Enhancing Domain Wall Speed in Nanowires with Transverse Magnetic Fields

TL;DR

This study uses micromagnetic simulations to demonstrate that applying a transverse magnetic field can significantly increase the maximum speed of domain walls in nanowires, with effects depending on the field's alignment.

Contribution

The paper introduces a new method of increasing domain wall speed using transverse magnetic fields, supported by simulation data and a simple theoretical model.

Findings

Maximum domain wall speed increased by up to 20% with transverse field.

Domain wall length varies linearly with transverse field strength.

Alignment of the transverse field with magnetic moments enhances velocity increase.

Abstract

Dynamic micromagnetic simulation studies have been completed to observe the motion of a domain wall in a magnetic nanowire in an effort to increase the field-driven domain wall speed. Previous studies have shown that the wire dimensions place a cap on the maximum speed attainable by a domain wall when driven by a magnetic field placed along the direction of the nanowire. Here we present data showing a significant increase in the maximum speed of a domain wall due to the addition of a magnetic field placed perpendicular to the longitudinal driving field. The results are expressed in terms of the relative alignment of the transverse field direction with respect to the direction of the magnetic moments within the domain wall. In particular, when the transverse field is parallel to the magnetic moments within the domain wall, the velocity of the wall varies linearly with the strength of the transverse field increasing by up to 20%. Further examination of the domain wall structure shows that the length of the domain wall also depends linearly on the strength of the transverse field. We present a simple model to correlate the effects.