Current-Driven Domain Wall Motion: Velocity, Current and Phase Transition

TL;DR

This paper presents a phenomenological phase transition model for current-driven domain wall motion, explaining velocity behavior, critical current, and temperature effects, aligning with experimental observations.

Contribution

It introduces a Landau-like phase transition framework to describe domain wall velocity and critical current dependence on current density and temperature.

Findings

Velocity depends on current density as a square root near the critical point

At high currents, velocity becomes linearly proportional to current

Temperature influences the critical current and domain wall dynamics

Abstract

The relation between domain wall motion and intensity of driven current is examined in a phenomenological theory where the kinetic energy is expanded as a series of polynomial function of current density just as the Landau phase transition theory. The dependency of velocity on current density is root square which degenerates into linear if the current is much higher than the critical value. The theory result is consistent with several previous experiments and also can explain the change of critical current in the presence of temperature. The role of temperature plays in the dynamics of domain wall motion is also discussed. The phase transition theory in terms of current density is employed to explain the critical behavior of domain wall motion.