论文标题
扭曲的范德华磁铁中的天空
Skyrmions in twisted van der Waals magnets
论文作者
论文摘要
通常，通过dzyaloshinskii-Moriya相互作用和外部磁场的组合，二维手性磁体中的磁性天际势稳定。在这里，我们表明，在没有外部磁场的情况下，天空也可以在扭曲的Moiré超晶格中稳定。我们的设置由在抗铁磁底物顶部扭曲的2D铁磁层组成。铁磁层和底物之间的耦合产生有效的交流交换场。当Moiré周期性和Skyrmions的长度尺度兼容时，我们发现了大部分Skyrmion晶体相。与磁场下的手性磁铁不同，Moiré超级晶格中的Skyrmions对易于轴（ISING）各向异性的稳定性增强，这对于实现Skyrmions可能是必不可少的，因为大多数Van der waals磁铁具有易于轴各向异性。
Magnetic skyrmions in 2D chiral magnets are in general stabilized by a combination of Dzyaloshinskii-Moriya interaction and external magnetic field. Here, we show that skyrmions can also be stabilized in twisted moiré superlattices in the absence of an external magnetic field. Our setup consists of a 2D ferromagnetic layer twisted on top of an antiferromagnetic substrate. The coupling between the ferromagnetic layer and the substrate generates an effective alternating exchange field. We find a large region of skyrmion crystal phase when the length scales of the moiré periodicity and skyrmions are compatible. Unlike chiral magnets under magnetic field, skyrmions in moiré superlattices show enhanced stability for the easy-axis (Ising) anisotropy which can be essential to realize skyrmions since most van der Waals magnets possess easy-axis anisotropy.
