Dzyaloshinskii-Moriya interaction and skyrmions in antiferromagnetic-based heterostructures

Abstract

The Dzyaloshinskii-Moriya interaction (DMI), an antisymmetric exchange format, plays a key role in the formation of chiral magnetic states. Here, a systematic study on the magnetic properties, including DMI, Heisenberg exchange coupling, and magnetocrystalline anisotropy of IrMn (PtMn) and MgO/IrMn (MgO/PtMn) stacks were carried out by first-principles calculation. Furthermore, the effect of DMI on topological magnetism in the above structures was investigated by micromagnetic simulations based on magnetic parameters from first-principles calculation. A large DMI and microscopic mechanisms of DMI at MgO/IrMn interface were unveiled. This interfacial DMI originates from the dominant contribution from the Ir layer and the orbital hybridization with Ir 3d orbit. The micromagnetic simulation indicates that the labyrinth domains with chiral domain walls and antiferromagnetic skyrmions appear for MgO/IrMn heterostructure, and isolated antiferromagnetic skyrmions are induced for MgO/PtMn heterostructure without any external magnetic fields. Our results may open up a new route to generate the magnetic antiferromagnetic skyrmions at oxide/antiferromagnetic interfaces, which can be an ideal information carrier.