Understanding of complex periodic transformations of moving domain walls in magnetic nanostripes

TL;DR

This paper investigates the complex periodic behaviors of moving domain walls in magnetic nanostripes under strong magnetic fields, revealing new periodicities and transformation mechanisms involving magnetic topological solitons.

Contribution

It uncovers previously unknown periodic transformations of domain walls and links these behaviors to magnetic topological solitons, advancing understanding of domain-wall dynamics.

Findings

Identified three unique periodicities in domain-wall transformations.

Demonstrated the dependence of periodicities on field strength and nanostripe width.

Linked domain-wall behaviors to vortex and antivortex solitons.

Abstract

The magnetic field (or electric current) driven domain-wall motion in magnetic nanostripes is of considerable interest because it is essential to the performance of information storage and logic devices. One of the currently key problems is to unveil the complex behaviors of oscillatory domain-wall motions under applied magnetic fields stronger than the so-called Walker field, beyond which the velocity of domain walls markedly drops. Here, we provide not only considerably better understandings but also new details of the complex domain-wall motions. In a certain range just above the Walker field, the motions are not chaotic but rather periodic with different unique periodicities of dynamic transformations of a moving domain wall between the different types of its internal structure. Three unique periodicities found, which consist of different types of domain wall that are transformed from type one to another. The transformation periods vary with the field strength and the nanostripe width. This novel phenomenon can be described by the dynamic motion of a limited number of magnetic topological solitons such as vortex and antivortex in nanostripes.