Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

All-electric magnetization switching and Dzyaloshinskii–Moriya interaction in WTe2/ferromagnet heterostructures

Nature Nanotechnology volume 14, pages 945–949 (2019)Cite this article

Subjects

Abstract

All-electric magnetization manipulation at low power is a prerequisite for a wide adoption of spintronic devices. Materials such as heavy metals1,2,3 or topological insulators4,5 provide good charge-to-spin conversion efficiencies. They enable magnetization switching in heterostructures with either metallic ferromagnets or with magnetic insulators. Recent work suggests a pronounced Edelstein effect in Weyl semimetals due to their non-trivial band structure6,7; the Edelstein effect can be one order of magnitude stronger than it is in topological insulators or Rashba systems. Furthermore, the strong intrinsic spin Hall effect from the bulk states in Weyl semimetals can contribute to the spin current generation8. The Td phase of the Weyl semimetal WTe2 (WTe2 hereafter) possesses strong spin–orbit coupling6,9 and non-trivial band structures10 with a large spin polarization protected by time-reversal symmetry in both the surface and bulk states9,10,11. Atomically flat surfaces, which can be produced with high quality12, facilitate spintronic device applications. Here, we use WTe2 as a spin current source in WTe2/Ni81Fe19 (Py) heterostructures. We report field-free current-induced magnetization switching at room temperature. A charge current density of ~2.96 × 105 A cm−2 suffices to switch the magnetization of the Py layer. With the charge current along the b axis of the WTe2 layer, the thickness-dependent charge-to-spin conversion efficiency reaches 0.51 at 6–7 GHz. At the WTe2/Py interface, a Dzyaloshinskii–Moriya interaction (DMI) with a DMI constant of −1.78 ± 0.06 mJ m−2 induces chiral domain wall tilting. Our study demonstrates the capability of WTe2 to efficiently manipulate magnetization and sheds light on the role of the interface in Weyl semimetal/magnet heterostructures.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Raman measurements and MOKE measurements.
Fig. 2: ST-FMR measurements.
Fig. 3: Spin-orbit-torque-driven magnetization switching measurements.
Fig. 4: DW tilting induced by the interfacial DMI in WTe2/Py.

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 author upon reasonable request.

References

  1. Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. Nature 476, 189–193 (2011).

    Article  CAS  Google Scholar 

  2. Liu, L. et al. Spin-torque switching with the giant spin Hall effect of tantalum. Science 336, 555–558 (2012).

    Article  CAS  Google Scholar 

  3. Avci, C. O. et al. Current-induced switching in a magnetic insulator. Nat. Mater. 16, 309–314 (2017).

    Article  CAS  Google Scholar 

  4. Wang, Y. et al. Room temperature magnetization switching in topological insulator–ferromagnet heterostructures by spin–orbit torques. Nat. Commun. 8, 1364 (2017).

    Article  CAS  Google Scholar 

  5. Han, J. et al. Room-temperature spin–orbit torque switching induced by a topological insulator. Phys. Rev. Lett. 119, 077702 (2017).

    Article  Google Scholar 

  6. Li, Q. et al. Interference evidence for Rashba-type spin splitting on a semimetallic WTe2 surface. Phys. Rev. B 94, 115419 (2016).

    Article  Google Scholar 

  7. Johansson, A., Henk, J. & Mertig, I. Edelstein effect in Weyl semimetals. Phys. Rev. B 97, 085417 (2018).

    Article  CAS  Google Scholar 

  8. Sun, Y., Zhang, Y., Felser, C. & Yan, B. Strong intrinsic spin Hall effect in the TaAs family of Weyl semimetals. Phys. Rev. Lett. 117, 146403 (2016).

    Article  Google Scholar 

  9. Jiang, J. et al. Signature of strong spin–orbital coupling in the large nonsaturating magnetoresistance material WTe2. Phys. Rev. Lett. 115, 166601 (2015).

    Article  CAS  Google Scholar 

  10. Feng, B. et al. Spin texture in type-II Weyl semimetal WTe2. Phys. Rev. B 94, 195134 (2016).

    Article  Google Scholar 

  11. Soluyanov, A. A. et al. Type-II Weyl semimetals. Nature 527, 495–498 (2015).

    Article  CAS  Google Scholar 

  12. Lee, C.-H. et al. Tungsten ditelluride: a layered semimetal. Sci. Rep. 5, 10013 (2015).

    Article  CAS  Google Scholar 

  13. Song, Q. et al. The polarization-dependent anisotropic Raman response of few-layer and bulk WTe2 under different excitation wavelengths. RSC Adv. 6, 103830 (2016).

    Article  CAS  Google Scholar 

  14. Bayreuther, G., Premper, J., Sperl, M. & Sander, D. Uniaxial magnetic anisotropy in Fe/GaAs(001): role of magnetoelastic interactions. Phys. Rev. B 86, 054418 (2012).

    Article  Google Scholar 

  15. Liu, L., Moriyama, T., Ralph, D. & Buhrman, R. Spin-torque ferromagnetic resonance induced by the spin Hall effect. Phys. Rev. Lett. 106, 036601 (2011).

    Article  Google Scholar 

  16. Mellnik, A. et al. Spin-transfer torque generated by a topological insulator. Nature 511, 449–451 (2014).

    Article  CAS  Google Scholar 

  17. Wang, Y. et al. Topological surface states originated spin–orbit torques in Bi2Se3. Phys. Rev. Lett. 114, 257202 (2015).

    Article  Google Scholar 

  18. Das, P. K. et al. Layer-dependent quantum cooperation of electron and hole states in the anomalous semimetal WTe2. Nat. Commun. 7, 10847 (2016).

    Article  CAS  Google Scholar 

  19. Slonczewski, J. C. Current-driven excitation of magnetic multilayers. J. Magn. Magn. Mater. 159, L1–L7 (1996).

    Article  CAS  Google Scholar 

  20. Wang, Z., Li, H., Guo, X., Ho, W. & Xie, M. Growth characteristics of topological insulator Bi2Se3 films on different substrates. J. Cryst. Growth 334, 96–102 (2011).

    Article  CAS  Google Scholar 

  21. MacNeill, D. et al. Control of spin–orbit torques through crystal symmetry in WTe2/ferromagnet bilayers. Nat. Phys. 13, 300–305 (2017).

    Article  CAS  Google Scholar 

  22. Shao, Q. et al. Strong Rashba–Edelstein effect-induced spin–orbit torques in monolayer transition metal dichalcogenide/ferromagnet bilayers. Nano Lett. 16, 7514–7520 (2016).

    Article  CAS  Google Scholar 

  23. Zhang, W. et al. Research update: spin transfer torques in permalloy on monolayer MoS2. APL Mater. 4, 032302 (2016).

    Article  Google Scholar 

  24. Guimaraes, M. H., Stiehl, G. M., MacNeill, D., Reynolds, N. D. & Ralph, D. C. Spin–orbit torques in NbSe2/permalloy bilayers. Nano Lett. 18, 1311–1316 (2018).

    Article  CAS  Google Scholar 

  25. Viret, M., Vanhaverbeke, A., Ott, F. & Jacquinot, J.-F. Current induced pressure on a tilted magnetic domain wall. Phys. Rev. B 72, 140403 (2005).

    Article  Google Scholar 

  26. Ryu, K.-S., Thomas, L., Yang, S.-H. & Parkin, S. S. Current induced tilting of domain walls in high velocity motion along perpendicularly magnetized micron-sized Co/Ni/Co racetracks. Appl. Phys. Express 5, 093006 (2012).

    Article  Google Scholar 

  27. Boulle, O. et al. Domain wall tilting in the presence of the Dzyaloshinskii–Moriya interaction in out-of-plane magnetized magnetic nanotracks. Phys. Rev. Lett. 111, 217203 (2013).

    Article  CAS  Google Scholar 

  28. Thiaville, A., Rohart, S., Jué, É., Cros, V. & Fert, A. Dynamics of Dzyaloshinskii domain walls in ultrathin magnetic films. Europhys. Lett. 100, 57002 (2012).

    Article  Google Scholar 

  29. Tretiakov, O. A. & Abanov, A. Current driven magnetization dynamics in ferromagnetic nanowires with a Dzyaloshinskii–Moriya interaction. Phys. Rev. Lett. 105, 157201 (2010).

    Article  CAS  Google Scholar 

  30. Wang, W. et al. Magnon-driven domain-wall motion with the Dzyaloshinskii–Moriya interaction. Phys. Rev. Lett. 114, 087203 (2015).

    Article  Google Scholar 

  31. Di, K. et al. Direct observation of the Dzyaloshinskii–Moriya interaction in a Pt/Co/Ni film. Phys. Rev. Lett. 114, 047201 (2015).

    Article  Google Scholar 

  32. Belmeguenai, M. et al. Interfacial Dzyaloshinskii–Moriya interaction in perpendicularly magnetized Pt/Co/AlOx ultrathin films measured by Brillouin light spectroscopy. Phys. Rev. B 91, 180405 (2015).

    Article  Google Scholar 

  33. Vansteenkiste, A. et al. The design and verification of MuMax3. AIP Adv. 4, 107133 (2014).

    Article  Google Scholar 

Download references

Acknowledgements

This research was supported by the National Research Foundation (NRF), Prime Minister’s Office, Singapore, under its Competitive Research Programme (CRP award no. NRFCRP12-2013-01) and SpOT-LITE programme (A*STAR Grant no. A18A6b0057) through RIE2020 funds from Singapore.

Author information

Author notes

  1. These authors contributed equally: Shuyuan Shi, Shiheng Liang.

Authors and Affiliations

  1. Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore

    Shuyuan Shi, Shiheng Liang, Zhifeng Zhu, Kaiming Cai, Shawn D. Pollard, Yi Wang, Qisheng Wang, Pan He, Jiawei Yu, Gengchiau Liang & Hyunsoo Yang

  2. Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore

    Shuyuan Shi, Junyong Wang, Goki Eda & Hyunsoo Yang

  3. Department of Physics, National University of Singapore, Singapore, Singapore

    Junyong Wang & Goki Eda

  4. Department of Chemistry, National University of Singapore, Singapore, Singapore

    Goki Eda

Authors
  1. Shuyuan Shi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Shiheng Liang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Zhifeng Zhu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Kaiming Cai
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Shawn D. Pollard
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Yi Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Junyong Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Qisheng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Pan He
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Jiawei Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Goki Eda
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Gengchiau Liang
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Hyunsoo Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

S.S., S.L. and H.Y. conceived and designed the experiments. S.S. and S.L. performed the device fabrications and measurements. Z.Z. and G.L. calculated the spatial DMI field and performed macrospin simulations. K.C., S.D.P. and S.S. performed the micromagnetic simulations. S.S. and Y.W. prepared the ST-FMR and MOKE set-ups. J.W. and G.E. performed the Raman measurements. Q.W. contributed the materials. S.S. and S.L. analysed the data with the help of Y.W., P.H. and J.Y. S.S., Z.Z., S.D.P. and H.Y. prepared the manuscript. H.Y. supervised the project. All the authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Hyunsoo Yang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information: Nature Nanotechnology thanks Can Onur Avci and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Supplementary Information

Supplementary Figs. 1–19, Supplementary Tables S1 and S2 and Supplementary refs. 1–29.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shi, S., Liang, S., Zhu, Z. et al. All-electric magnetization switching and Dzyaloshinskii–Moriya interaction in WTe2/ferromagnet heterostructures. Nat. Nanotechnol. 14, 945–949 (2019). https://doi.org/10.1038/s41565-019-0525-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41565-019-0525-8

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing