标题： 基于钴的具有高热力学稳定性的磁性外尔半金属 显示英文标题

标题： Cobalt-Based Magnetic Weyl Semimetals with High-Thermodynamic Stabilities

摘要： 实验确定Co3Sn2S2是第一个磁性外尔半金属（MWSM）。 使用基于全局优化方法的第一性原理计算，我们研究了钴（Co基的尖晶石结构和合金，Co3MM-X2（M/M-=Ge，Sn，Pb，X=S，Se，Te）的结构稳定性和拓扑电子性质，并识别出具有新外尔相的新稳定结构。 使用紧束缚模型，我们首次揭示了钴基尖晶石结构中节点线的物理起源是不同Kagome层中钴原子之间的层间耦合，而外尔点的数量及其类型主要由钴与金属原子（Sn、Ge和Pb）之间的相互作用决定。 Co3SnPbS2合金表现出两种不同的拓扑相，这取决于锡和铅原子的相对位置：一种是三维量子反常霍尔金属，另一种是具有异常霍尔电导率（约1290）的磁性外尔半金属相，其值大于Co2Sn2S2的异常霍尔电导率。 我们的工作揭示了钴基尖晶石结构中外尔费米子的物理机制，并提出了具有高热稳定性的新型拓扑量子态。 显示英文摘要

摘要： Experiments identified Co3Sn2S2 as the first magnetic Weyl semimetal (MWSM). Using first-principles calculation with a global optimization approach, we explore the structural stabilities and topological electronic properties of cobalt (Co-based shandite and alloys, Co3MM-X2 (M/M-=Ge, Sn, Pb, X=S, Se, Te), and identify new stable structures with new Weyl phases. Using a tight-binding model, for the first time, we reveal that the physical origin of the nodal lines of a Co-based shandite structure is the interlayer coupling between Co atoms in different Kagome layers, while the number of Weyl points and their types are mainly governed by the interaction between Co and the metal atoms, Sn, Ge, and Pb. The Co3SnPbS2 alloy exhibits two distinguished topological phases, depending on the relative positions of the Sn and Pb atoms: a three-dimensional quantum anomalous Hall metal, and a MWSM phase with anomalous Hall conductivity (~1290) that is larger than that of Co2Sn2S2. Our work reveals the physical mechanism of the origination of Weyl fermions in Co-based shandite structures and proposes new topological quantum states with high thermal stability.