Universality of defect-skyrmion interaction profiles

TL;DR

This study reveals a universal shape of the energy profile for skyrmion-defect interactions, based on first-principles calculations, which can predict how different impurities influence skyrmion behavior in spintronic devices.

Contribution

It establishes a universal interaction profile shape for skyrmions with defects, linking electronic structure to interaction behavior, aiding device design.

Findings

Interaction profiles depend on defect electron filling

Foreign transition metal adatoms can repel or pin skyrmions

Universal shape relates to electronic bonding states

Abstract

Magnetic skyrmions are prime candidates for future spintronic devices. However, incorporating them as an entity for information technology hinges on their interaction with defects ubiquitous to any device. Here we map from first-principles, the energy-profile of single skyrmions interacting with single-atom impurities, establishing a generic shape as function of the defect's electron filling. Depending on their chemical nature, foreign 3d and 4d transition metal adatoms or surface-implanted defects can either repel or pin skyrmions in PdFe/Ir(111) thin films, which we relate to the degree of filling of bonding and anti-bonding electronic states inherent to the proximity of the non-collinear magnetic structure. Similarities with key concepts of bond theories in catalysis and surface sciences imbue the universality of the shape of the interaction profile and the potential of predicting its interaction. The resulting fundamental understanding may give guidance for the design of devices with surface-implanted defects to generate and control skyrmions.