标题： 反常的局部磁场温度依赖性在反铁磁MnTe中 显示英文标题

标题： Anomalous temperature dependence of local magnetic fields in altermagnetic MnTe

摘要： 反磁体是一种新型的磁性系统，在没有净磁矩的情况下具有自旋极化的电能带结构，这在潜在器件应用中展现出令人兴奋的前景。 六方 MnTe 是一种典型的反磁体，其表现出最符合理论预测的性质，包括在没有净磁化的情况下出现反常霍尔效应，以及在电子能带结构中的强反磁体诱导自旋分裂。 在此我们展示了 MnTe 单晶的穆子自旋光谱测量。 在室温以下，我们观察到穆子自旋去极化中的显著异常，以及在无外加磁场情况下第二非比例内部场的出现。 这些发现表明在$T\simeq250$ K 左右磁结构发生了变化，这与其他报道的性质变化相吻合，例如输运性质。 显示英文摘要

摘要： Altermagnets are a novel type of magnetic system that has a spin-polarised electric band structure in the absence of a net magnetic moment, leading to exciting prospects in potential device applications. Hexagonal MnTe, a prototypical altermagnet, has arguably shown the most properties consistent with theoretical predictions, including an anomalous Hall effect despite no net magnetisation, and strong altermagnet-induced spin splitting in the electronic band structure. Here we present muon-spin spectroscopy measurements of a single crystal of MnTe. Below room temperature we observe pronounced anomalies in the muon-spin depolarisation, as well as the onset of a second, non-proportional internal field in the absence of an applied field. These findings point to a change in the magnetic structure around $T\simeq250$ K, which coincides with other changes in reported properties, such as transport.