Skyrmions in twisted van der Waals magnets
Skyrmions in twisted van der Waals magnets
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DOI：
10.1103/physrevb.103.l140406
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发表时间：
2021-04-13
影响因子：
3.7
通讯作者：
Erten, Onur
中科院分区：
文献类型：
--
作者：
Akram, Muhammad;Erten, Onur
在二维（2D）手性磁体中的磁skyrmions通常通过Dzyaloshinskiii-Moriya相互作用和外部磁场的组合来稳定。在这里，我们表明，Skyrmions也可以稳定在扭曲的莫尔超晶格与Dzyaloshinskiii-Moriya相互作用的情况下，外部磁场。我们的设置包括一个2D铁磁层扭曲的反铁磁衬底的顶部。铁磁层和衬底之间的耦合产生有效的交变交换场。我们发现一个大区域的Skyrmion晶体相时，莫尔周期和Skyrmion的长度尺度是兼容的。与磁场下的手征磁体不同，莫尔超晶格中的Skyrmions显示出易轴（Ising）各向异性的增强的稳定性，这对于实现Skyrmions是必不可少的，因为大多数货车德瓦尔斯磁体具有易轴各向异性。
Magnetic skyrmions in two-dimensional (2D) chiral magnets are often stabilized by a combination of a Dzyaloshinskii-Moriya interaction and an external magnetic field. Here, we show that skyrmions can also be stabilized in twisted moire superlattices with a Dzyaloshinskii-Moriya interaction 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 the skyrmion crystal phase when the length scales of the moire periodicity and skyrmions are compatible. Unlike chiral magnets under a magnetic field, skyrmions in moire superlattices show an 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.