We study realizations of spirals and skyrmions in two-dimensional antiferromagnets with a triangular lattice on an inversion-symmetry-breaking substrate. As a possible material realization, we investigate the adsorption of transition-metal atoms (Cr, Mn, Fe, or Co) on a monolayer of ${\mathrm{MoS}}_2$, ${\mathrm{WS}}_2$, or ${\mathrm{WSe}}_2$ and obtain the exchange, anisotropy, and Dzyaloshinskii-Moriya interaction parameters using first-principles calculations. Using energy minimization and parallel-tempering Monte Carlo simulations, we determine the magnetic phase diagrams for a wide range of interaction parameters. We find that skyrmion lattices can appear even with weak Dzyaloshinskii-Moriya interactions, but their stability is hindered by magnetic anisotropy. However, a weak easy plane magnetic anisotropy can be beneficial for stabilizing the skyrmion phase. Our results suggest that Cr/${\mathrm{MoS}}_2$, Fe/${\mathrm{MoS}}_2$, and Fe/${\mathrm{WSe}}_2$ interfaces can host spin spirals formed from the ${120}^{\circ }$ antiferromagnetic states. Our results further suggest that for interfaces, such as Fe/${\mathrm{MoS}}_2$, the Dzyaloshinskii-Moriya interaction is strong enough to drive the system into a three-sublattice skyrmion lattice in the presence of experimentally feasible external magnetic field.

中文翻译：

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反铁磁三角晶格中的螺旋形和天空形

我们研究了在反对称打破衬底上具有三角形晶格的二维反铁磁体中螺旋形和天空形的实现。作为一种可能的材料实现方法，我们研究了过渡金属原子（Cr，Mn，Fe或Co）在单分子膜上的吸附${\mathrm{硫化钼}}_{\mathrm{2个}}$， ${\mathrm{WS}}_{\mathrm{2个}}$， 或者 ${\mathrm{硒化钨}}_{\mathrm{2个}}$并使用第一性原理计算获得交换，各向异性和Dzyaloshinskii-Moriya相互作用参数。使用能量最小化和并行回火蒙特卡洛模拟，我们确定了各种相互作用参数的磁相图。我们发现即使具有弱的Dzyaloshinskii-Moriya相互作用，也可以出现skyrmion晶格，但是它们的稳定性受到磁各向异性的影响。但是，较弱的易平面磁各向异性可能有利于稳定天敌离子相。我们的结果表明Cr /${\mathrm{硫化钼}}_{\mathrm{2个}}$，铁/${\mathrm{硫化钼}}_{\mathrm{2个}}$和Fe /${\mathrm{硒化钨}}_{\mathrm{2个}}$ 界面可以容纳由 ${120}^{\circ }$反铁磁态。我们的结果进一步表明，对于界面，例如Fe /${\mathrm{硫化钼}}_{\mathrm{2个}}$，Dzyaloshinskii-Moriya相互作用足够强大，可以在存在实验上可行的外部磁场的情况下将系统驱动为三子晶格的Skyrmion晶格。