Investigation of stabilization and survival of skyrmion vortices in the presence of magnetic field disorder in two-dimensional lattices: a case study for Janus dichalcogenides

Abstract

As a result of the lack of inversion symmetry, very large Dzyaloshinskii-Moriya interaction (DMI) has been reported for a series of Janus monolayers of manganese dichalcogenides within the framework of first-principles calculations (Liang et al. \textit{Phys. Rev. B} \textbf{101}, 184401 (2020)). However, from the viewpoint of potential applications, the current ongoing research mainly focuses on the magnetism in pristine 2D materials exhibiting non-zero DMI, and the effects of disorder in such systems remain an open problem since the influence of randomness may create some drastic effects on the magnetism of low dimensional systems.
Here,we present Monte Carlo simulation results regarding the magnetic properties of a two-dimensional manganese based Janus dichalcogenide material $\mathrm{MnSTe}$ in the presence of quenched random magnetic fields where the local field variables have been sampled from a Gaussian distribution. For the selected benchmark material,
it has been found that the magnetic skyrmion vortexes emerging at $(10K,3T)$ may survive in the presence of weak and moderate quenched randomness which is important from viewpoint of technological applications.
Both in the pristine and random field cases, the stabilization of magnetic skyrmions are achieved by 
the major contribution of the ferromagnetic exchange energy to the total energy of the system, and the materials exhibiting large DMI/exchange ratios may exhibit resilient magnetic skyrmion vortexes in the presence of weak and moderate amount of randomness.