Current-induced vortex domain wall depinning in ferromagnetic nanowires with artificial linear defect

Vortex domain wall depinning has been obtained in ferromagnetic nanowires with linear defect under the influence of spin transfer torque effect. It is demonstrated that vortex domain wall will be pinned at defect line in ferromagnetic nanowires under small applied current field. Moreover, the depinning of domain wall is strongly dependent on saturation magnetization and exchange coupling constant in linear defect region of magnetic nanowires. We have also discussed linear defect geometry modifying the depinning of domain wall, which is caused by the competition between demagnetization effect and exchange coupling effect.