We report magnetoresistance measurements through Nb films having a periodic thickness modulation. The cylinder shaped large-thickness 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 vs 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).
@article{arxiv.1208.4820,
title = {Vortex kinks in superconducting films with periodically modulated thickness},
author = {Jorge I. Facio and Anabella Abate and J. Guimpel and Pablo S. Cornaglia},
journal= {arXiv preprint arXiv:1208.4820},
year = {2015}
}