Interface-driven topological Hall effect in SrRuO${}_3$-SrIrO${}_3$ bilayer

Abstract

Electron transport coupled with magnetism has attracted attention over the years as exemplified in anomalous Hall effect due to a Berry phase in momentum space. Another type of unconventional Hall effect -- topological Hall effect, originating from the real-space Berry phase, has recently become of great importance in the context of magnetic skyrmions. We have observed topological Hall effect in bilayers consisting of ferromagnetic SrRuO${}_3$ and paramagnetic SrIrO${}_3$ over a wide region of both temperature and magnetic field. The topological term rapidly decreases with the thickness of SrRuO${}_3$, ending up with the complete disappearance at 7 unit cells of SrRuO${}_3$. Combined with model calculation, we concluded that the topological Hall effect is driven by interface Dzyaloshinskii-Moriya interaction, which is caused by both the broken inversion symmetry and the strong spin-orbit coupling of SrIrO${}_3$. Such interaction is expected to realize the Néel-type magnetic skyrmion, of which size is estimated to be $\sim$10 nm from the magnitude of topological Hall resistivity. The results established that the high-quality oxide interface enables us to tune the chirality of the system; this can be a step towards the future topological electronics.

18 pages, 3 figures; revised version has been published in Sci. Adv. 2, e1600304 (2016)

References in corpus (4)

• Spontaneous Skyrmion Ground States in Magnetic Metals
• Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
• Direct observation of the Dzyaloshinskii-Moriya interaction in a Pt/Co/Ni film
• Memory functions of magnetic skyrmions

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• Tuning Perpendicular Magnetic Anisotropy by Oxygen Octahedral Rotations in (La${}_{1-x}$Sr${}_x$MnO${}_3$)/(SrIrO${}_3$) Superlattices
• Interpretation of experimental evidence of the topological Hall effect
• Unconventional Topological Hall Effect in Skyrmion Crystals Caused by the Topology of the Lattice
• Charge transfer in iridate-manganite superlattices
• Evidence of a topological Hall effect in Eu${}_{1-x}$Sm${}_x$TiO${}_3$
• Observation of Topological Hall Effect and Signature of Room Temperature Antiskyrmions in Mn-Ni-Ga D2d Heusler magnets
• Interface induced exchange bias effect in La${}_{0.67}$Sr${}_{0.33}$MnO${}_3$/SrIrO${}_3$ multilayer
• Topological Hall effect in bulk ferromagnet Cr${}_2$Te${}_3$ embedded with black-phosphorus-like bismuth nanosheets
• Prediction of topological Hall effect in a driven magnetic domain wall