论文标题
铁磁COS2中的Weyl-Fermions，Fermi-Arcs和少数型载体
Weyl-fermions, Fermi-arcs, and minority-spin carriers in ferromagnetic CoS2
论文作者
论文摘要
由于其流动的铁磁性和半金属的潜力，过去对黄铁矿化合物COS2进行了深入研究，这使其成为旋转型应用的有希望的材料。但是，它的电子结构仍然很少理解。在这里，我们使用互补的散装和表面敏感的角度分辨光电光谱和AB-Initio计算，以提供其带状结构的完整图片。我们在Fermi级别发现了Weyl-cones，它以新的方式呈现COS2，是最近发现的一类磁性金属类的罕见成员。我们直接观察到将Weyl节点连接起来的拓扑Fermi-arc表面状态，这将通过修改其在接口处的自旋极化来影响COS2作为自旋注射器的性能。此外，我们第一次能够直接观察到布里鲁因区域角落的少数旋转散装电子口袋，这证明COS2不能是真正的半金属。除了解决COS2中关于半金属性的长期争论之外，我们的结果还提供了一个很好的例子，说明了磁性材料的拓扑如何影响它们在Spintronic应用中的使用。
The pyrite compound CoS2 has been intensively studied in the past due to its itinerant ferromagnetism and potential for half-metallicity, which make it a promising material for spintronic applications. However, its electronic structure remains only poorly understood. Here we use complementary bulk- and surface-sensitive angle-resolved photoelectron spectroscopy and ab-initio calculations to provide a complete picture of its band structure. We discover Weyl-cones at the Fermi-level, which presents CoS2 in a new light as a rare member of the recently discovered class of magnetic topological metals. We directly observe the topological Fermi-arc surface states that link the Weyl-nodes, which will influence the performance of CoS2 as a spin-injector by modifying its spin-polarization at interfaces. Additionally, we are for the first time able to directly observe a minority-spin bulk electron pocket in the corner of the Brillouin zone, which proves that CoS2 cannot be a true half-metal. Beyond settling the longstanding debate about half-metallicity in CoS2, our results provide a prime example of how the topology of magnetic materials can affect their use in spintronic applications.
