Density functional theory study of skyrmion pinning by atomic defects in MnSi

TL;DR

This study uses density functional theory to investigate how atomic defects in MnSi influence skyrmion pinning, revealing how substitutional elements can tune pinning energies with implications for spintronic applications.

Contribution

It provides a first-principles analysis of atomic defect effects on skyrmion pinning in MnSi, introducing a way to tune pinning energies via element substitution.

Findings

Atomic defects can significantly alter skyrmion pinning energies.

Substituting Mn or Si with different elements tunes the pinning strength.

A phenomenological model qualitatively explains defect-induced pinning effects.

Abstract

A magnetic skyrmion observed experimentally in chiral magnets is a topologically protected spin texture. For their unique properties, such as high mobility under current drive, skyrmions have huge potential for applications in next-generation spintronic devices. Defects naturally occurring in magnets have profound effects on the static and dynamical properties of skyrmions. In this work, we study the effect of an atomic defect on a skyrmion using the first-principles calculations within the density functional theory, taking MnSi as an example. By substituting one site of Mn or Si with different elements, we can tune the pinning energy. The effects of pinning by an atomic defect can be understood qualitatively within a phenomenological model.