Effect of shape anisotropy on threshold current density for current-induced domain wall motion

Using micromagnetic simulations, the authors investigate the effects of the shape anisotropy of nanowires on the threshold current density ( J C ) in the adiabatic limit. It is observed that the type of domain wall significantly affects the dependence of J C on the shape anisotropy. For a transverse wall, J C is proportional to the shape anisotropy, but slightly deviates from the theoretical prediction [ G. Tatara and H. Kohno , Phys. Rev. Lett . 92 , 086601 ( 2004 ) ] possibly due to antivortex formation. For a vortex wall, J C is almost independent of the shape anisotropy, as experimentally observed [ A. Yamaguchi , Jpn. J. Appl. Phys. Part 1 45 , 3850 ( 2006 ) ]. Interestingly, J C and the velocity of the vortex wall at finite temperatures are in good agreement with the experimental values even when the nonadiabatic spin torque is not considered.