论文标题
矢量性手性$κ$驱动的拓扑相变和相关的异常霍尔电导率调谐
Vector Chirality $κ$ Driven Topological Phase Transition and the Associated Anomalous Hall Conductivity Tuning in a Non-Collinear Antiferromagnet
论文作者
论文摘要
基于第一原理电子结构计算和随后的对称性，适用于有效的低能量$ \ textbf {k.p} $理论，我们显示了矢量性手性（$κ$）的切换，在非倾斜的抗fiferromagnet（AFM）中，MN $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3半学。具体来说，我们发现$κ$的切换导致在Fermi-Level的各处散发出一个椭圆形的节点环，除了环上的一对。结果，拓扑相变为异常霍尔电导率（AHC）从零变为巨大值。此外，我们从理论上说明了手性AFM订单的受控操纵如何保持$κ$不变的偏爱在环上的异常旋转。反过来，这使我们能够通过AFM单元中的旋转集体统一旋转来调整AHC的平面内部成分。
Based on the first-principles electronic structure calculations and subsequent symmetry adapted effective low-energy $\textbf{k.p}$ theory, we show the switching of the vector chirality, $κ$, in a noncollinear antiferromagnet (AFM), Mn$_3$Sn, as an unconventional route to topological phase transition from a nodal-ring to a Weyl point semimetal. Specifically, we find that the switching of $κ$ leads to gaping out an elliptic nodal-ring everywhere at the Fermi-level except for a pair of points on the ring. As a consequence, the topological phase transition switches the anomalous Hall conductivity (AHC) from zero to a giant value. Furthermore, we theoretically demonstrate how the controlled manipulation of the chiral AFM order keeping $κ$ unaltered favors unusual rotation of Weyl-points on the ring. This in turn enables us to tune in-plane components of the AHC by a collective uniform rotations of spins in the AFM unit cell.
