Spin Wave Emission in Field-Driven Domain Wall Motion

TL;DR

This paper investigates how domain walls in nanowires emit spin waves during motion under magnetic fields, revealing different emission patterns and behaviors depending on anisotropy and field strength.

Contribution

It provides a numerical analysis of spin wave emission characteristics and their relation to domain wall dynamics under various anisotropy and magnetic field conditions.

Findings

Low anisotropy and high field cause bidirectional spin wave emission with slow DW movement.

High anisotropy and weak field lead to unidirectional stern wave emission and faster DW propagation.

DW behavior varies significantly with anisotropy and magnetic field strength.

Abstract

A domain wall (DW) in a nanowire can propagate under a longitudinal magnetic field by emitting spin waves (SWs). We numerically investigated the properties of SWs emitted by the DW motion, such as frequency and wavenumber, and their relation with the DW motion. For a wire with a low transverse anisotropy and in a field above a critical value, a DW emits SWs to both sides (bow and stern), while it oscillates and propagates at a low average speed. For a wire with a high transverse anisotropy and in a weak field, the DW emits mostly stern waves, while the DW distorts itself and DW center propagates forward like a drill at a relative high speed.