Controlled propagation of locally excited vortex dynamics in linear nanomagnet arrays

The ability to propagate local electromagnetic excitation in a medium with spatially modulated physical properties is important for fundamental science and also for applications in photonic, phononic and magnonic crystals. Here, we present a controlled propagation of locally excited magnetic vortex dynamics through a linear array of nanomagnetic discs by controlling the polarization, chirality and shape of the discs. The control is based upon the magnetostatic interaction between the nanodiscs, mediated by the magnetic side charges generated by the gyrating vortices. The magnitude and sign of the side charges and their separation depend strongly on the magnetic ground states of the vortices, including the core polarization and the chirality. We find that the transmission of peak amplitude and velocity of propagation of the excitation along the array is optimized for identical core polarization and chirality of the nanodiscs with geometric asymmetry. More than seven times increase in the transmitted amplitude is observed in the optimized structure as opposed to the non-optimized structure, which is also found to be robust to defects.