Significant Dzyaloshinskii–Moriya interaction at graphene–ferromagnet interfaces due to the Rashba effect

Abstract

The possibility of utilizing the rich spin-dependent properties of graphene has attracted much attention in the pursuit of spintronics advances. The promise of high-speed and low-energy-consumption devices motivates the 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. Graphene is a weak spin–orbit coupling material and is generally not expected to induce a sufficient Dzyaloshinskii–Moriya interaction to affect magnetic chirality. We demonstrate that indeed graphene does induce a type of Dzyaloshinskii–Moriya interaction due to the Rashba effect. First-principles calculations and experiments using spin-polarized electron microscopy show that this graphene-induced Dzyaloshinskii–Moriya interaction can have a similar magnitude to that at interfaces with heavy metals. This work paves a path towards two-dimensional-material-based spin–orbitronics.Authors investigate graphene/cobalt and graphene/nickel interfaces, and observe a non-zero Dzyaloshinskii–Moriya interaction that they attribute to the Rashba effect; calculations suggest the effect can be enhanced in van der Waals heterostructures.