Electrical manipulation of skyrmions in a chiral magnet

TL;DR

This paper demonstrates the electrical creation, deletion, and manipulation of magnetic skyrmions in a chiral magnet device at room temperature using nanosecond current pulses, advancing skyrmion-based memory technology.

Contribution

It introduces a method to electrically control skyrmions in a micro-device, enabling all three basic operations with low current density at room temperature.

Findings

Skyrmions can be created or deleted using notched structures and current pulses.

Magnetic skyrmions can be deterministically shifted step-by-step.

A universal current-velocity relationship for skyrmion motion is established.

Abstract

Writing, erasing and computing are three fundamental operations required by any working electronic devices. Magnetic skyrmions could be basic bits in promising in emerging topological spintronic devices. In particular, skyrmions in chiral magnets have outstanding properties like compact texture, uniform size and high mobility. However, creating, deleting and driving isolated skyrmions, as prototypes of aforementioned basic operations, have been grand challenge in chiral magnets ever since the discovery of skyrmions, and achieving all these three operations in a single device is highly desirable. Here, by engineering chiral magnet Co$_8$Zn$_{10}$Mn$_2$ into the customized micro-devices for in-situ Lorentz transmission electron microscopy observations, we implement these three operations of skyrmions using nanosecond current pulses with a low a current density about $10^{10}$ A/m$^2$ at room temperature. A notched structure can create or delete magnetic skyrmions depending on the direction and magnitude of current pulses. We further show that the magnetic skyrmions can be deterministically shifted step-by-step by current pulses, allowing the establishment of the universal current-velocity relationship. These experimental results have immediate significance towards the skyrmion-based memory or logic devices.