论文标题
异常的大厅电阻率和可能的拓扑厅效果
Anomalous Hall resistivity and possible topological Hall effect in the EuAl$_4$ antiferromagnet
论文作者
论文摘要
我们报告了在$ _4 $的单晶中观察到异常大厅电阻率，一种中心对称四方化合物，该化合物表现出共存的抗fiferromagnetic（AFM）和电荷密度 - 波（CDW）订单（CDW）订单，订单在$ t_ \ t_ \ mathrm {N} \ sim 15.6 $ k and $ t_ sim $ k和$ t_ cd， 分别。在AFM状态下，当沿$ C $轴方向应用磁场时，Eual $ _4 $进行一系列的元磁过渡。在此田间范围内，我们观察到大厅电阻率的清晰驼峰样异常，代表了异常大厅电阻率的一部分。通过考虑不同的情况，我们得出结论，这种类似驼峰的特征很可能是拓扑厅效应的表现，通常发生在已知具有非平凡拓扑旋转纹理的非中心对称材料中。鉴于这种情况，Eual $ _4 $将代表一个罕见的情况，在这种情况下，拓扑厅效应不仅在中心对称结构中产生，而且还与CDW订单共存。
We report the observation of anomalous Hall resistivity in single crystals of EuAl$_4$, a centrosymmetric tetragonal compound, which exhibits coexisting antiferromagnetic (AFM) and charge-density-wave (CDW) orders with onset at $T_\mathrm{N} \sim 15.6$ K and $T_\mathrm{CDW} \sim 140$ K, respectively. In the AFM state, when the magnetic field is applied along the $c$-axis direction, EuAl$_4$ undergoes a series of metamagnetic transitions. Within this field range, we observe a clear hump-like anomaly in the Hall resistivity, representing part of the anomalous Hall resistivity. By considering different scenarios, we conclude that such a hump-like feature is most likely a manifestation of the topological Hall effect, normally occurring in noncentrosymmetric materials known to host nontrivial topological spin textures. In view of this, EuAl$_4$ would represent a rare case where the topological Hall effect not only arises in a centrosymmetric structure, but it also coexists with CDW order.
