistor, followed by a microshort, an opposite phenomenon is observed, namely the threshold pinning current exhibits maximum as a function of the distance between the impurities.