Controlling jaggedness of magnetic domains with linear defects

Abstract Thin magnetic films with the out-of-plane anisotropy are more robust against thermal flips of nanosized domains than the in-plane spin geometry, and thus promising for ultra-high-density magnetic recording. However, dense packing of the small bits is limited by the domain wall roughness. Here we demonstrate that a correlated (line) defect directs and deroughens a field-driven wall, bringing it to a halt in the defect's vicinity. Scaling analysis of reduced jaggedness points to a simple way to control nanodomains for recording media.