Driving skyrmions with low threshold current density in Pt/CoFeB thin film

Magnetic skyrmions are topologically stable spin swirling particle like entities which are appealing for next generation spintronic devices. The expected low critical current density for the motion of skyrmions makes them potential candidates for future energy efficient electronic devices. Several heavy metal/ferromagnetic (HM/FM) systems have been explored in the past decade to achieve faster skyrmion velocity at low current densities. In this context, we have studied Pt/CoFeB/MgO heterostructures in which skyrmions have been stabilized at room temperature (RT). It has been observed that the shape of the skyrmions are perturbed even by the small stray field arising from low moment magnetic tips while performing the magnetic force microscopy (MFM), indicating presence of low pinning landscape in the samples. This hypothesis is indeed confirmed by the low threshold current density to drive the skyrmions in our sample, at velocities of few similar to 10 m s(-1).

Automated summary

Magnetic skyrmions are topologically stable spin swirling particles that hold promise for future spintronic devices. The low critical current density required for their motion makes them attractive for energy efficient electronic devices. In this study, the Pt/CoFeB/MgO heterostructures were investigated and skyrmions were successfully stabilized at room temperature. The presence of a low pinning landscape in the samples was confirmed by the distortion of skyrmion shape even under the influence of weak magnetic fields from low moment magnetic tips during magnetic force microscopy (MFM) scans. The threshold current density required to drive the skyrmions in our sample was found to be low, with velocities of few 10 m/s.