The current-driven motion of a domain wall (DW) in a ferromagnet with many Bloch lines (BLs) via the spin transfer torque is studied theoretically. It is found that the motion of BLs changes the current-velocity (j-v) characteristic dramatically. Especially, the critical current density to overcome the pinning force is reduced by the factor of the Gilbert damping coefficient α even compared with that of a skyrmion. This is in sharp contrast to the case of magnetic field driven motion, where the existence of BLs reduces the mobility of the DW.
@article{arxiv.1506.00723,
title = {Current-Driven Motion of Magnetic Domain Wall with Many Bloch Lines},
author = {Junichi Iwasaki and Naoto Nagaosa},
journal= {arXiv preprint arXiv:1506.00723},
year = {2015}
}