Engineering Skyrmions In Transition-Metal Multilayers For Spintronics

Magnetic skyrmions are localized, topologically protected spin structures that have been<br> proposed for storing or processing information due to their intriguing dynamical and transport<br> properties. Important in terms of applications is the recent discovery of interface stabilized<br> skyrmions as evidenced in ultra-thin transition-metal films. However, so far only skyrmions at<br> interfaces with a single atomic layer of a magnetic material were reported, which greatly<br> limits their potential for application in devices. Here we predict the emergence of skyrmions<br> in [4d/Fe2/5d]n multilayers, that is, structures composed of Fe biatomic layers sandwiched<br> between 4d and 5d transition-metal layers. In these composite structures, the exchange<br> and the Dzyaloshinskii–Moriya interactions that control skyrmion formation can be tuned<br> separately by the two interfaces. This allows engineering skyrmions as shown based on<br> density functional theory and spin dynamics simulations.