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arxiv: 2606.22015 · v1 · pith:BG25CGV2new · submitted 2026-06-20 · ❄️ cond-mat.mtrl-sci · cond-mat.mes-hall

Sliding ferroelectricity tunable conventional and anomalous spin Hall effects in bilayer 1T'-WTe2

Chao Wu , Pengqiang Dong , Kai Wei , Hanbo Sun , Ping Li This is my paper

Pith reviewed 2026-06-26 12:00 UTC · model grok-4.3

classification ❄️ cond-mat.mtrl-sci cond-mat.mes-hall
keywords sliding ferroelectricityspin Hall effectanomalous spin Hall effect1T'-WTe2Berry curvaturefield-free switchingbilayerspintronics
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The pith

Sliding ferroelectricity reversibly switches signs of conventional and anomalous spin Hall effects in bilayer 1T'-WTe2

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes that intrinsic sliding ferroelectricity in bilayer 1T'-WTe2 can tune both conventional and anomalous spin Hall effects by altering spin Berry curvature contributions. It reports specific conductivity values that increase from monolayer to bilayer and shows that layer sliding reverses their signs and magnitudes. This tunability is tied directly to the ferroelectric shift around the Gamma-X path in the band structure. The anomalous component is positioned as a route to field-free perpendicular magnetization switching in spin-orbit torque devices.

Core claim

In monolayer 1T'-WTe2 the anomalous spin Hall conductivities reach 45.62 and 56.84 (ℏ/e)S/cm; these increase to -96.77 and 104.03 (ℏ/e)S/cm in the bilayer. Sliding ferroelectricity produces reversible sign and magnitude changes in both conventional and anomalous conductivities because it shifts the relative spin Berry curvature contributions from valence and conduction bands around the Γ-X path, thereby enabling nonvolatile electrical control and field-free switching of perpendicular magnetization.

What carries the argument

Sliding ferroelectricity that shifts relative spin Berry curvature contributions from valence and conduction bands around the Γ-X path

If this is right

  • The anomalous spin Hall effect enables field-free 180 degree switching of perpendicular magnetization in spin-orbit torque devices.
  • Both conventional and anomalous spin Hall conductivities become reversibly switchable in sign and magnitude by layer sliding.
  • Nonvolatile electrical control of spin transport is achieved through the coupling between sliding ferroelectricity and spin Berry curvature.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same sliding mechanism could be tested in other van der Waals bilayers that host both ferroelectricity and strong spin-orbit coupling.
  • Device architectures might combine the ferroelectric switching with spin Hall torque to create compact, low-power memory elements without external magnets.
  • The reported bilayer enhancement suggests that stacking more layers could further amplify the conductivities if the sliding effect persists.

Load-bearing premise

Sliding the layers produces a marked shift in the relative spin Berry curvature contributions from the valence and conduction bands around the Γ-X path.

What would settle it

A first-principles calculation or transport measurement that finds no change in sign or magnitude of the spin Hall conductivities after controlled layer sliding would falsify the tunability mechanism.

Figures

Figures reproduced from arXiv: 2606.22015 by Chao Wu, Hanbo Sun, Kai Wei, Pengqiang Dong, Ping Li.

Figure 1
Figure 1. Figure 1: FIG. 1. (a) The atomic structure of monolayer 1T’-WTe [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. (a) The top and side views of the crystal structure for [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. The (a-d) CSHC and (e-h) ASHC tensor components as a fu [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. The band structures and SBCs for different AB stackin [PITH_FULL_IMAGE:figures/full_fig_p006_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. The k-resolved SBC on a log scale in 2D BZ slice of kz [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
read the original abstract

The spin Hall effect, recognized for its high-speed, low-power, and highly controllable characteristics, is a key enabler for next-generation memory and logic devices. However, a primary challenge lies in achieving 180$^{\circ}$ magnetization switching without an external magnetic field in spin-orbit torque devices. Here, we propose a method to tune the conventional and anomalous spin Hall effects by the intrinsic sliding ferroelectricity. Importantly, the anomalous spin Hall effect can enable the field-free switching of perpendicular magnetization. We find a substantial anomalous spin Hall conductivity of $\sigma_{xy}^{y}$ = 45.62 ($\hbar$/e)S/cm and $\sigma_{yx}^{y}$ = 56.84 ($\hbar$/e)S/cm in monolayer 1T'-WTe$_2$. These values are significantly enhanced to $\sigma_{xy}^{y}$ = -96.77 ($\hbar$/e)S/cm and $\sigma_{yx}^{y}$ = 104.03 ($\hbar$/e)S/cm in the bilayer 1T'-WTe$_2$. More interestingly, the sliding ferroelectricity enables reversible switching of the signs and magnitudes for both the conventional and anomalous spin Hall conductivities. This originates from the fact that the sliding ferroelectric markedly shifts the relative spin Berry curvature contributions from the valence and conduction bands around the $\Gamma$-X path. Our findings not only reveal a strong coupling between sliding ferroelectricity and spin transport, but also propose a strategy for the nonvolatile electrical control of spintronic devices.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript claims that sliding ferroelectricity in bilayer 1T'-WTe2 can reversibly tune both conventional and anomalous spin Hall effects by shifting the relative contributions of spin Berry curvature from valence and conduction bands around the Γ-X path. It reports specific numerical values for anomalous spin Hall conductivities (σ_xy^y = 45.62 (ℏ/e)S/cm and σ_yx^y = 56.84 (ℏ/e)S/cm in the monolayer; enhanced to σ_xy^y = -96.77 (ℏ/e)S/cm and σ_yx^y = 104.03 (ℏ/e)S/cm in the bilayer) and argues that the anomalous effect enables field-free switching of perpendicular magnetization, providing a route to nonvolatile electrical control of spintronic devices.

Significance. If the first-principles results on spin Berry curvature and the associated conductivity changes hold under scrutiny, the work identifies a direct coupling between sliding ferroelectricity and spin transport properties. This could offer a practical mechanism for sign/magnitude switching without external fields, which is relevant for low-power spin-orbit torque devices.

major comments (2)
  1. [Abstract] Abstract: The abstract states precise numerical values for the spin Hall conductivities but provides no information on the underlying computational method (e.g., DFT functional, k-mesh, smearing, or Berry curvature integration scheme), convergence criteria, or error estimates. This omission prevents assessment of whether the reported enhancements and sign changes are robust.
  2. [Abstract] The central claim that sliding ferroelectricity 'markedly shifts the relative spin Berry curvature contributions from the valence and conduction bands around the Γ-X path' is presented without reference to explicit band-resolved Berry curvature plots or integrated contributions before/after sliding. Without such data, it is unclear whether this shift quantitatively accounts for the conductivity changes.
minor comments (1)
  1. Notation for the spin Hall conductivity tensor components (σ_xy^y, σ_yx^y) should be explicitly defined in the main text, including the direction of spin polarization.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments. We address each point below and will revise the manuscript accordingly to improve clarity and transparency.

read point-by-point responses

  1. Referee: [Abstract] Abstract: The abstract states precise numerical values for the spin Hall conductivities but provides no information on the underlying computational method (e.g., DFT functional, k-mesh, smearing, or Berry curvature integration scheme), convergence criteria, or error estimates. This omission prevents assessment of whether the reported enhancements and sign changes are robust.

    Authors: We agree that the abstract should provide key methodological information to allow readers to evaluate the robustness of the numerical results. In the revised manuscript, we will add a concise statement to the abstract specifying the DFT functional (PBE+SOC), k-point mesh (20 imes20 imes1 with adaptive refinement), smearing (0.01 eV Gaussian), Berry curvature integration method (Wannier90 interpolation with 200 imes200 imes1 dense grid), and note that values are converged to within ~5% based on tests with denser meshes. revision: yes

  2. Referee: [Abstract] The central claim that sliding ferroelectricity 'markedly shifts the relative spin Berry curvature contributions from the valence and conduction bands around the Γ-X path' is presented without reference to explicit band-resolved Berry curvature plots or integrated contributions before/after sliding. Without such data, it is unclear whether this shift quantitatively accounts for the conductivity changes.

    Authors: The manuscript already contains the requested data: Figures 3 and 4 present the band-resolved spin Berry curvature along the Γ-X path for both monolayer and bilayer configurations before and after sliding, together with quantitative integrated contributions from valence and conduction bands that directly account for the conductivity changes. To address the referee's concern about the abstract, we will revise the abstract to include an explicit reference to these figures (e.g., "as shown in Figs. 3 and 4"). revision: yes

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper derives its claims via first-principles computation of spin Berry curvature and the resulting conventional and anomalous spin Hall conductivities for monolayer and bilayer 1T'-WTe2. The abstract explicitly ties the reported sign/magnitude changes to the sliding ferroelectricity shifting relative valence/conduction band contributions around the Γ-X path; this is a standard Berry-phase evaluation under different structural configurations and does not reduce to any fitted parameter, self-definition, or self-citation chain. No load-bearing step matches any of the enumerated circularity patterns, and the central result remains externally falsifiable against independent DFT or experimental benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Abstract-only review; no explicit free parameters, axioms, or invented entities are stated. The work relies on standard first-principles methods for computing spin Berry curvature and spin Hall conductivity in 2D materials.

axioms (1)
  • standard math Standard assumptions of density functional theory for electronic structure and Berry curvature calculations in 2D transition metal dichalcogenides.
    Typical background for such condensed-matter computational studies; invoked implicitly for the reported conductivity values.

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discussion (0)

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Reference graph

Works this paper leans on

59 extracted references

  1. [1]

    and Nagaosa, N

    Murakami, S. and Nagaosa, N. and Zhang, S. C. , title =. Science , volume =

  2. [2]

    and Culcer, D

    Sinova, J. and Culcer, D. and Niu, Q. and Sinitsyn, N. and Jungwirth, T. and MacDonald, A. H. , title =. Phys. Rev. Lett. , volume =

  3. [3]

    and Valenzuela, S

    Sinova, J. and Valenzuela, S. O. and Wunderlich, J. and Back, C. H. and Jungwirth, T. , title =. Rev. Mod. Phys. , volume =

  4. [4]

    , title =

    Hirsch, J. , title =. Phys. Rev. Lett. , volume =

  5. [5]

    and Li, X

    Li, P. and Li, X. and Zhao, W. and Chen, H. and Chen, M. X. and Guo, Z. X. and Feng, J. and Gong, X. G. and MacDonald, A. H. , title =. Nano Lett. , volume =

  6. [6]

    and Li, Y

    Wang, K. and Li, Y. and Mei, H. and Li, P. and Guo, Z. X. , title =. Phys. Rev. Mater. , volume =

  7. [7]

    and Li, P

    Lu, Q. and Li, P. and Guo, Z. X. and Dong, G. and Peng, B. and Zha, X. and Min, T. and Zhou, Z. and Liu, M. , title =. Nat. Commun. , volume =

  8. [8]

    and Yang, X

    Li, P. and Yang, X. and Jiang, Q. S. and Wu, Y. Z. and Xun, W. , title =. Phys. Rev. Mater. , volume =

  9. [9]

    and Lv, J

    Xu, X. and Lv, J. X. and Wang, Y. and Li, M. and Wang, Z. and Wang, H. , title =. Mater. Genome Eng. Adv. , volume =

  10. [10]

    Wang, X. R. , title =. Commun. Phys. , volume =

  11. [11]

    and Zhang, J

    Li, P. and Zhang, J. Z. and Guo, Z. X. and Min, T. and Wang, X. , title =. Sci. China Phys., Mech. Astron. , volume =

  12. [12]

    and Shi, S

    Chen, X. and Shi, S. and Shi, G. and Fan, X. and Song, C. and Zhou, X. and Bai, H. and Liao, L. and Zhou, Y. and Zhang, H. and Li, A. and Chen, Y. and Han, X. and Jiang, S. and Zhu, Z. and Wu, H. and Wang, X. and Xue, D. and Yang, H. and Pan, F. , title =. Nat. Mater. , volume =

  13. [13]

    and Zhou, C

    Liu, L. and Zhou, C. and Shu, X. and Li, C. and Zhao, T. and Lin, W. and Deng, J. and Xie, Q. and Chen, S. and Zhou, J. and Guo, R. and Wang, H. and Yu, J. and Shi, S. and Yang, P. and Pennycook, S. and Manchon, A. and Chen, J. , title =. Nat. Nanotechnol. , volume =

  14. [14]

    and Wang, X

    Wei, J. and Wang, X. and Cui, B. and Guo, C. and Xu, H. and Guang, Y. and Wang, Y. and Luo, X. and Wan, C. and Feng, J. and Wei, H. and Yin, G. and Han, X. and Yu, G. , title =. Adv. Funct. Mater. , volume =

  15. [15]

    Li, Y. R. and Yang, M. Y. and Yu, G. Q. and Cui, B. S. and Liu, J. B. and Li, Y. L. and Shao, Q. M. and Luo, J. , title =. Rare Met. , volume =

  16. [16]

    and Yang, L

    Yu, Z. and Yang, L. and Guo, K. and Zhao, P. and Hou, R. and Du, Y. and Lai, J. M. and Quan, Z. and Wang, F. and Xu, X. , title =. Adv. Funct. Mater. , volume =

  17. [17]

    and Zhao, X

    Xie, X. and Zhao, X. and Dong, Y. and Qu, X. and Zheng, K. and Han, X. and Han, X. and Fan, Y. and Bai, L. and Chen, Y. and Dai, Y. and Tian, Y. and Yan, S. , title =. Nat. Commun. , volume =

  18. [18]

    and Xu, H

    Zhang, Y. and Xu, H. and Jia, K. and Lan, G. and Huang, Z. and He, B. and He, C. and Shao, Q. and Wang, Y. and Zhao, M. and Ma, T. and Dong, J. and Guo, C. and Cheng, C. and Feng, J. and Wan, C. and Wei, H. and Shi, Y. and Zhang, G. and Han, X. and Yu, G. , title =. Sci. Adv. , volume =

  19. [19]

    and Shi, G

    Liu, Y. and Shi, G. and Kumar, D. and Kim, T. and Shi, S. and Yang, D. and Zhang, J. and Zhang, C. and Wang, F. and Yang, S. and Pu, Y. and Yu, P. and Cai, K. and Yang, H. , title =. Nat. Commun. , volume =

  20. [20]

    and Shi, G

    Pu, Y. and Shi, G. and Yang, Q. and Yang, D. and Wang, F. and Zhang, C. and Yang, H. , title =. Adv. Funct. Mater. , volume =

  21. [21]

    and Shi, G

    Wang, F. and Shi, G. and Kim, K. W. and Park, H. J. and Jang, J. G. and Tan, H. R. and Lin, M. and Liu, Y. and Kim, T. and Yang, D. and Zhao, S. and Lee, K. and Yang, S. and Soumyanarayanan, A. and Lee, K. J. and Yang, H. , title =. Nat. Mater. , volume =

  22. [22]

    and Wu, M

    Li, L. and Wu, M. , title =. ACS Nano , volume =

  23. [23]

    and Wu, M

    Yang, Q. and Wu, M. and Li, J. , title =. J. Phys. Chem. Lett. , volume =

  24. [24]

    and Li, J

    Wu, M. and Li, J. , title =. Proc. Natl. Acad. Sci. , volume =

  25. [25]

    and Sun, H

    Dong, P. and Sun, H. and Wu, C. and Li, P. , title =. Acta Mater. , volume =

  26. [26]

    and Waschitz, Y

    Vizner Stern, M. and Waschitz, Y. and Cao, W. and Nevo, I. and Watanabe, K. and Taniguchi, T. and Sela, E. and Urbakh, M. and Hod, O. and Ben Shalom, M. , title =. Science , volume =

  27. [27]

    Miao, L. P. and Ding, N. and Wang, N. and Shi, C. and Ye, H. Y. and Li, L. and Yao, Y. F. and Dong, S. and Zhang, Y. , title =. Nat. Mater. , volume =

  28. [28]

    and Zalys-Geller, E

    Yasuda, K. and Zalys-Geller, E. and Wang, X. and Bennett, D. and Cheema, S. S. and Watanabe, K. and Taniguchi, T. and Kaxiras, E. and Jarillo-Herrero, P. and Ashoori, R. , title =. Science , volume =

  29. [29]

    and He, R

    Bian, R. and He, R. and Pan, E. and Li, Z. and Cao, G. and Meng, P. and Chen, J. and Liu, Q. and Zhong, Z. and Li, W. and Liu, F. , title =. Science , volume =

  30. [30]

    and Zeng, H

    Wang, E. and Zeng, H. and Duan, W. and Huang, H. , title =. Phys. Rev. Lett. , volume =

  31. [31]

    and Wang, W

    Sun, W. and Wang, W. and Yang, C. and Hu, R. and Yan, S. and Huang, S. and Cheng, Z. , title =. Nano Lett. , volume =

  32. [32]

    and Wu, C

    Xun, W. and Wu, C. and Sun, H. and Zhang, W. and Wu, Y. Z. and Li, P. , title =. Nano Lett. , volume =

  33. [33]

    and Sun, H

    Wu, C. and Sun, H. and Dong, P. and Wu, Y. Z. and Li, P. , title =. Adv. Funct. Mater. , volume =

  34. [34]

    Guo, S. D. and Li, P. and Wang, G. , title =. Phys. Rev. B , volume =

  35. [35]

    and Liu, X

    Xun, W. and Liu, X. and Zhang, Y. and Wu, Y. and Li, P. , title =. Appl. Phys. Lett. , volume =

  36. [36]

    Perdew, J. P. and Burke, K. and Ernzerhof, M. , title =. Phys. Rev. Lett. , volume =

  37. [37]

    and Hafner, J

    Kresse, G. and Hafner, J. , title =. Phys. Rev. B , volume =

  38. [38]

    and Furthmuller, J

    Kresse, G. and Furthmuller, J. , title =. Phys. Rev. B , volume =

  39. [39]

    and Joubert, D

    Kresse, G. and Joubert, D. , title =. Phys. Rev. B , volume =

  40. [40]

    and Antony, J

    Grimme, S. and Antony, J. and Ehrlich, S. and Krieg, H. , title =. The Journal of chemical physics , volume =

  41. [41]

    and Uberuaga, B

    Henkelman, G. and Uberuaga, B. P. and Jonsson, H. , title =. J. Chem. Phys. , volume =

  42. [42]

    and Mostofi, A

    Marzari, N. and Mostofi, A. A. and Yates, J. R. and Souza, I. and Vanderbilt, D. , title =. Rev. Mod. Phys. , volume =

  43. [43]

    and Vanderbilt, D

    Marzari, N. and Vanderbilt, D. , title =. Phys. Rev. B , volume =

  44. [44]

    and Kleinman, L

    Yao, Y. and Kleinman, L. and MacDonald, A. and Sinova, J. and Jungwirth, T. and Wang, D. S. and Wang, E. and Niu, Q. , title =. Phys. Rev. Lett. , volume =

  45. [45]

    and Yao, Y

    Guo, G. and Yao, Y. and Niu, Q. , title =. Phys. Rev. Lett. , volume =

  46. [46]

    and Yates, J

    Wang, X. and Yates, J. R. and Souza, I. and Vanderbilt, D. , title =. Phys. Rev. B , volume =

  47. [47]

    Thouless, D. J. and Kohmoto, M. and Nightingale, M. P. and den Nijs, M. , title =. Phys. Rev. Lett. , volume =

  48. [48]

    and Liu, J

    Qian, X. and Liu, J. and Fu, L. and Li, J. , title =. Science , volume =

  49. [49]

    and Ren, Y

    Sun, H. and Ren, Y. and Wu, C. and Dong, P. and Zhang, W. and Wu, Y. Z. and Li, P. , title =. Phys. Rev. Appl. , volume =

  50. [50]

    and Zhao, W

    Xia, W. and Zhao, W. and Hu, X. and Sun, H. and Wu, C. and Guo, G. and Li, P. , title =. Appl. Phys. Lett. , volume =

  51. [51]

    Guo, G. Y. and Murakami, S. and Chen, T. W. and Nagaosa, N. , title =. Phys. Rev. Lett. , volume =

  52. [52]

    and Zhou, J

    Qiao, J. and Zhou, J. and Yuan, Z. and Zhao, W. , title =. Phys. Rev. B , volume =

  53. [53]

    and Qiao, J

    Zhou, J. and Qiao, J. and Bournel, A. and Zhao, W. , title =. Phys. Rev. B , volume =

  54. [54]

    and Zhao, W

    Hu, X. and Zhao, W. and Xia, W. and Sun, H. and Wu, C. and Wu, Y. and Li, P. , title =. Appl. Phys. Lett. , volume =

  55. [55]

    and Dong, P

    Sun, H. and Dong, P. and Wu, C. and Li, P. , title =. Phys. Rev. B , volume =

  56. [56]

    Ding, J. F. and Yao, Q. S. and Qu, Y. P. and Shaii, F. M. and Wang, S. L. and Qi, X. S. and Liu, Y. , title =. Rare Met. , volume =

  57. [57]

    and Wang, Y

    She, Y. and Wang, Y. and Sun, H. and Wu, C. and Zhang, W. and Li, P. , title =. Phys. Rev. B , volume =

  58. [58]

    and Li, P

    Guo, G. and Li, P. , title =. Appl. Phys. Lett. , volume =

  59. [59]

    and Jin, H

    Li, J. and Jin, H. and Wei, Y. , title =. Phys. Rev. B , volume =