Flux-line shear through narrow constraints in superconducting films

Abstract

Flux-line-lattice flow has been studied in a novel superconducting device containing straight, nanometer-scale, weak-pinning channels in a strong-pinning environment. The shear strength of a two-dimensional, triangular lattice has been directly probed on length scales of order of the lattice parameter by variation of the magnetic field. Good agreement is found with a continuum-approximation model for shear flow. Unusual oscillations in shear strength and history effects were observed and explained by the (in)commensurability between flux-line lattice and channel.