A repulsive skyrmion chain as guiding track for a race track memory

TL;DR

This paper proposes a novel skyrmion racetrack design with dynamically controlled pinning sites using skyrmion repulsion, enabling thermally stable and reliably spaced skyrmion-based memory for race track applications.

Contribution

It introduces a dynamic pinning mechanism using skyrmion repulsion to improve stability and control in skyrmion racetrack memory devices, addressing limitations of static pinning sites.

Findings

Skyrmion chain maintains equal spacing due to repulsive interactions.

The energy barrier for data loss is calculated as 55 kBT, ensuring thermal stability.

The design enables reliable coding of information via skyrmion presence or absence.

Abstract

A skyrmion racetrack design is proposed that allows for thermally stable skyrmions to code information and dynamical pinning sites that move with the applied current. This concept solves the problem of intrinsic distributions of pinning times and pinning currents of skyrmions at static geometrical or magnetic pinning sites. The dynamical pinning sites are realized by a skyrmion carrying wire, where the skyrmion repulsion is used in order to keep the skyrmions at equal distances. The information is coded by an additional layer where the presence and absence of a skyrmion is used to code the information. The lowest energy barrier for a data loss is calculated to be DE = 55 kBT300 which is sufficient for long time thermal stability.