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Winding feature and thermal evolution of the gapped Dirac magnons in CrI3

Weiliang Yao1,2,*, Matthew B. Stone3, Colin L. Sarkis3, Yi Li4, Ruixian Liu4, Xingye Lu4, and Pengcheng Dai1,2,†

  • *Contact author: weiliangyao@outlook.com
  • †Contact author: pdai@rice.edu
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Phys. Rev. B 114, 134413 – Published 10 September, 2026

DOI: https://doi.org/10.1103/1rmh-8msr

Abstract

Two-dimensional honeycomb lattice ferromagnet chromium tri-iodide (CrI3) has attracted tremendous interest because it retains ferromagnetism down to the monolayer limit and hosts intriguing topological magnons. As a prototypical van der Waals magnet, CrI3 provides an ideal platform for exploring the interplay between reduced dimensionality, magnetic order, and nontrivial spin excitations. Here, using inelastic neutron scattering together with improved sample quality, we uncover the magnon winding feature around the K-point of the hexagonal Brillouin zone, a key signature of Dirac magnons. In addition, we find that the magnon energy follows a T2-renormalization behavior at elevated temperatures, consistent with magnon-magnon interactions. These results provide previously missing information on the magnon spectrum of CrI3 and further consolidate the topological nature of its spin excitations.

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References (35)

  1. K. S. Burch, D. Mandrus, and J.-G. Park, Magnetism in two-dimensional van der Waals materials, Nature (London) 563, 47 (2018).
  2. M. Gibertini, M. Koperski, A. F. Morpurgo, and K. S. Novoselov, Magnetic 2D materials and heterostructures, Nat. Nanotechnol. 14, 408 (2019).
  3. Q. H. Wang, A. Bedoya-Pinto, M. Blei, A. H. Dismukes, A. Hamo, S. Jenkins, M. Koperski, Y. Liu, Q.-C. Sun, E. J. Telford, H. H. Kim, M. Augustin, U. Vool, J.-X. Yin, L. H. Li, A. Falin, C. R. Dean, F. Casanova, R. F. L. Evans, M. Chshiev, et al., The magnetic genome of two-dimensional van der Waals materials, ACS Nano 16, 6960 (2022).
  4. J.-G. Park, K.-X. Zhang, H. Cheong, J. H. Kim, C. A. Belvin, D. Hsieh, H. Ning, and N. Gedik, 2D van der Waals magnets: From fundamental physics to applications, Rev. Mod. Phys. 98, 025003 (2026).
  5. B. Huang, G. Clark, E. Navarro-Moratalla, D. R. Klein, R. Cheng, K. L. Seyler, D. Zhong, E. Schmidgall, M. A. McGuire, D. H. Cobden, et al., Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit, Nature (London) 546, 270 (2017).
  6. M. A. McGuire, H. Dixit, V. R. Cooper, and B. C. Sales, Coupling of crystal structure and magnetism in the layered, ferromagnetic insulator CrI3, Chem. Mater. 27, 612 (2015).
  7. J. L. Lado and J. Fernández-Rossier, On the origin of magnetic anisotropy in two dimensional CrI3, 2D Mater. 4, 035002 (2017).
  8. S. A. Owerre, A first theoretical realization of honeycomb topological magnon insulator, J. Phys.: Condens. Matter 28, 386001 (2016).
  9. S. S. Pershoguba, S. Banerjee, J. C. Lashley, J. Park, H. Ågren, G. Aeppli, and A. V. Balatsky, Dirac magnons in honeycomb ferromagnets, Phys. Rev. X 8, 011010 (2018).
  10. A. Mook, K. Plekhanov, J. Klinovaja, and D. Loss, Interaction-stabilized topological magnon insulator in ferromagnets, Phys. Rev. X 11, 021061 (2021).
  11. P. A. McClarty, Topological magnons: A review, Annu. Rev. Condens. Matter Phys. 13, 171 (2022).
  12. J. Fransson, A. M. Black-Schaffer, and A. V. Balatsky, Magnon Dirac materials, Phys. Rev. B 94, 075401 (2016).
  13. A. H. Castro Neto, F. Guinea, N. M. R. Peres, K. S. Novoselov, and A. K. Geim, The electronic properties of graphene, Rev. Mod. Phys. 81, 109 (2009).
  14. S. Shivam, R. Coldea, R. Moessner, and P. McClarty, Neutron scattering signatures of magnon Weyl points, arXiv:1712.08535.
  15. L. Chen, J.-H. Chung, B. Gao, T. Chen, M. B. Stone, A. I. Kolesnikov, Q. Huang, and P. Dai, Topological spin excitations in honeycomb ferromagnet CrI3, Phys. Rev. X 8, 041028 (2018).
  16. L. Chen, J.-H. Chung, T. Chen, C. Duan, A. Schneidewind, I. Radelytskyi, D. J. Voneshen, R. A. Ewings, M. B. Stone, A. I. Kolesnikov, B. Winn, S. Chi, R. A. Mole, D. H. Yu, B. Gao, and P. Dai, Magnetic anisotropy in ferromagnetic CrI3, Phys. Rev. B 101, 134418 (2020).
  17. L. Chen, J.-H. Chung, M. B. Stone, A. I. Kolesnikov, B. Winn, V. O. Garlea, D. L. Abernathy, B. Gao, M. Augustin, E. J. G. Santos, and P. Dai, Magnetic field effect on topological spin excitations in CrI3, Phys. Rev. X 11, 031047 (2021).
  18. J. A. Schneeloch, L. Daemen, and D. Louca, Antiferromagnetic-ferromagnetic homostructures with Dirac magnons in the van der Waals magnet CrI3, Phys. Rev. B 109, 024409 (2024).
  19. J. A. Schneeloch, A. A. Aczel, F. Ye, and D. Louca, Role of stacking defects on the magnetic behavior of CrI3, Phys. Rev. B 110, 144439 (2024).
  20. S. Banerjee and S. Humeniuk, Interacting Dirac magnons in the van der Waals ferromagnet CrBr3, Phys. Rev. B 112, 094407 (2025).
  21. R. Eto, I. Salgado-Linares, M. Mochizuki, J. Knolle, and A. Mook, Fate of topological Dirac magnons in van der Waals ferromagnets at finite temperature, Phys. Rev. X 16, 021053 (2026).
  22. Y.-S. Lu, J.-L. Li, and C.-T. Wu, Topological phase transitions of Dirac magnons in honeycomb ferromagnets, Phys. Rev. Lett. 127, 217202 (2021).
  23. G. Granroth, D. Vandergriff, and S. Nagler, SEQUOIA: A fine resolution chopper spectrometer at the SNS, Physica B 385-386, 1104 (2006).
  24. G. E. Granroth, A. I. Kolesnikov, T. E. Sherline, J. P. Clancy, K. A. Ross, J. P. C. Ruff, B. D. Gaulin, and S. E. Nagler, SEQUOIA: A newly operating chopper spectrometer at the SNS, J. Phys.: Conf. Ser. 251, 012058 (2010).
  25. R. Liu, M. B. Stone, S. Gao, M. Nakamura, K. Kamazawa, A. Krajewska, H. C. Walker, P. Cheng, R. Yu, Q. Si, P. Dai, and X. Lu, Spin correlations in the nematic quantum disordered state of FeSe, Nat. Commun. 16, 5212 (2025).
  26. Y. Li, Y. Shangguan, X. Wang, R. Liu, C. Liu, Y. Han, Z. Wang, C. Balz, R. Stewart, S.-L. Yu, J. Wen, J.-X. Li, and X. Lu, Magnetic excitations in biaxial-strain detwinned α−RuCl3, arXiv:2509.06753.
  27. M. B. Stone, G. E. Granroth, D. M. Pajerowski, D. L. Abernathy, D. L. Conner, L. DeBeer-Schmitt, V. R. Fanelli, R. Goyette, A. I. Kolesnikov, R. Mills, et al., Sample changers for direct geometry neutron chopper spectrometers, Sci. Rep. 15, 31936 (2025).
  28. O. Arnold et al., Mantid-Data analysis and visualization package for neutron scattering and μSR experiments, Nucl. Instrum. Methods Phys. Res. Sect. A 764, 156 (2014).
  29. R. Ewings, A. Buts, M. Le, J. van Duijn, I. Bustinduy, and T. Perring, Horace: Software for the analysis of data from single crystal spectroscopy experiments at time-of-flight neutron instruments, Nucl. Instrum. Methods Phys. Res. Sect. A 834, 132 (2016).
  30. Z. Cai, S. Bao, Z.-L. Gu, Y.-P. Gao, Z. Ma, Y. Shangguan, W. Si, Z.-Y. Dong, W. Wang, Y. Wu, D. Lin, J. Wang, K. Ran, S. Li, D. Adroja, X. Xi, S.-L. Yu, X. Wu, J.-X. Li, and J. Wen, Topological magnon insulator spin excitations in the two-dimensional ferromagnet CrBr3, Phys. Rev. B 104, L020402 (2021).
  31. S. E. Nikitin, B. Fåk, K. W. Krämer, T. Fennell, B. Normand, A. M. Läuchli, and C. Rüegg, Thermal evolution of Dirac magnons in the honeycomb ferromagnet CrBr3, Phys. Rev. Lett. 129, 127201 (2022).
  32. S.-H. Do, J. A. M. Paddison, G. Sala, T. J. Williams, K. Kaneko, K. Kuwahara, A. F. May, J. Yan, M. A. McGuire, M. B. Stone, M. D. Lumsden, and A. D. Christianson, Gaps in topological magnon spectra: Intrinsic versus extrinsic effects, Phys. Rev. B 106, L060408 (2022).
  33. M. Elliot, P. A. McClarty, D. Prabhakaran, R. Johnson, H. Walker, P. Manuel, and R. Coldea, Order-by-disorder from bond-dependent exchange and intensity signature of nodal quasiparticles in a honeycomb cobaltate, Nat. Commun. 12, 3936 (2021).
  34. A. Scheie, P. Laurell, P. A. McClarty, G. E. Granroth, M. B. Stone, R. Moessner, and S. E. Nagler, Dirac magnons, nodal lines, and nodal plane in elemental gadolinium, Phys. Rev. Lett. 128, 097201 (2022).
  35. A. Scheie, P. Laurell, P. A. McClarty, G. E. Granroth, M. B. Stone, R. Moessner, and S. E. Nagler, Spin-exchange Hamiltonian and topological degeneracies in elemental gadolinium, Phys. Rev. B 105, 104402 (2022).

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Phys. Rev. B 114, 134413– Published 10 September, 2026
  • Received 6 May 2026
  • Accepted 26 August 2026
Article part of CHORUS
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