Creating arbitrary sequences of mobile magnetic skyrmions and antiskyrmions

TL;DR

This paper introduces a method to create and control arbitrary sequences of stable magnetic skyrmions and antiskyrmions in a device, enabling advanced memory applications by manipulating their edge rotations.

Contribution

It presents a novel technique for generating arbitrary sequences of coexisting skyrmions and antiskyrmions through edge magnetic moment rotations, preventing their annihilation.

Findings

Stable coexistence of skyrmions and antiskyrmions achieved.

Method allows creation of arbitrary sequences.

Potential for advanced racetrack memory devices.

Abstract

Magnetic skyrmions and their anti-particles, the antiskyrmions, are stable magnetic solitons existing down to the nanometer scale. Their stability and size as well as the possibility to propel them by, e.g., electric currents make them promising candidates for the use in memory devices, such as racetrack memories. Skyrmions and antiskyrmions share those same advantages individually, but may annihilate each other when they coexist in the same device. Yet, combining them to represent logical bits of 0 (skyrmion) and 1 (antiskyrmion) in one device opens new possibilities to create new types of densely packed racetrack memory devices. For this, a controlled creation and annihilation procedure, i.e., a writing or deletion operation, is necessary. Here, we propose a method to create arbitrary sequences of coexisting skyrmions and antiskyrmions by rotations of the magnetic moments at the edge of a rectangular slab. The skyrmions and antiskyrmions remain stable and do not annihilate each other.