Domain wall propagation through spin wave emission

TL;DR

This paper theoretically investigates how domain walls move in insulating ferromagnets via spin wave emission, revealing conditions for dissipationless propagation and stability issues related to damping and anisotropy.

Contribution

It introduces a theoretical model describing domain wall propagation through spin wave emission and analyzes stability and velocity regimes in insulating ferromagnets.

Findings

Domain walls can propagate dissipationlessly via spin wave emission at low fields.

Damping causes mode appearance before Walker breakdown in certain anisotropies.

Rigid-body propagation becomes unstable between maximal DW speed and Walker breakdown fields.

Abstract

We theoretically study field-induced domain wall (DW) motion in an electrically insulating ferromagnet with hard- and easy-axis anisotropies. DWs can propagate along a dissipationless wire through spin wave emission locked into the known soliton velocity at low fields. In the presence of damping, the mode appears before the Walker breakdown field for strong out-of-plane magnetic anisotropy, and the usual Walker rigid-body propagation mode becomes unstable when the field is between the maximal-DW-speed field and Walker breakdown field.