Influence of asymmetry of Kerr signal on vortex configuration in submicro-scaled permalloy disc array

A self-alignment method for local coating fabrication in submicro-scaled discs is described. The adjustable area of the capping layer on the magnetic disc can create asymmetric Kerr signals for vortex configuration and provide different asymmetries of the Kerr signal. Nondegenerate Kerr signals of vortex chirality in 300 nm diameter and 40 nm thick Ni₈₀Fe₂₀ discs locally capped with 25 nm thickness Al were investigated. Various capping area ratios ranging from 0 to 0.5 were fabricated to observe the influence of Kerr signal asymmetry. This modifiable asymmetric Kerr signal advances the time-resolved measurements of vortex chirality dynamics.