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arxiv: 2606.00398 · v1 · pith:ITSFTRTAnew · submitted 2026-05-29 · ❄️ cond-mat.mtrl-sci

Robust control over polar skyrmion bubble density with a combined optical and electrical approach

Lingyuan Gao , Laurent Bellaiche This is my paper

Pith reviewed 2026-06-28 21:30 UTC · model grok-4.3

classification ❄️ cond-mat.mtrl-sci
keywords polar skyrmion bubblesferroelectric ultrathin filmstwisted lightDC electric fieldbubble density controlnucleation ratenon-volatile memoryfirst-principles calculations
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The pith

Twisted light assisted by a DC electric field can tune the density of polar skyrmion bubbles in ferroelectric ultrathin films between 10^2 and 10^4 per square micron.

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

The paper uses first-principles-based calculations to establish that twisted light, with its spatially inhomogeneous field, combined with a uniform DC electric field, can adjust the number of polar skyrmion bubbles per unit area in ferroelectric films over a wide range. This control extends to the speed at which bubbles nucleate and annihilate when field strengths and beam radius are varied together. A sympathetic reader would care because polar skyrmion bubbles are proposed for non-volatile memory, where the stored information density scales directly with bubble count. The calculations indicate that the combined fields produce responses distinct from those of uniform fields alone.

Core claim

When assisted with a DC electric field, twisted light can robustly tune the density of polar skyrmion bubbles in ferroelectric ultrathin films between 10^2 and 10^4 bit per square micron. Modulating the DC and optical field strengths together with the beam radius also allows control over the nucleation rate that governs creation and annihilation speeds. These responses arise from the interaction of the inhomogeneous optical field pattern with the uniform electric field in the film.

What carries the argument

The spatially inhomogeneous electric field of twisted light combined with a uniform DC electric field, acting on the swirling polarization textures of the bubbles.

If this is right

  • Information density in memory devices based on these bubbles can be set directly by the combined fields.
  • Nucleation rates can be adjusted for faster writing and erasing operations.
  • The approach enables ultrahigh-density non-volatile memory technologies in ferroelectric nanofilms.
  • The distinct response to combined optical and electric fields opens control routes not available with electric fields alone.

Where Pith is reading between the lines

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

  • If the calculated densities hold in devices, hybrid optical-electrical writing schemes could be integrated into existing ferroelectric memory architectures.
  • The wide density window suggests the method could bridge current nanoscale bit densities with future ultradense requirements.
  • Similar field combinations might be tested on other topological polarization patterns in related oxide systems.

Load-bearing premise

The first-principles-based calculations accurately capture the real nucleation and stability behavior of polar skyrmion bubbles under the combined inhomogeneous optical and uniform electric fields.

What would settle it

An experiment applying twisted light plus a DC electric field to a real ferroelectric ultrathin film and finding bubble densities that remain outside the 10^2 to 10^4 per square micron window for all tested field strengths and radii would falsify the claim.

Figures

Figures reproduced from arXiv: 2606.00398 by Laurent Bellaiche, Lingyuan Gao.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p017_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p018_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p019_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p020_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p021_5.png] view at source ↗
read the original abstract

Polar skyrmion bubbles are nanoscale ferroelectric domain configurations with swirling polarization textures, and often emerge in ferroelectric oxide systems. Owing to their inhomogeneous polarization patterns, which endow them with distinct topologies and electrical responses from homogeneous monodomains, polar skyrmion bubbles are envisaged to be promising candidates for non-volatile memory devices. In such device, the recorded information density is directly proportional to the density of bubbles, underscoring the need for precise control over bubble nucleation. Here, using first-principles-based calculations, we demonstrate that when assisted with a DC electric field, twisted light, which has a spatially inhomogeneous field pattern, can robustly tune the density of polar skyrmion bubbles in ferroelectric ultrathin films between $10^2\sim 10^4 \rm{bit}/\mu m^2$. Moreover, by modulating DC and optical field strengths together with the beam radius, the nucleation rate, which characterizes the creation and annihilation speed of polar skyrmion bubbles, can also be well controlled. These findings highlight the unique response of ferroelectric nanofilms to optical and electric fields, which is crucial for employing polar skyrmion bubbles in the next-generation of ultrahigh-density memory technologies.

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

3 major / 2 minor

Summary. The manuscript uses first-principles-based calculations to demonstrate that twisted light (with its spatially inhomogeneous electric-field pattern) assisted by a uniform DC electric field can robustly tune the density of polar skyrmion bubbles in ferroelectric ultrathin films over the range 10²–10⁴ bit/μm²; it further claims that simultaneous modulation of DC field, optical intensity, and beam radius controls the nucleation rate.

Significance. If the underlying model is accurate, the work identifies a potentially useful combined optical-electrical protocol for achieving high areal densities and tunable switching speeds in polar-skyrmion-based memory devices. The two-order-of-magnitude density window and the explicit dependence on beam radius are the most distinctive quantitative results.

major comments (3)
  1. [Computational Methods] Computational Methods section: the precise form of the optical perturbation added to the effective Hamiltonian (or to the first-principles-derived energy landscape) is not derived or benchmarked against known limits for inhomogeneous light-matter coupling in ferroelectrics; because the central claim rests on accurate nucleation barriers under a spatially varying field, this omission is load-bearing.
  2. [Results] Results, density-vs-field plots (presumably Figs. 3–5): the reported 10²–10⁴ bit/μm² window is obtained at zero temperature with a perfect lattice; no sensitivity analysis to thermal fluctuations, point defects, or substrate strain is provided, yet these factors directly affect whether the simulated densities remain accessible in real ultrathin films.
  3. [Results] Nucleation-rate analysis: the definition and extraction of the nucleation rate from the simulations are not cross-checked against any experimental time scales or against simpler Landau-Devonshire models; without such anchoring the claim that the rate “can also be well controlled” cannot be evaluated quantitatively.
minor comments (2)
  1. [Abstract] The abstract states the density range with a tilde; the corresponding figures should report the precise numerical bounds and the number of independent runs used to obtain them.
  2. [Throughout] Notation for the optical beam radius and the DC-field direction should be introduced once and used consistently in all equations and figure captions.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive and detailed review. We address each major comment point by point below.

read point-by-point responses

  1. Referee: [Computational Methods] Computational Methods section: the precise form of the optical perturbation added to the effective Hamiltonian (or to the first-principles-derived energy landscape) is not derived or benchmarked against known limits for inhomogeneous light-matter coupling in ferroelectrics; because the central claim rests on accurate nucleation barriers under a spatially varying field, this omission is load-bearing.

    Authors: We agree that the Computational Methods section would benefit from an explicit derivation of the optical perturbation term. In the revised manuscript we will add a dedicated subsection deriving the form of the inhomogeneous electric-field contribution from twisted light that is added to the effective Hamiltonian, together with benchmarks against established limits for light-matter coupling in ferroelectrics. This will directly support the nucleation-barrier calculations. revision: yes

  2. Referee: [Results] Results, density-vs-field plots (presumably Figs. 3–5): the reported 10²–10⁴ bit/μm² window is obtained at zero temperature with a perfect lattice; no sensitivity analysis to thermal fluctuations, point defects, or substrate strain is provided, yet these factors directly affect whether the simulated densities remain accessible in real ultrathin films.

    Authors: The reported densities are obtained at zero temperature on a defect-free lattice, which is the standard setting for first-principles-based effective-Hamiltonian studies that isolate the field-induced effects. We will add a new paragraph in the revised manuscript that discusses the expected influence of thermal fluctuations, point defects, and substrate strain on the accessible density window and that qualifies the 10²–10⁴ bit/μm² range as an ideal-case result. A comprehensive sensitivity analysis lies outside the scope of the present work. revision: partial

  3. Referee: [Results] Nucleation-rate analysis: the definition and extraction of the nucleation rate from the simulations are not cross-checked against any experimental time scales or against simpler Landau-Devonshire models; without such anchoring the claim that the rate “can also be well controlled” cannot be evaluated quantitatively.

    Authors: We will expand the description of how the nucleation rate is defined and extracted from the molecular-dynamics trajectories in the revised manuscript. In addition, we will include a short comparison of the simulated rates with those obtained from a minimal Landau-Devonshire model to provide an independent anchor. Direct quantitative mapping to experimental time scales remains difficult because of the coarse-grained nature of the effective Hamiltonian, but the added comparison will allow readers to assess the claimed controllability more quantitatively. revision: yes

Circularity Check

0 steps flagged

No circularity: first-principles simulation outputs density range directly from field inputs

full rationale

The paper's central result is obtained by running first-principles-based effective-Hamiltonian simulations under superimposed uniform DC and spatially varying optical fields. No parameter is fitted to the reported 10^2–10^4 bit/μm² window, no uniqueness theorem is invoked via self-citation, and no ansatz or renaming reduces the output to the input by construction. The nucleation-rate and density values are therefore independent computational predictions rather than tautological restatements of the model setup.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review supplies no explicit free parameters, axioms, or invented entities; all entries left empty.

pith-pipeline@v0.9.1-grok · 5743 in / 985 out tokens · 19386 ms · 2026-06-28T21:30:20.386351+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

61 extracted references

  1. [1]

    Matter , volume=

    Local manipulation and topological phase transitions of polar skyrmions , author=. Matter , volume=. 2022 , publisher=

    2022

  2. [2]

    Physical Review Letters , volume=

    Dynamics of polar skyrmion bubbles under electric fields , author=. Physical Review Letters , volume=. 2022 , publisher=

    2022

  3. [3]

    Strain manipulation of ferroelectric skyrmion bubbles in a freestanding

    Zhang, Yixuan and Li, Qian and Huang, Houbing and Hong, Jiawang and Wang, Xueyun , journal=. Strain manipulation of ferroelectric skyrmion bubbles in a freestanding. 2022 , publisher=

    2022

  4. [4]

    npj Quantum Materials , volume=

    Dynamic mechanical writing of skyrmion-like polar nanodomains , author=. npj Quantum Materials , volume=. 2025 , publisher=

    2025

  5. [5]

    Nature , volume=

    Observation of room-temperature polar skyrmions , author=. Nature , volume=. 2019 , publisher=

    2019

  6. [6]

    Nature Communications , volume=

    Absence of critical thickness for polar skyrmions with breaking the Kittel’s law , author=. Nature Communications , volume=. 2023 , publisher=

    2023

  7. [7]

    Advanced Materials , volume=

    Nanoscale-confined terahertz polaritons in a van der Waals crystal , author=. Advanced Materials , volume=. 2021 , publisher=

    2021

  8. [8]

    Nature Materials , volume=

    Ultraconfined terahertz phonon polaritons in hafnium dichalcogenides , author=. Nature Materials , volume=. 2025 , publisher=

    2025

  9. [9]

    Physical Review Letters , volume=

    Dynamical control of topology in polar skyrmions via twisted light , author=. Physical Review Letters , volume=. 2024 , publisher=

    2024

  10. [10]

    Nature Communications , volume=

    Motion and teleportation of polar bubbles in low-dimensional ferroelectrics , author=. Nature Communications , volume=. 2024 , publisher=

    2024

  11. [11]

    Reviews of Modern Physics , volume=

    Topological phases in polar oxide nanostructures , author=. Reviews of Modern Physics , volume=. 2023 , publisher=

    2023

  12. [12]

    Advanced Materials , volume=

    Recent progress on topological structures in ferroic thin films and heterostructures , author=. Advanced Materials , volume=. 2021 , publisher=

    2021

  13. [13]

    Nature Materials , volume=

    Spherical ferroelectric solitons , author=. Nature Materials , volume=. 2023 , publisher=

    2023

  14. [14]

    Nature Communications , volume=

    Discovery of stable skyrmionic state in ferroelectric nanocomposites , author=. Nature Communications , volume=. 2015 , publisher=

    2015

  15. [15]

    Advanced Materials , volume=

    Nanoscale bubble domains and topological transitions in ultrathin ferroelectric films , author=. Advanced Materials , volume=. 2017 , publisher=

    2017

  16. [16]

    Creating Ferroelectricity and Ultrahigh-Density Polar Skyrmion in Paraelectric Perovskite Oxide Monolayers by Moir

    Xu, Tao and Qian, Tao and Pang, Jiafei and Zhang, Jingtong and Li, Sheng and He, Ri and Wang, Jie and Shimada, Takahiro , journal=. Creating Ferroelectricity and Ultrahigh-Density Polar Skyrmion in Paraelectric Perovskite Oxide Monolayers by Moir. 2025 , publisher=

    2025

  17. [17]

    Physical Review B , volume=

    Tailoring optical excitation to control magnetic skyrmion nucleation , author=. Physical Review B , volume=. 2022 , publisher=

    2022

  18. [18]

    ACS Applied Materials & Interfaces , volume=

    Precise tuning of skyrmion density in a controllable manner by ion irradiation , author=. ACS Applied Materials & Interfaces , volume=. 2022 , publisher=

    2022

  19. [19]

    Nano Letters , volume=

    The skyrmion switch: turning magnetic skyrmion bubbles on and off with an electric field , author=. Nano Letters , volume=. 2017 , publisher=

    2017

  20. [20]

    Phase transitions in

    Zhong, W and Vanderbilt, David and Rabe, KM , journal=. Phase transitions in. 1994 , publisher=

    1994

  21. [21]

    First-principles theory of ferroelectric phase transitions for perovskites: The case of

    Zhong, W and Vanderbilt, David and Rabe, KM , journal=. First-principles theory of ferroelectric phase transitions for perovskites: The case of. 1995 , publisher=

    1995

  22. [22]

    Physical review A , volume=

    Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes , author=. Physical review A , volume=. 1992 , publisher=

    1992

  23. [23]

    Nature Communications , volume=

    Designing lead-free antiferroelectrics for energy storage , author=. Nature Communications , volume=. 2017 , publisher=

    2017

  24. [24]

    Giant electrocaloric response in the prototypical

    Jiang, Zhijun and Nahas, Y and Prokhorenko, Sergei and Prosandeev, S and Wang, D and. Giant electrocaloric response in the prototypical. Physical Review B , volume=. 2018 , publisher=

    2018

  25. [25]

    Physical Review B , volume=

    Low-dimensional ferroelectrics under different electrical and mechanical boundary conditions: Atomistic simulations , author=. Physical Review B , volume=. 2005 , publisher=

    2005

  26. [26]

    Nature Communications , volume=

    Hopfions emerge in ferroelectrics , author=. Nature Communications , volume=. 2020 , publisher=

    2020

  27. [27]

    Advanced Materials , volume=

    Polarization topology at the nominally charged domain walls in uniaxial ferroelectrics , author=. Advanced Materials , volume=. 2022 , publisher=

    2022

  28. [28]

    Gao, Lingyuan and Shen, Yijie and Prokhorenko, Sergei and Nahas, Yousra and Bellaiche, Laurent , journal=. Poincar. 2025 , publisher=

    2025

  29. [29]

    Nature Communications , volume=

    Observation of switchable polar skyrmion bubbles down to the atomic layers in van der Waals ferroelectric CuInP2S6 , author=. Nature Communications , volume=. 2025 , publisher=

    2025

  30. [30]

    Nature , volume=

    High-density switchable skyrmion-like polar nanodomains integrated on silicon , author=. Nature , volume=. 2022 , publisher=

    2022

  31. [31]

    Nature Materials , volume=

    Mechanically liberating polarization bubbles in van der Waals ferroelectrics , author=. Nature Materials , volume=. 2025 , publisher=

    2025

  32. [32]

    Nature Nanotechnology , volume=

    Topological properties and dynamics of magnetic skyrmions , author=. Nature Nanotechnology , volume=. 2013 , publisher=

    2013

  33. [33]

    Nature Communications , volume=

    Giant electric field-induced second harmonic generation in polar skyrmions , author=. Nature Communications , volume=. 2024 , publisher=

    2024

  34. [34]

    Nature Physics , volume=

    Terahertz excitation of collective dynamics of polar skyrmions over a broad temperature range , author=. Nature Physics , volume=. 2025 , publisher=

    2025

  35. [35]

    Nature Communications , volume=

    Terahertz-field activation of polar skyrons , author=. Nature Communications , volume=. 2025 , publisher=

    2025

  36. [36]

    Nature Nanotechnology , volume=

    Skyrmions on the track , author=. Nature Nanotechnology , volume=. 2013 , publisher=

    2013

  37. [37]

    Scientific Reports , volume=

    A strategy for the design of skyrmion racetrack memories , author=. Scientific Reports , volume=. 2014 , publisher=

    2014

  38. [38]

    APL Materials , volume=

    Skyrmion devices for memory and logic applications , author=. APL Materials , volume=. 2021 , publisher=

    2021

  39. [39]

    Science Advances , volume=

    Theoretical guidelines to create and tune electric skyrmion bubbles , author=. Science Advances , volume=. 2019 , publisher=

    2019

  40. [40]

    Physical Review Applied , volume=

    Electrical control of skyrmion density via skyrmion-stripe transformation , author=. Physical Review Applied , volume=. 2020 , publisher=

    2020

  41. [41]

    Nature Materials , volume=

    Ferroelectrically tunable magnetic skyrmions in ultrathin oxide heterostructures , author=. Nature Materials , volume=. 2018 , publisher=

    2018

  42. [42]

    Journal of Physics D: Applied Physics , volume=

    Size and density control of skyrmions with picometer CoFeB thickness variations—observation of zero-field skyrmions and skyrmion merging , author=. Journal of Physics D: Applied Physics , volume=. 2023 , publisher=

    2023

  43. [43]

    IEEE Access , year=

    Controlling the skyrmion density and size for quantized convolutional neural network , author=. IEEE Access , year=

  44. [44]

    arXiv preprint arXiv:2504.11013 , year=

    Effective Theory of Ultrafast Skyrmion Nucleation , author=. arXiv preprint arXiv:2504.11013 , year=

    arXiv

  45. [45]

    ACS Photonics , volume=

    Orbital angular momentum in nanoplasmonic vortices , author=. ACS Photonics , volume=. 2023 , publisher=

    2023

  46. [46]

    Applied Physics Reviews , volume=

    Advances in ultrafast plasmonics , author=. Applied Physics Reviews , volume=. 2023 , publisher=

    2023

  47. [47]

    Acta Materialia , volume=

    Entangled polarizations in ferroelectrics: A focused review of polar topologies , author=. Acta Materialia , volume=. 2023 , publisher=

    2023

  48. [48]

    Physical Review B , volume=

    Quasihexagonal arrays of electric-skyrmion bubbles in thin-film ferroelectrics: Pattern formation and structure , author=. Physical Review B , volume=. 2024 , publisher=

    2024

  49. [49]

    Electromechanical behavior of

    Garcia, Alberto and Vanderbilt, David , journal=. Electromechanical behavior of. 1998 , publisher=

    1998

  50. [50]

    Nature Electronics , volume=

    Creation and annihilation of non-volatile fixed magnetic skyrmions using voltage control of magnetic anisotropy , author=. Nature Electronics , volume=. 2020 , publisher=

    2020

  51. [51]

    Nature , volume=

    All-electrical skyrmionic magnetic tunnel junction , author=. Nature , volume=. 2024 , publisher=

    2024

  52. [52]

    Nano Letters , volume=

    Creation of magnetic skyrmion bubble lattices by ultrafast laser in ultrathin films , author=. Nano Letters , volume=. 2018 , publisher=

    2018

  53. [53]

    Nuclear Physics B , volume=

    Definition and statistical distributions of a topological number in the lattice O (3) -model , author=. Nuclear Physics B , volume=. 1981 , publisher=

    1981

  54. [54]

    Optics express , volume=

    Graphene/liquid crystal based terahertz phase shifters , author=. Optics express , volume=. 2013 , publisher=

    2013

  55. [55]

    Review of Scientific Instruments , volume=

    Simultaneous direct measurement of the electrocaloric and dielectric dynamics of ferroelectrics with microsecond temporal resolution , author=. Review of Scientific Instruments , volume=. 2023 , publisher=

    2023

  56. [56]

    Light: Science & Applications , volume=

    Broadband tunable liquid crystal terahertz waveplates driven with porous graphene electrodes , author=. Light: Science & Applications , volume=. 2015 , publisher=

    2015

  57. [57]

    arXiv preprint arXiv:2601.16604 , year=

    Enhanced Terahertz Photoresponse via Acoustic Plasmon Cavity Resonances in Scalable Graphene , author=. arXiv preprint arXiv:2601.16604 , year=

    arXiv

  58. [58]

    Journal of the American Ceramic Society , volume=

    Improvement of reliability and dielectric breakdown strength of Nb-doped lead zirconate titanate films via microstructure control of seed , author=. Journal of the American Ceramic Society , volume=. 2019 , publisher=

    2019

  59. [59]

    Current Applied Physics , volume=

    Experimental evidence of breakdown strength and its effect on energy-storage performance in normal and relaxor ferroelectric films , author=. Current Applied Physics , volume=. 2019 , publisher=

    2019

  60. [60]

    Ferroelectrics , volume=

    Dielectric characteristics of Pb (Zr, Ti) O3 films on MgO single crystal substrate by terahertz time domain spectroscopy , author=. Ferroelectrics , volume=. 2011 , publisher=

    2011

  61. [61]

    Proposed universal relationship between dielectric breakdown and dielectric constant , author=. Digest. International Electron Devices Meeting, , pages=. 2002 , organization=

    2002