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.

  • Article
  • Published:

Evidence of non-collinear spin texture in magnetic moiré superlattices

Abstract

Moiré magnetism is emerging as a platform to design and control exotic magnetic phases in twisted magnetic two-dimensional crystals. Non-collinear spin texture emerging from twisted two-dimensional magnets with collinear spins is one of the most profound consequences of moiré magnetism and forms the basis for realizing non-trivial magnetic orders and excitations. However, no direct experimental observations of non-collinear spins in moiré magnets have been made, despite recent theoretical and experimental efforts. Here, we report evidence of non-collinear spin texture in two-dimensional twisted double bilayer CrI3. We distinguish the non-collinear spins with a gradual spin flop process from the collinear spins with sudden spin flip transitions and identify a net magnetization emerging from the collinear spins. We also demonstrate that both non-collinear spins and net magnetization are present at twist angles from 0.5° to 5° but are most prominent for 1.1°. We resolve a critical temperature of 25 K for the onset of the net magnetization and the softening of the non-collinear spins in the 1.1° samples. This is substantially lower than the Néel temperature of 45 K for natural few layers. Our results provide a platform to explore non-trivial magnetism with non-collinear spins.

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

Access options

Buy this article

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

Fig. 1: Calculations of the magnetic ground states of tDB CrI3.
Fig. 2: SAED and DF-TEM of high-quality moiré superlattice in tDB CrI3.
Fig. 3: Magnetic field dependent MCD data, model fits and spin configurations for 1.1° tDB CrI3.
Fig. 4: Twist angle dependence of MCD data of tDB CrI3.
Fig. 5: Temperature dependence of the MCD and polarized Raman scattering data of 1.1° tDB CrI3.

Similar content being viewed by others

Data availability

Raw data for SAED and DF-TEM data are images shown in the main text and Supplementary Information. Raw data for MCD and Raman results are provided as Source data provided with this paper.

References

  1. Nakatsuji, S., Kiyohara, N. & Higo, T. Large anomalous Hall effect in a non-collinear antiferromagnet at room temperature. Nature 527, 212–215 (2015).

    Article  ADS  Google Scholar 

  2. Kimura, T. Spiral magnets as magnetoelectrics. Annu. Rev. Mater. Res. 37, 387–413 (2007).

    Article  ADS  Google Scholar 

  3. Yokouchi, T. et al. Emergent electromagnetic induction in a helical-spin magnet. Nature 586, 232–236 (2020).

    Article  ADS  Google Scholar 

  4. Fert, A., Reyren, N. & Cros, V. Magnetic skyrmions: advances in physics and potential applications. Nat. Rev. Mater. 2, 17031 (2017).

    Article  ADS  Google Scholar 

  5. Liang, T. et al. Orthogonal magnetization and symmetry breaking in pyrochlore iridate Eu2Ir2O7. Nat. Phys. 13, 599–603 (2017).

    Article  Google Scholar 

  6. Gong, C. & Zhang, X. Two-dimensional magnetic crystals and emergent heterostructure devices. Science 363, eaav4450 (2019).

    Article  Google Scholar 

  7. Burch, K. S., Mandrus, D. & Park, J.-G. Magnetism in two-dimensional van der Waals materials. Nature 563, 47–52 (2018).

    Article  ADS  Google Scholar 

  8. Mak, K. F., Shan, J. & Ralph, D. C. Probing and controlling magnetic states in 2D layered magnetic materials. Nat. Rev. Phys. 1, 646–661 (2019).

    Article  Google Scholar 

  9. Huang, B. et al. Emergent phenomena and proximity effects in two-dimensional magnets and heterostructures. Nat. Mater. 19, 1276–1289 (2020).

    Article  ADS  Google Scholar 

  10. Gibertini, M., Koperski, M., Morpurgo, A. F. & Novoselov, K. S. Magnetic 2D materials and heterostructures. Nat. Nanotechnol. 14, 408–419 (2019).

    Article  ADS  Google Scholar 

  11. Wang, Q. H. et al. The magnetic genome of two-dimensional van der Waals materials. ACS Nano 16, 6960–7079 (2022).

    Article  Google Scholar 

  12. Andrei, E. Y. et al. The marvels of moiré materials. Nat. Rev. Mater. 6, 201–206 (2021).

    Article  ADS  Google Scholar 

  13. Kennes, D. M. et al. Moiré heterostructures as a condensed-matter quantum simulator. Nat. Phys. 17, 155–163 (2021).

    Article  Google Scholar 

  14. Hejazi, K., Luo, Z.-X. & Balents, L. Noncollinear phases in moiré magnets. Proc. Natl Acad. Sci. USA 117, 10721–10726 (2020).

    Article  MathSciNet  MATH  ADS  Google Scholar 

  15. Hejazi, K., Luo, Z.-X. & Balents, L. Heterobilayer moiré magnets: moiré skyrmions and commensurate–incommensurate transitions. Phys. Rev. B 104, L100406 (2021).

    Article  ADS  Google Scholar 

  16. Tong, Q., Liu, F., Xiao, J. & Yao, W. Skyrmions in the moiré of van der Waals 2D magnets. Nano Lett. 18, 7194–7199 (2018).

    Article  ADS  Google Scholar 

  17. Akram, M. & Erten, O. Skyrmions in twisted van der Waals magnets. Phys. Rev. B 103, L140406 (2021).

    Article  ADS  Google Scholar 

  18. Akram, M. et al. Moiré skyrmions and chiral magnetic phases in twisted CrX3 (X = I, Br, and Cl) bilayers. Nano Lett. 21, 6633–6639 (2021).

    Article  ADS  Google Scholar 

  19. Xie, H. et al. Twist engineering of the two-dimensional magnetism in double bilayer chromium triiodide homostructures. Nat. Phys. 18, 30–36 (2022).

    Article  Google Scholar 

  20. Xu, Y. et al. Coexisting ferromagnetic–antiferromagnetic state in twisted bilayer CrI3. Nat. Nanotechnol. 17, 143–147 (2022).

    Article  ADS  Google Scholar 

  21. Song, T. et al. Direct visualization of magnetic domains and moiré magnetism in twisted 2D magnets. Science 374, 1140–1144 (2021).

    Article  ADS  Google Scholar 

  22. Chen, L. et al. Magnetic anisotropy in ferromagnetic CrI3. Phys. Rev. B 101, 134418 (2020).

    Article  ADS  Google Scholar 

  23. Huang, B. et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit. Nature 546, 270–273 (2017).

    Article  ADS  Google Scholar 

  24. Li, S. et al. Magnetic-field-induced quantum phase transitions in a van der Waals magnet. Phys. Rev. 10, 011075 (2020).

    Article  Google Scholar 

  25. Li, T. et al. Pressure-controlled interlayer magnetism in atomically thin CrI3. Nat. Mater. 18, 1303–1308 (2019).

    Article  ADS  Google Scholar 

  26. Song, T. et al. Switching 2D magnetic states via pressure tuning of layer stacking. Nat. Mater. 18, 1298–1302 (2019).

    Article  ADS  Google Scholar 

  27. Sivadas, N., Okamoto, S., Xu, X., Fennie, C. J. & Xiao, D. Stacking-dependent magnetism in bilayer CrI3. Nano Lett. 18, 7658–7664 (2018).

    Article  ADS  Google Scholar 

  28. Wang, C., Gao, Y., Lv, H., Xu, X. & Xiao, D. Stacking domain wall magnons in twisted van der Waals magnets. Phys. Rev. Lett. 125, 247201 (2020).

    Article  ADS  Google Scholar 

  29. Jiang, P. et al. Stacking tunable interlayer magnetism in bilayer CrI3. Phys. Rev. B 99, 144401 (2019).

    Article  ADS  Google Scholar 

  30. Sung, S. H. et al. Torsional periodic lattice distortions and diffraction of twisted 2D materials. Nat. Commun. 13, 7826 (2022).

    Article  ADS  Google Scholar 

  31. Jin, W. et al. Tunable layered-magnetism–assisted magneto-Raman effect in a two-dimensional magnet CrI3. Proc. Natl Acad. Sci. USA 117, 24664–24669 (2020).

    Article  ADS  Google Scholar 

  32. Song, T. et al. Giant tunneling magnetoresistance in spin-filter van der Waals heterostructures. Science 360, 1214–1218 (2018).

    Article  ADS  Google Scholar 

  33. Marchiori, E. et al. Nanoscale magnetic field imaging for 2D materials. Nat. Rev. Phys. 4, 49–60 (2022).

    Article  Google Scholar 

  34. Zhang, X.-X. et al. Gate-tunable spin waves in antiferromagnetic atomic bilayers. Nat. Mater. 19, 838–842 (2020).

    Article  ADS  Google Scholar 

  35. Cenker, J. et al. Direct observation of two-dimensional magnons in atomically thin CrI3. Nat. Phys. 17, 20–25 (2021).

    Article  Google Scholar 

  36. Ghosh, A. et al. Intra-atomic and local exchange fields in the van der Waals magnet CrI3. Preprint at arXiv https://doi.org/10.48550/arXiv.2201.04400 (2022).

  37. Jin, W. et al. Raman fingerprint of two terahertz spin wave branches in a two-dimensional honeycomb Ising ferromagnet. Nat. Commun. 9, 5122 (2018).

    Article  ADS  Google Scholar 

  38. Kim, H. H. et al. Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides. Proc. Natl Acad. Sci. USA 116, 11131–11136 (2019).

    Article  ADS  Google Scholar 

  39. Bistritzer, R. & MacDonald, A. H. Moiré bands in twisted double-layer graphene. Proc. Natl Acad. Sci. USA 108, 12233–12237 (2011).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank N. Agarwal for helpful discussions and assistance in SAED and DF-TEM measurements. L.Z. acknowledges support from NSF career grant no. DMR-174774, AFOSR YIP grant no. FA9550-21-1-0065 and the Alfred P. Sloan Foundation. R. He acknowledges support from NSF grant no. DMR-2104036 and NSF career grant no. DMR-1760668. R. Hovden acknowledges support from ARO grant no. W911NF-22-1-0056. S.H.S. acknowledges support from the W.M. Keck Foundation. K.S. acknowledges support from NSF grant no. NSF-EFMA-1741618. H.L. acknowledges support from the National Key R&D Program of China (grant nos. 2018YFE0202600 and 2016YFA0300504), the Beijing Natural Science Foundation (grant no. Z200005) and the Fundamental Research Funds for the Central Universities and Research Funds of Renmin University of China (grant nos. 18XNLG14, 19XNLG17 and 20XNH062).

Author information

Authors and Affiliations

Authors

Contributions

L.Z., H.X. and X.L. conceived the idea and initiated this project. H.X. and Z.S. fabricated the 4L, 2L and tDB CrI3 samples. H.X., X.L., Z.Y., G.Y. and H.G. built the MCD setup and carried out the MCD measurements under the supervision of L.Z. and R. He. S.H.S. and R. Hovden performed the electron diffraction and TEM measurements. S.Y., Y.F., S.T. and H.L. grew the CrI3 bulk single crystals. X.L. and K.S. performed the theoretical computation and analysis. X.L. and L.Z. analysed the data, and X.L., R. He and L.Z. wrote the manuscript. All authors participated in the discussion of the results.

Corresponding authors

Correspondence to Rui He or Liuyan Zhao.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Physics thanks Bevin Huang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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 Sections 1–5.

Source data

Source Data Fig. 3

Raw data for MCD spectra and their fits.

Source Data Fig. 4

Raw data for MCD spectra and their fitted key parameters.

Source Data Fig. 5

Raw data for MCD and Raman spectra and their fits.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xie, H., Luo, X., Ye, Z. et al. Evidence of non-collinear spin texture in magnetic moiré superlattices. Nat. Phys. 19, 1150–1155 (2023). https://doi.org/10.1038/s41567-023-02061-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41567-023-02061-z

This article is cited by

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