论文标题
Néel-type Skyrmion晶格的稳定性对GAV $ _4 $ S $ _8 $和GAV $ _4 $ SE $ _8 $
Stability of Néel-type skyrmion lattice against oblique magnetic fields in GaV$_4$S$_8$ and GaV$_4$Se$_8$
论文作者
论文摘要
Lacunar Spinels Gav $ _4 $ S $ _8 $和GAV $ _4 $ _4 $ SE $ _8 $在Lacunar Spinels Gav $ _4 $ _4 $ s $ _8 $中的Néel-type Skyrmions的方向与其基础晶体结构的极性轴相连。在这些晶体中，存在与这些轴平行的外部施加磁场的Skyrmion晶格阶段，并承受倾斜的磁场至一定临界角。在这里，我们使用动态悬臂磁力测定法绘制了两个晶体中Skyrmion晶格相的稳定性。测得的相图重现了最近的理论模型预测的主要特征，其中包括GAV $ _4 $ SE $ _8 $的重入循环相。尽管如此，我们观察到了倾斜磁场的Skyrmion阶段更大的鲁棒性，这表明对模型可能进行了改进。除了确定散装中的循环，天际晶格和铁磁状态之间的过渡外，我们还测量了GAV $ _4 $ SE $ _8 $中的其他异常，并将它们分配到限制在极性结构域壁上的磁状态。
The orientation of Néel-type skyrmions in the lacunar spinels GaV$_4$S$_8$ and GaV$_4$Se$_8$ is tied to the polar axes of their underlying crystal structure through the Dzyaloshinskii-Moriya interaction. In these crystals, the skyrmion lattice phase exists for externally applied magnetic fields parallel to these axes and withstands oblique magnetic fields up to some critical angle. Here, we map out the stability of the skyrmion lattice phase in both crystals as a function of field angle and magnitude using dynamic cantilever magnetometry. The measured phase diagrams reproduce the major features predicted by a recent theoretical model, including a reentrant cycloidal phase in GaV$_4$Se$_8$. Nonetheless, we observe a greater robustness of the skyrmion phase to oblique fields, suggesting possible refinements to the model. Besides identifying transitions between the cycloidal, skyrmion lattice, and ferromagnetic states in the bulk, we measure additional anomalies in GaV$_4$Se$_8$ and assign them to magnetic states confined to polar structural domain walls.
