Intrinsic skyrmions in monolayer Janus magnets

TL;DR

This paper explores the existence and properties of intrinsic skyrmions in monolayer Janus magnets, revealing their stabilization mechanisms, size tunability, and potential for atomic-scale magnetic applications.

Contribution

It demonstrates the presence of intrinsic skyrmions in specific monolayer Janus magnets using first-principles and micromagnetic simulations, highlighting their unique stabilization without external fields.

Findings

Intrinsic skyrmions stabilized in MnSTe and MnSeTe monolayers at zero magnetic field.

Skyrmion size and shape can be tuned by external magnetic fields.

VSeTe forms magnetic domains instead of skyrmions due to in-plane easy axis.

Abstract

Skyrmions are localized solitonic spin textures with protected topology, which are promising as information carriers in ultra-dense and energy-efficient logic and memory devices. Recently, magnetic skyrmions have been observed in magnetic thin films, and are stabilized by the extrinsic interfacial Dzyaloshinskii-Moriya interaction (DMI) and/or external magnetic fields. The specific effects in magnetic monolayer materials have not been thoroughly studied. Here, we investigate the intrinsic magnetic skyrmions in a family of monolayer Janus van der Waals magnets, MnSTe, MnSeTe, VSeTe, and MnSSe, by the first-principles calculations combined with the micromagnetic simulations. The monolayer Janus MnSTe, MnSeTe, and VSeTe with out-of-plane geometric asymmetry and strong spin-orbit coupling (SOC) have a large intrinsic DMI, which could stabilize a sub-50 nm intrinsic skyrmions in monolayer MnSTe and MnSeTe at zero magnetic field. While monolayer VSeTe with in-plane easy axis forms magnetic domain rather than skyrmions. Moreover, the size and shape of skyrmions can be tuned by an external magnetic field. Therefore, our work motivates a new vista for seeking intrinsic skyrmions in atomic-scale magnets.