Interface-driven topological Hall effect in SrRuO3-SrIrO3 bilayer.
Interface-driven topological Hall effect in SrRuO3-SrIrO3 bilayer.
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DOI：
10.1126/sciadv.1600304
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发表时间：
2016-07
期刊：
影响因子：
13.6
通讯作者：
Kawasaki M
中科院分区：
文献类型：
--
作者：
Matsuno J;Ogawa N;Yasuda K;Kagawa F;Koshibae W;Nagaosa N;Tokura Y;Kawasaki M
电子输运测量揭示了在高质量氧化物界面处形成的涡旋自旋织构，skyrmions。电子输运与磁性的结合多年来一直受到人们的关注。其中，最近发现的拓扑霍尔效应（THE）源于标量自旋手征，即自旋对向的立体角。发现THE是探测Dzyaloshinskiii-Moriya（DM）相互作用和随之而来的磁skyrmions的一个有前途的工具。这种相互作用产生于破缺的反转对称性，因此可以人为地在界面处引入;这个概念最近在金属多层膜中得到了验证。然而，很少有人试图通过电子传输来研究这种DM在界面处的相互作用。通过外延氧化物界面的制备，阐明了输运性质与界面DM相互作用的耦合关系。我们观察到在外延双层铁磁SrRuO 3和顺磁SrIrO 3组成的温度和磁场在一个很宽的区域。THE的大小迅速降低与SrRuO 3的厚度，这表明界面DM相互作用起着重要的作用。这种相互作用有望实现10 nm大小的Néel型磁性skyrmion。目前的研究结果表明，高质量的氧化物界面使我们能够调整有效的DM相互作用，这可能是迈向未来拓扑电子学的一步。
Electronic transport measurements reveal the formation of swirling spin textures, skyrmions, at high-quality oxide interface. Electron transport coupled with magnetism has attracted attention over the years. Among them, recently discovered is topological Hall effect (THE), originating from scalar spin chirality, that is, the solid angle subtended by the spins. THE is found to be a promising tool for probing the Dzyaloshinskii-Moriya (DM) interaction and consequent magnetic skyrmions. This interaction arises from broken inversion symmetry and hence can be artificially introduced at interface; this concept is lately verified in metal multilayers. However, there are few attempts to investigate such DM interaction at interface through electron transport. We clarified how the transport properties couple with interface DM interaction by fabricating the epitaxial oxide interface. We observed THE in epitaxial bilayers consisting of ferromagnetic SrRuO3 and paramagnetic SrIrO3 over a wide region of both temperature and magnetic field. The magnitude of THE rapidly decreases with the thickness of SrRuO3, suggesting that the interface DM interaction plays a significant role. Such interaction is expected to realize a 10-nm-sized Néel-type magnetic skyrmion. The present results established that the high-quality oxide interface enables us to tune the effective DM interaction; this can be a step toward future topological electronics.