论文标题
拓扑电子结构和非晶格六角形材料中的Weyl点
Topological electronic structure and Weyl points in nonsymmorphic hexagonal materials
论文作者
论文摘要
使用拓扑结构理论分析我们表明，在带状固定晶格中的非晶状体对称性操作在带螺杆结构的高对称线处强化了Weyl点。核心代理理论和连通性群体理论表明，Weyl点是由手风琴状和类似沙漏的分散关系在带状横梁产生的。这些Weyl点在弱扰动上是稳定的，并且受螺钉旋转对称性的保护。根据第一原理的计算，我们发现拓扑预测的能量分散关系与实际六边形材料之间达成了完全一致的一致性。拓扑电荷（手性）和浆果曲率计算表明，在4D转型金属三氟体（例如AGF3和AUF3）中，Weyl点和节点线的同时形成。此外，由于电子结构中强的旋转轨道耦合和多个Weyl-Point横梁，发现了较大的固有自旋式电导率。这些材料可用于在更节能的自旋设备中的自旋/电荷转换。
Using topological band theory analysis we show that the nonsymmorphic symmetry operations in hexagonal lattices enforce Weyl points at the screw-invariant high-symmetry lines of the band structure. The corepresentation theory and connectivity group theory show that Weyl points are generated by band crossings in accordion-like and hourglass-like dispersion relations. These Weyl points are stable against weak perturbations and are protected by the screw rotation symmetry. Based on first-principles calculations we found a complete agreement between the topological predicted energy dispersion relations and real hexagonal materials. Topological charge (chirality) and Berry curvature calculations show the simultaneous formation of Weyl points and nodal-lines in 4d transition-metal trifluorides such as AgF3 and AuF3. Furthermore, a large intrinsic spin-Hall conductivity was found due to the combined strong spin-orbit coupling and multiple Weyl-point crossings in the electronic structure. These materials could be used to the spin/charge conversion in more energy-efficient spintronic devices.
