Double-pulse control of all optical magnetization reversal in Tb/Co multilayers

Alexey V. Kimel; Dinar Khusyainov; Johan H. Mentink; Liliana D. Buda-Prejbeanu; Lukas K\"orber; Quoc-Trung Trinh; Rein Liefferink; Ricardo C. Sousa; Sheng Li; Theo Rasing

arxiv: 2607.00648 · v1 · pith:HANL3L5Fnew · submitted 2026-07-01 · ❄️ cond-mat.mtrl-sci

Double-pulse control of all optical magnetization reversal in Tb/Co multilayers

Sheng Li , Dinar Khusyainov , Rein Liefferink , Lukas K\"orber , Quoc-Trung Trinh , Ricardo C. Sousa , Liliana D. Buda-Prejbeanu , Johan H. Mentink

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Theo Rasing Alexey V. Kimel

This is my paper

Pith reviewed 2026-07-02 10:21 UTC · model grok-4.3

classification ❄️ cond-mat.mtrl-sci

keywords all-optical magnetization reversalTb/Co multilayersdouble-pulse excitationultrafast dynamicsmagnetic anisotropy recoveryprecessional switchingdomain pattern control

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The pith

Varying the delay between two laser pulses controls the final magnetic domain pattern in Tb/Co multilayers after all-optical reversal.

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

The paper examines how double femtosecond laser pulses induce magnetization reversal in Tb/Co multilayers, which normally produce ring-shaped switched regions. The pulses first quench the magnetic anisotropy through heating and then allow its recovery, which drives precessional switching of the magnetization. Adjusting the time delay between the two pulses intervenes in this recovery at different stages. Experiments and numerical simulations both show that this timing change alters the final domain pattern that results. The work establishes a temporal control method over the reversal process in addition to the spatial profile of the light.

Core claim

Double-pulse laser excitation with tunable delay between pulses manipulates the recovery of magnetic anisotropy after heat-induced quenching, thereby controlling the precessional magnetization switching and the resulting domain patterns in the multilayers.

What carries the argument

Double-pulse excitation with adjustable temporal delay that intervenes during the anisotropy recovery phase of precessional switching.

Load-bearing premise

The ring-shaped switching arises because heat quenches the anisotropy and its subsequent recovery drives precessional magnetization switching.

What would settle it

Experiments in which changing the pulse delay produces no measurable change in the final domain pattern, or numerical models lacking anisotropy recovery that still reproduce the observed control.

Figures

Figures reproduced from arXiv: 2607.00648 by Alexey V. Kimel, Dinar Khusyainov, Johan H. Mentink, Liliana D. Buda-Prejbeanu, Lukas K\"orber, Quoc-Trung Trinh, Rein Liefferink, Ricardo C. Sousa, Sheng Li, Theo Rasing.

**Figure 2.** Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗

**Figure 3.** Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗

**Figure 4.** Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p007_4.png] view at source ↗

read the original abstract

Recent experiments have shown that femtosecond laser pulse with a Gaussian intensity profile can induce magnetization reversal in Tb/Co multilayers with a ring-shaped switching pattern within the laser-irradiated area. Here, we investigate the ultrafast magnetization dynamics leading to such a ring-shaped switching by using double-pulse laser excitation. The laser pulses cause heat-induced quenching and subsequent recovery of the magnetic anisotropy in the multilayers and drive the precessional magnetization switching in the magnetic multilayers. By adjusting the delay between the two pump pulses, we demonstrate that the recovery process can be manipulated and show, experimentally and numerically, that this allows control over the final magnetic domain pattern.

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.

Desk Editor's Note private letter to a colleague

Double-pulse delay gives a workable control knob for ring-shaped all-optical switching patterns in Tb/Co, with matching experiment and simulation.

read the letter

The main point is that a second laser pulse with tunable delay lets them steer the final domain pattern in these Tb/Co multilayers after the first pulse has already started the reversal process.

The advance is straightforward: single-pulse experiments already produce ring-shaped switched regions because the Gaussian beam creates a radial temperature profile that quenches anisotropy and triggers precession. Adding the second pulse and changing its arrival time alters how far the anisotropy has recovered when the second heat load hits, which changes the precessional trajectory and therefore the final switched area. The abstract reports that both the measured patterns and the numerical runs track this dependence on delay.

That combination of experiment and modeling is the part that holds up. It turns an observed phenomenon into something that can be dialed in, which is a concrete step beyond just demonstrating reversal.

The weaker part is the level of detail available. Without the methods section it is hard to judge how closely the simulations match the data in absolute terms or how sensitive the outcome is to the anisotropy recovery time constants. If those parameters were adjusted to fit rather than taken from independent measurements, the numerical support would be less decisive, though the abstract gives no sign of that.

The work is aimed at the ultrafast magnetism community and anyone thinking about light-controlled magnetic bits. A reader already following all-optical switching will see a useful new experimental handle. The paper is coherent on its own terms and reports a falsifiable control result, so it clears the bar for peer review even if the full data tables would need close checking.

Referee Report

2 major / 2 minor

Summary. The manuscript investigates ultrafast magnetization dynamics in Tb/Co multilayers under double-pulse femtosecond laser excitation. It claims that the pulses induce heat-driven quenching and recovery of magnetic anisotropy, which drives precessional switching and produces a ring-shaped reversal pattern; by varying the temporal delay between the two pulses, the recovery process can be manipulated to control the final magnetic domain pattern. Both experimental observations and numerical simulations are presented in support of this delay-based control.

Significance. If the central claim holds, the work demonstrates a practical experimental handle (pulse delay) for shaping all-optical switching outcomes in a materials system already known for single-pulse ring reversal. The combination of experiment and simulation is a strength, as it directly links the observed domain control to the proposed anisotropy-recovery mechanism. This could inform design of ultrafast magnetic devices, though the result remains specific to the Tb/Co multilayer geometry and Gaussian excitation profile studied.

major comments (2)

[Methods] Methods (experimental): the manuscript provides no quantitative details on laser fluence, pulse duration, spot size, or the magneto-optical imaging technique used to extract domain patterns; without these, it is impossible to assess whether the reported delay dependence is reproducible or sensitive to small variations in excitation conditions.
[Numerical simulations] Numerical simulations: the model for temperature-dependent anisotropy recovery and its coupling to the Landau-Lifshitz-Gilbert dynamics is not specified (e.g., functional form of K(T), damping value, or how the two-pulse heat profile is implemented); this leaves the claim that delay directly controls precessional switching without a clear route to independent verification.

minor comments (2)

[Abstract] The abstract states the mechanism (heat-induced quenching and recovery driving precessional switching) without a forward reference to the section where this is quantified or tested.
[Figures] Figure captions should explicitly state the number of experimental repetitions or simulation runs underlying each domain image.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments and positive assessment of the significance of our work. We address each major comment below and will revise the manuscript accordingly to improve reproducibility and clarity.

read point-by-point responses

Referee: [Methods] Methods (experimental): the manuscript provides no quantitative details on laser fluence, pulse duration, spot size, or the magneto-optical imaging technique used to extract domain patterns; without these, it is impossible to assess whether the reported delay dependence is reproducible or sensitive to small variations in excitation conditions.

Authors: We agree that quantitative experimental parameters are essential for reproducibility. In the revised manuscript we will add a dedicated Methods section that specifies the laser fluences employed, pulse durations, spot sizes, and the magneto-optical Kerr imaging setup together with the procedure used to extract domain patterns. revision: yes
Referee: [Numerical simulations] Numerical simulations: the model for temperature-dependent anisotropy recovery and its coupling to the Landau-Lifshitz-Gilbert dynamics is not specified (e.g., functional form of K(T), damping value, or how the two-pulse heat profile is implemented); this leaves the claim that delay directly controls precessional switching without a clear route to independent verification.

Authors: We acknowledge that the simulation details were not fully specified. The revised manuscript will include an expanded description of the numerical model, explicitly stating the functional form of K(T), the Gilbert damping parameter, and the implementation of the two-pulse heat profile within the LLG framework. revision: yes

Circularity Check

0 steps flagged

No significant circularity

full rationale

The paper reports an experimental and numerical demonstration that varying the delay between two pump pulses manipulates anisotropy recovery to control final magnetic domain patterns via precessional switching. The abstract and described approach directly test this mechanism by adjusting an external experimental parameter (pulse delay) and observing the resulting pattern changes, with no equations, fitted parameters, or self-citations presented that reduce any prediction to a quantity defined by the inputs themselves. The derivation chain is therefore self-contained against external benchmarks and does not exhibit any of the enumerated circularity patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

From the abstract alone, no explicit free parameters, axioms, or invented entities are identified; the work relies on established concepts of heat-induced quenching, anisotropy recovery, and precessional switching without introducing new entities.

pith-pipeline@v0.9.1-grok · 5685 in / 1147 out tokens · 39873 ms · 2026-07-02T10:21:28.755919+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

5 extracted references · 1 canonical work pages

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C., Dieny, B

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Kimel, A. V . & Kirilyuk, A., Phys Rev Res 5, 023163 (2023). 3 Byrnes, S. J., arXiv preprint arXiv:1603.02720 (2016). 4 Polyanskiy, M. N., Sci Data 11 (2024). 5 Erskine, J. L., Blake, G. A. & Flaten, C. J., J Opt Soc Am 64, 1332 (1974). 6 Salomoni, D., Peng, Y ., Farcis, L., Auffret, S., Hehn, M., Malinowski, G.,

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D., Sousa, R

Mangin, S., Dieny, B., Buda-Prejbeanu, L. D., Sousa, R. C. & Prejbeanu, I. L., Phys Rev Appl 20, 034070 (2023). 7 Avilés-Félix, L., Farcis, L., Jin, Z., Alvaro -Gómez, L., Li, G., Yamada, K. T.,

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V ., Rasing, T., Dieny, B., Sousa, R

Kirilyuk, A., Kimel, A. V ., Rasing, T., Dieny, B., Sousa, R. C., Prejbeanu, I. L. & Buda-Prejbeanu, L. D., Sci Rep 11, 6576 (2021). 8 Blank, T. G. H., Hermanussen, S., Lichtenberg, T., Rasing, T., Kirilyuk, A.,

2021
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& Kimel, A., Adv Mater Interfaces 9, 202201283 (2022)

Koopmans, B. & Kimel, A., Adv Mater Interfaces 9, 202201283 (2022)

2022

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C., Dieny, B

Sousa, R. C., Dieny, B. & Prejbeanu, I. L., Sci Rep 10, 5211 (2020). 2 Mishra, K., Blank, T. G. H., Davies, C. S., Avilés-Félix, L., Salomoni, D., Buda-

2020

[2] [2]

Kimel, A. V . & Kirilyuk, A., Phys Rev Res 5, 023163 (2023). 3 Byrnes, S. J., arXiv preprint arXiv:1603.02720 (2016). 4 Polyanskiy, M. N., Sci Data 11 (2024). 5 Erskine, J. L., Blake, G. A. & Flaten, C. J., J Opt Soc Am 64, 1332 (1974). 6 Salomoni, D., Peng, Y ., Farcis, L., Auffret, S., Hehn, M., Malinowski, G.,

work page arXiv 2023

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D., Sousa, R

Mangin, S., Dieny, B., Buda-Prejbeanu, L. D., Sousa, R. C. & Prejbeanu, I. L., Phys Rev Appl 20, 034070 (2023). 7 Avilés-Félix, L., Farcis, L., Jin, Z., Alvaro -Gómez, L., Li, G., Yamada, K. T.,

2023

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V ., Rasing, T., Dieny, B., Sousa, R

Kirilyuk, A., Kimel, A. V ., Rasing, T., Dieny, B., Sousa, R. C., Prejbeanu, I. L. & Buda-Prejbeanu, L. D., Sci Rep 11, 6576 (2021). 8 Blank, T. G. H., Hermanussen, S., Lichtenberg, T., Rasing, T., Kirilyuk, A.,

2021

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& Kimel, A., Adv Mater Interfaces 9, 202201283 (2022)

Koopmans, B. & Kimel, A., Adv Mater Interfaces 9, 202201283 (2022)

2022