Tuning Ginzburg-Landau theory to quantitatively study thin ferromagnetic materials

TL;DR

This paper introduces a tuned Ginzburg-Landau model that accurately simulates domain wall dynamics in thin ferromagnetic materials, aligning well with experimental data across different motion regimes.

Contribution

The work develops a material-specific Ginzburg-Landau model incorporating experimental parameters and thermal fluctuations for quantitative domain wall dynamics simulation.

Findings

Model reproduces experimental velocity-field data

Accurately captures creep, depinning, and flow regimes

Provides nano-scale insights into domain wall width

Abstract

Along with experiments, numerical simulations are key to gaining insight into the underlying mechanisms governing domain wall motion in thin ferromagnetic systems. However, a direct comparison between numerical simulation of model systems and experimental results still represents a great challenge. Here, we present a tuned Ginzburg-Landau model to quantitatively study the dynamics of domain walls in quasi two-dimensional ferromagnetic systems with perpendicular magnetic anisotropy. This model incorporates material and experimental parameters and the micromagnetic prescription for thermal fluctuations, allowing us to perform material-specific simulations and at the same time recover universal features. We show that our model quantitatively reproduces previous experimental velocity-field data in the archetypal perpendicular magnetic anisotropy Pt/Co/Pt ultra-thin films in the three dynamical regimes of domain wall motion (creep, depinning and flow). In addition, we present a statistical analysis of the domain wall width parameter, showing that our model can provide detailed nano-scale information while retaining the complex behavior of a statistical disordered model.