Influence of the dynamic dipolar interaction on the current-induced core switch in vortex pairs

The effective manipulation of the orientation of a vortex core by spin-polarized currents introduces the technologically relevant possibility of addressing individual nanomagnets within large arrays. The vortex configuration, which minimizes the interactions between elements, in principle, allows for high integration densities. Using micromagnetic simulations, we find however that the polarity and vorticity of neighboring vortices can strongly modify the parameters necessary to trigger the core switch, increasing, for example, the switching currents as compared to an insolated disk. Such variations are attributed to the formation of charges during the vortex dynamics and can be interpreted using an analytical model based on the generalized Thiele equation. This model takes into account the dynamic dipolar interaction between neighboring vortices.