Dynamics of domain walls in magnetic nanostrips

TL;DR

This paper develops a generalized theoretical framework for understanding the dynamics of domain walls in magnetic nanostrips, accurately describing their behavior under various magnetic field conditions.

Contribution

It introduces a collective coordinate approach extending Thiele's results, providing a quantitative two-mode approximation for domain wall motion in nanowires.

Findings

Two-mode approximation accurately models steady and oscillatory domain wall motion.

The approach applies to vortex walls in flat nanowires.

Quantitative agreement with experimental observations.

Abstract

We express dynamics of domain walls in ferromagnetic nanowires in terms of collective coordinates generalizing Thiele's steady-state results. For weak external perturbations the dynamics is dominated by a few soft modes. The general approach is illustrated on the example of a vortex wall relevant to recent experiments with flat nanowires. A two-mode approximation gives a quantitatively accurate description of both the steady viscous motion of the wall in weak magnetic fields and its oscillatory behavior in moderately high fields above the Walker breakdown.