Transport properties of vortices in easy flow channels: A Frenkel-Kontorova study

Incommensurate easy flow channels in an otherwise perfect vortex lattice ar e investigated. The associated (point) defects in the lattice inside the ch annel cause an almost vanishing critical current, as shown by molecular dyn amics simulations and a comparison with the Frenkel-Kontorova model. In add ition to the normal flux flow behavior, we find a low mobility regime at sm all drives associated with defect motion. We treat this situation analytica lly for the case of a single defective vortex row. We also briefly discuss the relation to existing experiments on artificial vortex channels.