A mechanism to pin skyrmions in chiral magnets

TL;DR

This paper introduces a method to control skyrmion positions in chiral magnets by creating local exchange strength maxima, enabling precise manipulation for potential spintronic applications.

Contribution

It presents a novel mechanism for pinning skyrmions via engineered local exchange maxima in chiral magnetic thin films, supported by simulations of pinning and depinning dynamics.

Findings

Critical depinning current depends linearly on pinning strength.

Estimated critical current for depinning is between 10^7 and 10^8 A/m^2.

The proposed method allows for controlled skyrmion positioning.

Abstract

We propose a mechanism to pin skyrmions in chiral magnets by introducing local maximum of magnetic exchange strength, which can be realized in chiral magnetic thin films by engineering the local density of itinerate electrons. Thus we find a way to artificially control the position of a single skyrmion in chiral magnetic thin films. The stationary properties and the dynamical pinning and depinning processes of an isolated skyrmion around a pinning center are studied. We do a series of simulations to show that the critical current to depin a skyrmion has linearly dependence on the pinning strength. We also estimate the critical current to have order of magnitude 10^{7}\sim10^{8}A/m^{2} .