论文标题
拓扑厅效应中的相干反向散射
Coherent backscattering in the topological Hall effect
论文作者
论文摘要
近年来,电子传输和磁性之间的相互作用引起了很大的关注,主要是由操纵磁性自由度的策略,例如自旋轨道扭矩和域壁运动。在该领域内,源自标量自旋手性的拓扑厅效应是由真实空间不均匀磁纹理引起的带间量子相干性的一个例子,其大小取决于绕组数和手性旋转特征,这些特征确定了系统的总拓扑电荷。值得注意的是,自发现发现以来的二十年中,没有关于拓扑厅效应的量子校正的研究。在这里,我们将表明,与普通的霍尔效应不同,自旋纹理引起的不均匀磁化将在动力学方程中提供其他散射项,从而导致对拓扑厅电阻率的量子校正。我们专注于弱定位最强的2D系统,并确定库赛和动力学方程的复杂梯度校正。尽管目前已知的材料中对拓扑厅效应的弱定位校正并不大,但我们表明它在稀磁半导体中可以观察到它。我们的理论结果将刺激对拓扑厅效应的实验,并填补较弱的定位校正横向运输的理论知识差距。
The mutual interplay between electron transport and magnetism has attracted considerable attention in recent years, primarily motivated by strategies to manipulate magnetic degrees of freedom electrically, such as spin-orbit torques and domain wall motion. Within this field the topological Hall effect, which originates from scalar spin chirality, is an example of inter-band quantum coherence induced by real-space inhomogeneous magnetic textures, and its magnitude depends on the winding number and chiral spin features that establish the total topological charge of the system. Remarkably, in the two decades since its discovery, there has been no research on the quantum correction to the topological Hall effect. Here we will show that, unlike the ordinary Hall effect, the inhomogeneous magnetization arising from the spin texture will give additional scattering terms in the kinetic equation, which result in a quantum correction to the topological Hall resistivity. We focus on 2D systems, where weak localization is strongest, and determine the complicated gradient corrections to the Cooperon and kinetic equation. Whereas the weak localization correction to the topological Hall effect is not large in currently known materials, we show that it is experimentally observable in dilute magnetic semiconductors. Our theoretical results will stimulate experiments on the topological Hall effect and fill the theoretical knowledge gap on weak localization corrections to transverse transport.