Dynamics of ferrimagnetic skyrmionium driven by spin-orbit torque

TL;DR

This paper investigates the dynamics of ferrimagnetic skyrmionium driven by spin-orbit torque, revealing its stability, motion characteristics, and potential for spintronic applications, especially near the angular momentum compensation point.

Contribution

It provides the first detailed analysis of ferrimagnetic skyrmionium dynamics under spin-orbit torque, highlighting its robustness and unique motion properties compared to ferromagnetic and antiferromagnetic skyrmioniums.

Findings

Ferrimagnetic skyrmionium is most stable at the angular momentum compensation point.

The skyrmion Hall effect is suppressed in ferrimagnetic skyrmioniums.

Ferrimagnetic skyrmioniums exhibit similar dynamics to antiferromagnetic skyrmioniums.

Abstract

Magnetic skyrmionium is a skyrmion-like spin texture with nanoscale size and high mobility. It is a topologically trivial but dynamically stable structure, which can be used as a non-volatile information carrier for next-generation spintronic storage and computing devices. Here, we study the dynamics of a skyrmionium driven by the spin torque in a ferrimagnetic nanotrack. It is found that the direction of motion is jointly determined by the internal configuration of a skyrmionium and the spin polarization vector. Besides, the deformation of a skyrmionium induced by the intrinsic skyrmion Hall effect depends on both the magnitude of the driving force and the net angular momentum. The ferrimagnetic skyrmionium is most robust at the angular momentum compensation point, whose dynamics is quite similar to the skyrmionium in antiferromagnet. The skyrmion Hall effect is perfectly prohibited, where it is possible to observe the position of the skyrmionium by measuring the magnetization. Furthermore, the current-induced dynamics of a ferrimagnetic skyrmionium is compared with that of a ferromagnetic and antiferromagnetic skyrmionium. We also make a comparison between the motion of a ferrimagnetic skyrmionium and a skyrmion. Our results will open a new field of ferrimagnetic skyrmioniums for future development of ferrimagnetic spintronics devices.