Generation and Propagation of Fractional Fluxons in Josephson Media

We consider the problems related to the use of 0–π junctions with a nontrivial current–phase relation in Josephson transmission lines. The various types of excitations (fractional fluxons) propagating in such Josephson media have been studied. We have investigated the problem of the integration of Josephson transmission lines consisting of 0–π junctions (nontrivial Josephson transmission lines) with ordinary rapid single-flux-quantum electronics. We have analyzed the characteristic excitation transformation processes at the interfaces of ordinary and nontrivial Josephson transmission lines, which are largely similar to the Andreev reflections from a superconductor–normal metal interface.