The magnonic limit of domain wall propagation in ferromagnetic nanotubes

TL;DR

This study investigates vortex-like domain wall dynamics in ferromagnetic nanotubes, revealing that their velocity can reach spin wave speeds without Walker breakdown, accompanied by spin wave emission.

Contribution

It demonstrates that in ferromagnetic nanotubes, domain walls can attain high velocities limited only by spin wave dispersion, unlike in flat geometries.

Findings

Domain walls reach ~1000 m/s velocity

Velocity is not limited by Walker breakdown

Spin wave tails are emitted during propagation

Abstract

We report a study on the field-driven propagation of vortex-like domain walls in ferromagnetic nanotubes. This particular geometry gives rise to a special feature of the static wall configuration, which significantly influences its dynamics. Unlike domain walls in flat strips, the left-right symmetry of domain wall propagation is broken. Furthermore, the domain wall velocity is not limited by the Walker breakdown. Under sufficiently large magnetic fields, the domain wall velocity reaches the velocity of spin waves (about 1000 m/s) and is thereafter connected with a direct emission of spin waves. The moving domain wall maintains its main structure but has characteristic spin-wave tails attached. The spatial profile of this topological soliton is determined by the spin-wave dispersion.