Effects of current on vortex and transverse domain walls

TL;DR

This paper compares how vortex and transverse domain walls in ferromagnets respond to electrical currents, highlighting differences in pinning, mobility, and transformation behavior under various conditions.

Contribution

It introduces a phase diagram illustrating current-driven mobility and transformation of domain walls, emphasizing the distinct responses of vortex and transverse walls.

Findings

Vortex walls require lower current to overcome pinning than transverse walls.

Vortex walls tend to transform into transverse walls during motion.

Steady state mobility is independent of wall structure in defect-free samples.

Abstract

By using the spin torque model in ferromagnets, we compare the response of vortex and transverse walls to the electrical current. For a defect-free sample and a small applied current, the steady state wall mobility is independent of the wall structure. In the presence of defects, the minimum current required to overcome the wall pinning potential is much smaller for the vortex wall than for the transverse wall. During the wall motion, the vortex wall tends to transform to the transverse wall. We construct a phase diagram for the wall mobility and the wall transformation driven by the current.