title: Vortex kinks in superconducting films with periodically modulated thickness.
abstract: We report magnetoresistance measurements in Nb films having a periodic thickness modulation. The cylinder shaped thicker regions of the sample, which form a square lattice, act as repulsive centers for the superconducting vortices. For low driving currents along one of the axes of the square lattice, the resistivity ρ increases monotonously with increasing magnetic field B and the ρ-B characteristics are approximately piecewise linear. The linear ρ versus B segments change their slope at matching fields where the number of vortices is an integer or a half integer times the number of protruding cylinders in the sample. Numerical simulations allow us to associate the different segments of linear magnetoresistance to different vortex-flow regimes, some of which are dominated by the propagation of discommensurations (kinks).
authors.affiliation: Instituto Balseiro, Comisión Nacional de Energía Atómica and Universidad Nacional de Cuyo, Centro Atómico Bariloche, 8400 Bariloche, Argentina. facioj@ib.cnea.gov.ar
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Facio
authors.forename: Anabella
authors.initials: A
authors.lastname: Abate
authors.forename: J
authors.initials: J
authors.lastname: Guimpel
authors.forename: Pablo S
authors.initials: PS
authors.lastname: Cornaglia