(a) Family of FORCs of the hybrid sample measured in the in-plane geometry. The zoomed-in view in (b) illustrates essentially two discrete vortex annihilation fields. Remanent-state (c) MFM and (d) SEMPA (superimposed onto a scanning electron microscopy image of the dots) images, after saturating the dots in an in-plane field parallel to the flat edge of the dots to the right, indicate circularity control. Scale bar, 2 μm. A key to the magnetization winding direction is shown in the insets.