# Barkhausen noise from precessional domain wall motion

## TL;DR

This paper investigates Barkhausen noise caused by precessional domain wall motion in disordered ferromagnetic thin films, revealing the role of Bloch lines and internal domain wall dynamics through micromagnetic simulations.

## Contribution

It provides a detailed micromagnetic simulation study of Barkhausen noise, highlighting the internal structure and topological defects within domain walls during precessional motion.

## Key findings

- Bloch lines nucleate, propagate, and annihilate during Barkhausen jumps.
- In-plane Bloch line dynamics dominate spin rotation activity.
- Precessional domain wall motion produces crackling noise in disordered ferromagnets.

## Abstract

The jerky dynamics of domain walls driven by applied magnetic fields in disordered ferromagnets -- the Barkhausen effect -- is a paradigmatic example of crackling noise. We study Barkhausen noise in disordered Pt/Co/Pt thin films due to precessional motion of domain walls using full micromagnetic simulations, allowing for a detailed description of the domain wall internal structure. In this regime the domain walls contain topological defects known as Bloch lines which repeatedly nucleate, propagate and annihilate within the domain wall during the Barkhausen jumps. In addition to bursts of domain wall propagation, the in-plane Bloch line dynamics within the domain wall exhibits crackling noise, and constitutes the majority of the overall spin rotation activity.