Current research on skyrmions uses stacks combining layers of magnetic metals (e.g. cobalt or iron) and heavy metals (e.g. platinum or iridium) in order to promote the required magnetic interactions.

In this collaborative work, physicists predict that skyrmions may also exist in monolayers of Janus-type transition metal dichalcogenides such as MnSTe or MnSeTe, a new class of two-dimensional magnetic materials like graphene (a monolayer of carbon atoms). Indeed, these monolayers posess structural inversion asymmetry necessary for magnetic interactions responsible for the formation of skyrmions (Dzyaloshinskii-Moriya interaction). In addition, they contain heavy atoms (tellurium) that make this interaction stronger.

The researchers relied on ab initio calculations to evaluate Dzyaloshinskii-Moriya interaction that is just as pronounced in MnSTe or MnSeTe as in conventional multilayers and on Monte-Carlo simulations showing that skyrmions can be stabilized at low temperatures and in the presence of a magnetic field. The theoretical predictions of the temperature and magnetic field ranges for skyrmions onbservations in MnSTe or MnSeTe will help guiding a new experimental exploration of these fascinating topological magnetic objects, skyrmions.

This work is the result of a collaboration between the Spintec (Irig), the Unité Mixte de Physique at the CNRS-Thales (Palaiseau), and researchers from the Ningbo Institute of Materials Technology and Engineering (China).