Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore.
Department of Materials Science & Engineering, National University of Singapore, Singapore, 117575, Singapore.
Nat Commun. 2018 Jun 8;9(1):2255. doi: 10.1038/s41467-018-04712-9.
The anomalous Hall effect, observed in conducting ferromagnets with broken time-reversal symmetry, offers the possibility to couple spin and orbital degrees of freedom of electrons in ferromagnets. In addition to charge, the anomalous Hall effect also leads to spin accumulation at the surfaces perpendicular to both the current and magnetization direction. Here, we experimentally demonstrate that the spin accumulation, subsequent spin backflow, and spin-charge conversion can give rise to a different type of spin current-related spin current related magnetoresistance, dubbed here as the anomalous Hall magnetoresistance, which has the same angular dependence as the recently discovered spin Hall magnetoresistance. The anomalous Hall magnetoresistance is observed in four types of samples: co-sputtered (FeMn )Pt, FeMn /Pt multilayer, FeMn with x = 0.17-0.65 and Fe, and analyzed using the drift-diffusion model. Our results provide an alternative route to study charge-spin conversion in ferromagnets and to exploit it for potential spintronic applications.
反常霍尔效应在时间反演对称破缺的导体中观察到,为铁磁体中电子的自旋和轨道自由度的耦合提供了可能。除了电荷之外,反常霍尔效应还会导致在垂直于电流和磁化方向的表面上产生自旋积累。在这里,我们通过实验证明,自旋积累、随后的自旋回流和自旋-电荷转换会导致一种不同类型的与自旋相关的磁电阻,我们称之为反常霍尔磁电阻,它与最近发现的自旋霍尔磁电阻具有相同的角依赖性。反常霍尔磁电阻在四种类型的样品中被观察到:共溅射的(FeMn)Pt、FeMn/Pt 多层、x=0.17-0.65 的 FeMn 和 Fe,并使用漂移-扩散模型进行了分析。我们的结果提供了一种研究铁磁体中电荷-自旋转换的替代途径,并为潜在的自旋电子学应用提供了利用途径。