论文标题
新型二维扭曲的双层磁体中的磁性天际晶格
Magnetic skyrmion lattices in a novel two-dimensional twisted bilayer magnet
论文作者
论文摘要
磁性天空是拓扑保护的自旋旋转顶点，由于其粒子样性质和出色的可控制性，在设备应用中有望。磁性天际已在多种材料中进行了广泛的研究，并被提议在极端的二维极限中，即在扭曲的双层CRI $ _3 $（TBCI）中存在。不幸的是，在最近的实验中，具有小扭曲角度的TBCI的磁状态是无序分布的铁磁（FM）和抗铁磁（AFM）结构域的，因此可以消除TBCIS中的疾病的方法。在这里，我们使用的是内部交换相互作用，直到第三个最近的邻居没有经验参数，并且非常准确的层间交换相互作用来研究TBCIS的磁态。我们提出了使用第一原理计算获得并存储在对称化适应的人工神经网络中的层间交换相互作用的功能。基于它们，随后的Landau-Lifshitz-Gillbert方程计算解释了TBCIS中的无序分布的FM-AFM域，其扭曲角度很小，并预测具有较大扭曲角度的TBCIS中有序分布的Skyrmions。这个新颖的二维双层磁铁可用于设计记忆设备，单色自旋波发生器和许多天际晶格。
Magnetic skyrmions are topologically protected spin swirling vertices, which are promising in device applications due to their particle-like nature and excellent controlability. Magnetic skyrmions have been extensively studied in a variety of materials and were proposed to exist in the extreme two-dimensional limit, i.e., in twisted bilayer CrI$_3$ (TBCI). Unfortunately, the magnetic states of TBCIs with small twist angles are disorderly distributed ferromagnetic (FM) and antiferromagnetic (AFM) domains in recent experiments, and thus the method to get rid of disorders in TBCIs is highly desirable. Here we use intralayer exchange interactions up to the third nearest neighbors without empirical parameters and very accurate interlayer exchange interactions to study the magnetic states of TBCIs. We propose the functions of interlayer exchange interactions obtained using first-principles calculations and stored in symmetry-adapted artificial neural networks. Based on them, the subsequent Landau-Lifshitz-Gillbert equation calculations explain the disorderly distributed FM-AFM domains in TBCIs with small twist angles and predict the orderly distributed skyrmions in TBCIs with large twist angles. This novel twisted two-dimensional bilayer magnet can be used to design memory devices, monochromatic spin wave generators and many kinds of skyrmion lattices.
