Instability of Walker Propagating Domain Wall in Magnetic Nanowires

TL;DR

This paper analytically investigates the stability of the Walker propagating domain wall in magnetic nanowires, revealing its instability due to spin wave emission and the influence of magnetic anisotropy on its stability and dynamics.

Contribution

It provides a detailed analytical study of the Walker domain wall stability, highlighting conditions leading to instability and the effects of magnetic anisotropy.

Findings

Walker DW mode is unstable against spin wave emission.

Different wave emissions occur under low and high magnetic fields.

High transverse anisotropy can destabilize the Walker solution below the breakdown field.

Abstract

Stability of the well-known Walker propagating domain wall (DW) solution of the Landau-Lifshitz-Gilbert equation is analytically investigated. Surprisingly, the Walker's rigid body propagating DW mode is not stable against the spin wave/wavepacket emission. In the low field region only stern spin waves are emitted while both stern and bow waves are generated under high fields. In a high enough field, but below the Walker breakdown field, the Walker solution could be convective/absolute unstable if the transverse magnetic anisotropy is larger than a critical value, corresponding to a significant modification of the DW profile and DW propagating speed.