Significant Dzyaloshinskii-Moriya Interaction at Graphene-Ferromagnet Interfaces due to Rashba-effect

TL;DR

This paper reveals that graphene/ferromagnet interfaces can induce significant Dzyaloshinskii-Moriya interactions through a Rashba effect, enabling chiral spin textures and advancing 2D material spintronics.

Contribution

It demonstrates, both theoretically and experimentally, that graphene can induce substantial Dzyaloshinskii-Moriya interactions via Rashba effect, contrary to previous expectations.

Findings

Graphene induces a Dzyaloshinskii-Moriya interaction comparable to heavy metal interfaces.

Chiral spin textures are stabilized at graphene/ferromagnetic interfaces.

First-principles calculations confirm the Rashba-induced Dzyaloshinskii-Moriya interaction.

Abstract

The possibility of utilizing the rich spin-dependent properties of graphene has attracted great attention in pursuit of spintronics advances. The promise of high-speed and low-energy consumption devices motivates a search for layered structures that stabilize chiral spin textures such as topologically protected skyrmions. Here we demonstrate that chiral spin textures are induced at graphene/ferromagnetic metal interfaces. This is unexpected because graphene is a weak spin-orbit coupling material and is generally not expected to induce sufficient Dzyaloshinskii-Moriya interaction to affect magnetic chirality. We demonstrate that graphene induces a new type of Dzyaloshinskii-Moriya interaction due to a Rashba effect. First-principles calculations and experiments using spin-polarized electron microscopy show that this graphene-induced Dzyaloshinskii-Moriya interaction can have similar magnitude as at interfaces with heavy metals. This work paves a new path towards two-dimensional material based spin orbitronics.