Magnetic chirality controlled by the interlayer exchange interaction

TL;DR

This study demonstrates that interlayer exchange interaction can be used to control magnetic chirality in layered systems, providing a new tool for designing spintronic devices with specific magnetic textures.

Contribution

It introduces the use of interlayer exchange interaction as a novel method to manipulate magnetic chirality, expanding the control mechanisms beyond iDMI and dipolar interactions.

Findings

Interlayer exchange coupling induces a transition from N�eel to Bloch-N�el domain walls.

Magnetic chirality can be uniformly controlled across layers by tuning interlayer exchange.

Simulation results support experimental observations and suggest applications in skyrmion-based devices.

Abstract

Chiral magnetism, wherein there is a preferred sense of rotation of the magnetization, has become a key aspect for future spintronic applications. It determines the chiral nature of magnetic textures, such as skyrmions, domain walls or spin spirals, and a specific magnetic chirality is often required for spintronic applications. Current research focuses on identifying and controlling the interactions that define the magnetic chirality. The influence of the interfacial Dzyaloshinskii-Moriya interaction (iDMI) and, recently, the dipolar interactions have previously been reported. Here, we experimentally demonstrate that an indirect interlayer exchange interaction can be used as an additional tool to effectively manipulate the magnetic chirality. We image the chirality of magnetic domain walls in a coupled bilayer system using scanning electron microscopy with polarization analysis (SEMPA). Upon increasing the interlayer exchange coupling, we induce a transition of the magnetic chirality from clockwise rotating N\'eel walls to degenerate Bloch-N\'eel domain walls and we confirm our findings with micromagnetic simulations. In multi-layered systems relevant for skyrmion research a uniform magnetic chirality across the magnetic layers is often desired. Additional simulations show that this can be achieved for reduced iDMI values when exploiting the interlayer exchange interaction. This work opens up new ways to control and tailor the magnetic chirality by the interlayer exchange interaction.