标题： RuO₂/Py 异质结构中由界面生成的自旋流引起的磁阻 显示英文标题

标题： Interface-Generated Spin Current Induced Magnetoresistance in RuO2/Py Heterostructures

摘要： 反磁体是一种最近发现的磁性材料类别，表现出类似铁磁性的自旋分裂能带和类似反铁磁性的补偿磁有序态，吸引了下一代自旋电子学应用的极大兴趣。 二氧化钌（RuO₂）因其补偿的反平行磁有序态和强烈的自旋分裂电子能带而成为一种有前景的反磁体候选材料。 然而，近期的实验和理论报告也表明，RuO₂ 在基态下可能是非磁性的，这凸显了对其磁性特征进行更深入研究的必要性。 具体而言，（100）取向的 RuO₂ 薄膜预计会生成与奈尔矢量平行的横向自旋极化的自旋电流。 在这里，我们研究了外延 RuO₂/坡莫合金（Py）异质结构中的磁电输运，以检查在这种系统中产生的自旋霍尔磁阻和界面效应。 我们的测量结果显示，对于垂直于电荷电流方向的磁场方向变化，存在显著的负角度依赖性磁阻。 详细的温度、磁场和晶体取向依赖性测量表明，在 RuO₂/Py 界面处生成的界面自旋电流（IGSC）主导了观察到的磁阻。 这表明强界面效应比 RuO₂ 的可能反磁贡献更为突出。 我们的结果表明，界面生成的自旋电流的作用至关重要，不应忽视在反磁性系统的研究中。 在这个方向上的关键一步是区分界面效应和反磁效应的贡献。 了解反磁性影响下的界面贡献对于推进基于 RuO₂ 的自旋电子存储和传感应用至关重要。 显示英文摘要

摘要： Altermagnets, a recently discovered class of magnetic materials exhibiting ferromagnetic-like spin-split bands and antiferromagnetic-like compensated magnetic order, have attracted significant interest for next-generation spintronic applications. Ruthenium dioxide (RuO2) has emerged as a promising altermagnetic candidate due to its compensated antiparallel magnetic order and strong spin-split electronic bands. However, recent experimental and theoretical reports also suggest that RuO2 may be non-magnetic in its ground state, underscoring the need for deeper investigations into its magnetic character. Specifically, the (100)-oriented RuO2 films are expected to generate spin currents with transverse spin polarization parallel to the N\'eel vector. Here, we investigate magnetotransport in epitaxial RuO2/Permalloy (Py) heterostructures to examine spin Hall magnetoresistance and interfacial effects generated in such systems. Our measurements reveal a pronounced negative angular-dependent magnetoresistance for variation of magnetic field direction perpendicular to the charge current direction. Detailed temperature-, magnetic field-, and crystallographic orientation-dependent measurements indicate that interface-generated spin current (IGSC) at the RuO2/Py interface predominantly governs the observed magnetoresistance. This shows that strong interface effects dominate over possible altermagnetic contributions from RuO2. Our results show that the role of interface-generated spin currents is crucial and should not be overlooked in studies of altermagnetic systems. A critical step in this direction is disentangling interfacial from altermagnetic contributions. The insight into interfacial contributions from altermagnetic influences is essential for the advancement of RuO2 based spintronic memory and sensing applications.