论文标题
Weyl Smimetal Smalsi中的拓扑螺旋磁
Topological spiral magnetism in the Weyl semimetal SmAlSi
论文作者
论文摘要
由于新型电荷转运现象，例如手性异常，费米弧和光钙化效应，因此对Weyl电子进行了深入研究。最近的理论工作表明，Weyl电子也可以参与磁相互作用，并且在局部矩之间的Weyl介导的间接交换耦合被认为是涉及手性电子的螺旋磁性的新机制。尽管有报道称Weyl半学中的不一致和非连接磁性顺序，但迄今为止，实际的螺旋顺序仍未被发现。在这里，我们提供了来自中子衍射，运输和热力学数据中的smalsi中Weyl介导的螺旋磁的证据。我们表明，Smalsi中的螺旋顺序是由拓扑非平凡的费米口袋和弱磁晶体趋势之间的嵌套引起的，与相关的材料（CE，PR，ND）ALSI不同，强烈的各向异性会使旋转自由旋转。我们绘制Smalsi的磁相图，并揭示可能存在拓扑磁激发的A相。通过观察A相内的拓扑厅效应来证实这一点。
Weyl electrons are intensely studied due to novel charge transport phenomena such as chiral anomaly, Fermi arcs, and photogalvanic effect. Recent theoretical works suggest that Weyl electrons can also participate in magnetic interactions, and the Weyl-mediated indirect exchange coupling between local moments is proposed as a new mechanism of spiral magnetism that involves chiral electrons. Despite reports of incommensurate and non-collinear magnetic ordering in Weyl semimetals, an actual spiral order has remained hitherto undetected. Here, we present evidence of Weyl-mediated spiral magnetism in SmAlSi from neutron diffraction, transport, and thermodynamic data. We show that the spiral order in SmAlSi results from the nesting between topologically non-trivial Fermi pockets and weak magnetocrystalline anisotropy, unlike related materials (Ce,Pr,Nd)AlSi, where a strong anisotropy prevents the spins from freely rotating. We map the magnetic phase diagram of SmAlSi and reveal an A-phase where topological magnetic excitations may exist. This is corroborated by the observation of a topological Hall effect within the A-phase.
