AI 中文总结
研究磁性狄拉克半金属候选EuMnSb₂的磁结构，解析其磁基态与2 T以下、接近Eu自旋饱和场的场诱导相变，提出平均场模型估算相关交换相互作用，揭示磁与电子拓扑的耦合机制。
AI 中文摘要
利用极化与非极化中子衍射、脉冲场X射线磁圆二色性及脉冲场磁强计，在最高30 T的磁场下研究磁性拓扑半金属EuMnSb₂的磁结构。确定了Eu和Mn亚晶格的零场磁结构，发现施加2 T以下磁场诱导的磁相变仅对应Eu自旋的磁序变化，未检测到Mn自旋序的可观测扰动；在接近Eu自旋饱和场的磁场处还观测到额外磁相变。提出平均场模型，该模型可描述磁行为的关键特征，使我们能估算主导的Eu-Eu和Eu-Mn交换相互作用，这些相互作用是磁有序与电子拓扑耦合的成因。
英文摘要
The magnetic structure of a magnetic topological semimetal EuMnSb$_2$ is investigated in fields up to 30 T using polarized and unpolarized neutron diffraction, pulsed-field x-ray magnetic circular dichroism and pulsed-field magnetometry. We determine the zero-field magnetic structures of the Eu and Mn sublattices, and find that magnetic transitions induced by applied fields below 2 T correspond to changes in the magnetic order of the Eu spins alone without detectable perturbation to the order of the Mn spins. An additional magnetic transition is observed at fields close to the saturation field for the Eu spins. We present a mean-field model which describes key features of the magnetic behavior and allows us to estimate the dominant Eu--Eu and Eu--Mn exchange interactions responsible for the coupling between magnetism and electronic topology.
