Current-induced vortex displacement and annihilation in a single permalloy disk

The induced motion of a magnetic vortex in a micron-sized ferromagnetic disk due to the dc current injection is studied by measuring planar Hall effect. We demonstrated that the vortex motion induced by the dc current injection has no threshold current and is proportional to the injecting current. The induced displacement deduced from the change in planar Hall resistance is quantitatively consistent with theoretical predictions. The dc current injection is also found to induce the spin torque that sweeps the vortex out of the disk at the critical current while bias magnetic fields are applied. Peak structures similar to those originated from spin wave excitations are observed in the differential planar Hall resistance curve.