# Structural transitions of skyrmion lattices in synthetic antiferromagnets

## TL;DR

This paper demonstrates how the skyrmion lattice structure in synthetic antiferromagnetic films can be switched between square and hexagonal configurations by tuning interlayer coupling, affecting potential spintronic applications.

## Contribution

It reveals a tunable transition between square and hexagonal skyrmion lattices in synthetic antiferromagnets via Monte Carlo simulations, providing a new control mechanism.

## Key findings

- Skyrmion lattice structure can be tuned from square to hexagonal.
- Interlayer coupling controls the lattice configuration.
- Skyrmions in different layers repel and form dual lattices.

## Abstract

Thin magnetic films with Dzyaloshinskii-Moriya interactions are known to host skyrmion crystals, which typically have a hexagonal lattice structure. We investigate skyrmion-lattice configurations in synthetic antiferromagnets, i.e., a bilayer of thin magnetic films that is coupled antiferromagnetically. By means of Monte-Carlo simulations, we find that by tuning the interlayer coupling the skyrmion lattice structure can be tuned from square to hexagonal. We give a simple interpretation for the existence of this transition based on the fact that for synthetic antiferromagnetic coupling the skyrmions in different layers repel each other and form each others' dual lattice. Our findings may be useful to experimentally switch between two lattice configurations to, for example, modify spin-wave propagation.