Field-induced domain wall propagation velocity in magnetic nanowires

TL;DR

This paper develops a comprehensive theory for field-induced domain wall propagation in magnetic nanowires, providing a new velocity-field formula that aligns well with experimental and simulation data, and introduces a meaningful velocity definition.

Contribution

It introduces a novel theoretical framework for domain wall velocity, applicable to arbitrary structures, and derives a new velocity-field formula beyond the Walker breakdown.

Findings

The theory explains finite DW velocity in defect-free nanowires.

A new velocity-field formula matches experimental and simulation results.

A proper definition of DW velocity applicable to non-rigid structures is provided.

Abstract

A thory of field-induced domain wall (DW) propagation is developed. The theory not only explains why a DW in a defect-free nanowire must propagate at a finite velocity, but also provides a proper definition of DW propagation velocity. This definition, valid for an arbitrary DW structure, allows one to compute the instantaneous DW velocity in a meaningful way even when the DW is not moving as a rigid body. A new velocity-field formula beyond the Walker breakdown field, which is in excellent agreement with both experiments and numerical simulations, is derived.