Unveiling the influence of fixed layer polarization on skyrmion nucleation and dynamics in circular geometry

Chiral magnetic skyrmion spin textures promise to be the next generation of energy-efficient computing. An effective way of skyrmion creation is essential to use as an information carrier. We report the creation of a skyrmion in a circular spin valve nanostructure using spin-polarized currents. This research investigates skyrmion nucleation under perpendicular and vortex fixed layer polarizations. The impact of Dzyaloshinskii-Moriya interaction (DMI), magnetic anisotropy, and saturation magnetization on the nucleation process has been studied for the perpendicular case. Depending on fixed layer polarization, we observed a trade-off between current density and pulse width for skyrmion nucleation. Vortex polarization enables faster nucleation at higher currents, while perpendicular polarization facilitates lower current thresholds at the expense of longer pulses. Further skyrmion dynamics have been explored under the sinusoidal magnetic fields.