Independent Control of the Chirality and Polarity for the Magnetic Vortex in Symmetric Nanodot Pairs

We studied the vortex states during the magnetization process for nanomagnetic dot pairs in different geometries, including a series of dual regular polygons with 4-16 sides and irregular shape dot pairs. All geometries demonstrated independent control of the vortex chirality and polarity and could be accomplished by adjusting the in-plane magnetic field direction. To achieve chirality and polarity control, both shape anisotropy and coupling interaction play a vital role. For the regular polygons, the effect of shape anisotropy wanes as the number of side increases, and the coupled interaction is enhanced relatively. According to the results, and combined with those for dual-circle and dual-rectangular magnetic disks, we state the principle for the geometry of the disk to achieve independent control of the chirality and polarity.