Abstract
Magnetic skyrmions are topologically robust nanoscale spin textures that can be manipulated with low current densities and are thus potential information carriers in future spintronic devices. Skyrmions have so far been mainly observed in metallic films, which suffer from ohmic losses and therefore high energy dissipation. Magnetic insulators could provide a more energy-efficient skyrmionic platform due to their low damping and absence of Joule heat loss. However, skyrmions have previously been observed in an insulating compound (Cu2OSeO3) only at cryogenic temperatures, where they are stabilized by a bulk Dzyaloshinskii–Moriya interaction. Here, we report the observation of the topological Hall effect—a signature of magnetic skyrmions—at above room temperature in a bilayer heterostructure composed of a magnetic insulator (thulium iron garnet, Tm3Fe5O12) in contact with a metal (Pt). The dependence of the topological Hall effect on the in-plane bias field and the thickness of the magnetic insulator suggest that the magnetic skyrmions are stabilized by the interfacial Dzyaloshinskii–Moriya interaction. By varying the temperature of the system, we can tune its magnetic anisotropy and obtain skyrmions in a large window of external magnetic field and enhanced stability of skyrmions in the easy-plane anisotropy regime.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.
References
Malozemoff, A. P. & Slonczewski, J. C. Magnetic Domain Walls in Bubble Materials (Academic Press, 1979).
Fert, A., Cros, V. & Sampaio, J. Skyrmions on the track. Nat. Nanotechnol. 8, 152–156 (2013).
Moreau-Luchaire, C. et al. Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature. Nat. Nanotechnol. 11, 444–448 (2016).
Woo, S. et al. Observation of room-temperature magnetic skyrmions and their current-driven dynamics in ultrathin metallic ferromagnets. Nat. Mater. 15, 501–506 (2016).
Heinze, S. et al. Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions. Nat. Phys. 7, 713–718 (2011).
Jiang, W. et al. Blowing magnetic skyrmion bubbles. Science 349, 283–286 (2015).
Muhlbauer, S. et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).
Seki, S., Yu, X. Z., Ishiwata, S. & Tokura, Y. Observation of skyrmions in a multiferroic material. Science 336, 198–201 (2012).
Nagaosa, N. & Tokura, Y. Topological properties and dynamics of magnetic skyrmions. Nat. Nanotechnol. 8, 899–911 (2013).
Yu, G. et al. Room-temperature skyrmion shift device for memory application. Nano Lett. 17, 261–268 (2017).
Yu, G. et al. Room-temperature creation and spin–orbit torque manipulation of skyrmions in thin films with engineered asymmetry. Nano Lett. 16, 1981–1988 (2016).
Jonietz, F. et al. Spin transfer torques in MnSi at ultralow current densities. Science 330, 1648–1651 (2010).
Upadhyaya, P., Yu, G., Amiri, P. K. & Wang, K. L. Electric-field guiding of magnetic skyrmions. Phys. Rev. B 92, 134411 (2015).
Neubauer, A. et al. Topological Hall effect in the a phase of MnSi. Phys. Rev. Lett. 102, 186602 (2009).
Zang, J., Mostovoy, M., Han, J. H. & Nagaosa, N. Dynamics of skyrmion crystals in metallic thin films. Phys. Rev. Lett. 107, 136804 (2011).
Kajiwara, Y. et al. Transmission of electrical signals by spin–wave interconversion in a magnetic insulator. Nature 464, 262–266 (2010).
Schütte, C. & Garst, M. Magnon–skyrmion scattering in chiral magnets. Phys. Rev. B 90, 094423 (2014).
Nakata, K., Klinovaja, J. & Loss, D. Magnonic quantum Hall effect and Wiedemann–Franz law. Phys. Rev. B 95, 125429 (2017).
Ochoa, H., Kim, S. K. & Tserkovnyak, Y. Topological spin-transfer drag driven by skyrmion diffusion. Phys. Rev. B 94, 024431 (2016).
Kong, L. & Zang, J. Dynamics of an insulating skyrmion under a temperature gradient. Phys. Rev. Lett. 111, 067203 (2013).
Onose, Y., Okamura, Y., Seki, S., Ishiwata, S. & Tokura, Y. Observation of magnetic excitations of skyrmion crystal in a helimagnetic insulator Cu2OSeO3. Phys. Rev. Lett. 109, 037603 (2012).
Mochizuki, M. et al. Thermally driven ratchet motion of a skyrmion microcrystal and topological magnon Hall effect. Nat. Mater. 13, 241–246 (2014).
Pollath, S. et al. Dynamical defects in rotating magnetic skyrmion lattices. Phys. Rev. Lett. 118, 207205 (2017).
Yu, X. et al. Magnetic stripes and skyrmions with helicity reversals. Proc. Natl Acad. Sci. USA 109, 8856–8860 (2012).
Tang, C. et al. Anomalous Hall hysteresis in Tm3Fe5O12/Pt with strain-induced perpendicular magnetic anisotropy. Phys. Rev. B 94, 140403(R) (2016).
Chen, Y.-T. et al. Theory of spin Hall magnetoresistance. Phys. Rev. B 87, 144411 (2013).
Huang, S. Y. et al. Transport magnetic proximity effects in platinum. Phys. Rev. Lett. 109, 107204 (2012).
Yasuda, K. et al. Geometric Hall effects in topological insulator heterostructures. Nat. Phys. 12, 555–559 (2016).
Matsuno, J. et al. Interface-driven topological Hall effect in SrRuO3–SrIrO3 bilayer. Sci. Adv. 2, e1600304 (2016).
Pai, C.-F., Mann, M., Tan, A. J. & Beach, G. S. D. Determination of spin torque efficiencies in heterostructures with perpendicular magnetic anisotropy. Phys. Rev. B 93, 144409 (2016).
Bogdanov, A. & Hubert, A. Thermodynamically stable magnetic vortex states in magnetic crystals. J. Magn. Magn. Mater. 138, 255–269 (1994).
Soumyanarayanan, A. et al. Tunable room-temperature magnetic skyrmions in Ir/Fe/Co/Pt multilayers. Nat. Mater. 16, 898–904 (2017).
Quindeau, A. et al. Tm3Fe5O12/Pt heterostructures with perpendicular magnetic anisotropy for spintronic applications. Adv. Electron. Mater. 3, 1600376 (2017).
Banerjee, S., Rowland, J., Erten, O. & Randeria, M. Enhanced stability of skyrmions in two-dimensional chiral magnets with Rashba spin–orbit coupling. Phys. Rev. X 4, 031045 (2014).
Cho, J. et al. Thickness dependence of the interfacial Dzyaloshinskii–Moriya interaction in inversion symmetry broken systems. Nat. Commun. 6, 7635 (2015).
Suzuki, T. et al. Large anomalous Hall effect in a half-Heusler antiferromagnet. Nat. Phys. 12, 1119–1123 (2016).
Takahashi, K. S. et al. Anomalous Hall effect derived from multiple Weyl nodes in high-mobility EuTiO3 films. Sci. Adv. 4, eaar7880 (2018).
Taguchi, Y., Oohara, Y., Yoshizawa, H., Nagaosa, N. & Tokura, Y. Spin chirality, berry phase and anomalous Hall effect in a frustrated ferromagnet. Science 291, 2573–2576 (2001).
Maccariello, D. et al. Electrical detection of single magnetic skyrmions in metallic multilayers at room temperature. Nat. Nanotechnol. 13, 233–237 (2018).
Zeissler, K. et al. Discrete Hall resistivity contribution from Neel skyrmions in multilayer nanodiscs. Nat. Nanotechnol. 13, 1161–1166 (2018).
Raju, M. et al. The evolution of skyrmions in Ir/Fe/Co/Pt multilayers and their topological Hall signature. Nat. Commun. 10, 696 (2019).
Avci, C. O. et al. Interface-driven chiral magnetism and current-driven domain walls in insulating magnetic garnets. Nat. Nanotechnol. https://doi.org/10.1038/s41565-019-0421-2 (2019).
Vélez, S. et al. High-speed domain wall racetracks in a magnetic insulator. Preprint at https://arxiv.org/abs/1902.05639 (2019).
Acknowledgements
The authors thank J. Li for help with thin film preparation, C. Zheng and A. Navabi for assistance with device fabrication and Y. Liu for helpful discussions on micromagnetic simulations. Q.S. thanks P. Zhang for assistance with loop shift measurements. This work is supported partially by Spins and Heat in Nanoscale Electronic Systems (SHINES), an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award no. DE-SC0012670. The authors acknowledge support from the Army Research Office Multidisciplinary University Research Initiative (MURI) programme under grants W911NF-16-1-0472 and W911NF-15-1-10561. The authors at UCLA are also partially supported by the National Science Foundation (ECCS 1611570) and by C-SPIN and FAME, two of six centres of STARnet, a Semiconductor Research Corporation programme sponsored by MARCO and DARPA. Y.T. is supported by the US DOE, BES, under award no. DE-SC0012190.
Author information
Authors and Affiliations
Contributions
Q.S., G.Y. and K.L.W. conceived the idea. Q.S. carried out the transport measurements. Y.L. and C.T. grew the TmIG/Pt thin films. X.C. fabricated the Hall bar devices. S.K.K. and Q.S. performed the analytical calculations. Q.S. performed the micromagnetic simulations. All authors contributed to the discussion of the results. Q.S. and K.L.W. wrote the manuscript with help from other authors.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Supplementary Information
Supplementary Notes 1–8 and Supplementary Figs. 1–15
Rights and permissions
About this article
Cite this article
Shao, Q., Liu, Y., Yu, G. et al. Topological Hall effect at above room temperature in heterostructures composed of a magnetic insulator and a heavy metal. Nat Electron 2, 182–186 (2019). https://doi.org/10.1038/s41928-019-0246-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41928-019-0246-x
This article is cited by
-
Machine learning assisted derivation of minimal low-energy models for metallic magnets
npj Computational Materials (2023)
-
Spintronics intelligent devices
Science China Physics, Mechanics & Astronomy (2023)
-
Progress on elliptical magnetic skyrmions
Rare Metals (2023)
-
Challenges in identifying chiral spin textures via the topological Hall effect
Communications Materials (2022)
-
Current-driven dynamics and ratchet effect of skyrmion bubbles in a ferrimagnetic insulator
Nature Nanotechnology (2022)