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

Autor: Matsuno, J., Ogawa, N., Yasuda, K., Kagawa, F., Koshibae, W., Nagaosa, N., Tokura, Y., Kawasaki, M.
Rok vydání: 2016
Předmět:
Zdroj: Sci. Adv. 2, e1600304 (2016)
Druh dokumentu: Working Paper
DOI: 10.1126/sciadv.1600304
Popis: 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 N\'{e}el-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.
Comment: 18 pages, 3 figures; revised version has been published in Sci. Adv. 2, e1600304 (2016)
Databáze: arXiv