  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 10m/s.
