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Skyrmion motion in a synthetic antiferromagnet driven by asymmetric spin wave emission

T0 review · 4 major / 5 minor · reviewed 2026-08-08 · deepseek-v4-flash

Pith's one-line read By micromagnetic simulation, this paper shows that a skyrmion pair in a synthetic antiferromagnet can be propelled along a wiggling straight path by global magnetic fields alone — a static in-plane field together with an out-of-plane…

desk verdict A careful simulation study with a genuinely new mechanism and a clear resonance signature—but the PBC effects on quantitative velocities are unquantified and should be checked before the numbers are trusted. read the letter →

arxiv 2502.08338 v2 pith:73WKBZAA submitted 2025-02-12 cond-mat.mes-hall

classification cond-mat.mes-hall
keywords skyrmionsyntheticantiferromagnetmicromagneticsimulationbreathingmodespinwaveemissionmicrowavefieldinterlayerexchangecouplingmotion
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper argues that skyrmions in a synthetic antiferromagnet — two ferromagnetic layers coupled antiferromagnetically through a spacer — can be moved without any electrical current, using only spatially uniform magnetic fields. An out-of-plane microwave field makes the coupled pair's radius 'breathe,' emitting spin waves; a static in-plane field breaks the emission symmetry, and momentum conservation then pushes the skyrmions along a wiggling path at a few metres per second. The velocity peaks sharply when the drive matches the pair's out-of-phase breathing mode (about 57 GHz at an interlayer coupling of $J_\mathrm{RKKY}=-0.3\ \mathrm{mJ/m^2}$) and vanishes at the in-phase mode (about 14 GHz). The paper identifies a threshold radial-oscillation amplitude of about 0.44 nm below which the emitted spin waves are too weak to move the skyrmions, which also explains why electric-field driving couples to the lower mode while magnetic-field driving couples to the higher one. If correct, this is a current-free, frequency-tunable propulsion method relevant to racetrack memory and skyrmion-based computing.

What carries the argument

The load-bearing objects are the two collective breathing modes of the antiferromagnetically coupled skyrmion pair — the in-phase mode at about 14.3 GHz, where both radii oscillate together, and the out-of-phase mode at about 57.4 GHz, where they oscillate against each other — characterised through the power spectral density of the layer magnetisations after a sinc-pulse excitation. The propulsion mechanism is asymmetric spin-wave emission: the oscillating radius 'knocks' the surrounding magnetisation and radiates spin waves at the maxima of expansion, and the static in-plane field deforms the skyrmions so emission is directional, creating a net momentum transfer that moves the pair perpendicular to the in-plane field. The argument is carried by two derived quantities: the peak-to-peak radius variation $\Delta r_\mathrm{Sk}$, which must exceed about 0.44 nm for motion to start, and the velocity-versus-frequency curve, whose peak is coupled to the out-of-phase breathing peak and also to a higher-frequency (around 75 GHz) hybrid of the breathing mode with a spin-wave mode of the spins canted by the in-plane field; a comparison using anisotropy modulation and spin-transfer torque shows that which mode drives motion depends on the excitation mechanism's symmetry.

What would settle it

Re-run the motion simulation at 57.4 GHz with a 20 mT microwave field and a 0.5 T in-plane field in a cell four times larger (1.6 microns) or with absorbing boundary layers: if the steady-state y-velocity departs from about 6 m/s by more than the run-to-run spread, or if the ~1 GHz transverse wiggle vanishes, then the periodic-image coupling flagged by the authors is doing real work and their quantitative velocities need correction.

Watch

Extended reading notes

Core claim

The central claim is that asymmetric spin-wave emission from a breathing skyrmion pair is a complete propulsion mechanism in synthetic antiferromagnets: an out-of-plane microwave field excites oscillations of the skyrmion radius, and when a static in-plane field is added the two skyrmions deform so the emitted spin waves no longer balance, and momentum conservation drives the pair transversely — the paper notes this wiggle-like motion is the first report of its kind in a synthetic antiferromagnet. In simulation the velocity peaks sharply at the intrinsic out-of-phase breathing-mode frequency (57.4 GHz at $J_\mathrm{RKKY}=-0.3\ \mathrm{mJ/m^2}$), overlapping the mode's spectral peak, and vanishes at the in-phase mode because there the radius variation (0.286 nm at 20 mT) falls below the roughly 0.44 nm threshold needed to launch motion. The paper further claims that the apparent dependence of velocity on interlayer exchange coupling seen in earlier electric-field work is not fundamental: at resonance the peak velocity is set by the breathing amplitude, which the coupling constrains, producing an inverse-cube fall-off for strong coupling and two regimes of instability at weaker coupling, and for decompensated layers the out-of-phase-mode velocity is maximal at full compensation while the in-phase mode only becomes active once the layers are sufficiently unbalanced.

Load-bearing premise

The load-bearing premise is that the simulated 400 nm periodic cell faithfully captures the propulsion: spin waves emitted by the skyrmion wrap around the periodic boundaries and can re-encounter the moving skyrmion, and the paper does not check whether that recirculation changes the net momentum transfer or the reported velocities.

Editorial extensions

If this is right

  • Racetrack-style skyrmion devices could be operated without passing current through the magnetic stack; only a global microwave field and a static in-plane field are needed, so insulating or high-resistance materials remain usable.
  • Skyrmion speed becomes tunable by microwave frequency: maximum speed is achieved by locking the drive to the out-of-phase breathing frequency, which itself shifts with the interlayer exchange coupling, giving both a frequency knob and a materials knob.
  • The three regimes of interlayer coupling (annihilation below about 0.03 mJ/m^2, unstable motion up to about 0.1 mJ/m^2, then a stable inverse-cube fall-off) define a design window, and the coupling strengths reported in experimental synthetic antiferromagnets fall inside the stable-motion range.
  • There is an intrinsic power threshold: below about 3 mT microwave amplitude, corresponding to a radius variation of about 0.44 nm, there is no motion at all, and only above that threshold does velocity rise linearly with driving field.
  • In synthetic ferrimagnets with imperfect layer compensation, motion persists over a wide range of imbalance, with the out-of-phase-mode velocity maximal at full compensation and the in-phase mode becoming active as the layers unbalance — useful because real samples are rarely perfectly compensated.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The periodic-boundary interference the authors flag in the Fig. 5 caption leaves an open quantitative question: emitted spin waves wrap around the 400 nm cell and can re-encounter the moving skyrmion, and the paper does not test whether this recirculation changes the net momentum transfer or the reported ~6 m/s velocities; a larger cell or absorbing boundaries would settle it.
  • The 0.44 nm radius-variation threshold is established for one set of magnetic parameters; if it turns out to be a material-independent criterion it would give experimentalists a single number to design around, but the paper does not claim universality.
  • Because the out-of-phase breathing frequency shifts with interlayer coupling, stacks with different coupling strengths respond to different microwave frequencies, which suggests a frequency-addressing scheme for dense skyrmion arrays — an application the paper does not pursue.
  • The ~1 GHz transverse wiggle means the propulsion is intrinsically oscillatory at a microwave-independent rate; exploiting that oscillation as an on-chip clock or mixer signal is a speculative extension beyond the paper's stated scope.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. This manuscript uses MUMAX3 micromagnetic simulations to propose and characterize a method of moving skyrmions in synthetic antiferromagnets (SAFs) using only global magnetic fields: a static in-plane field combined with an out-of-plane microwave field. The authors show that the microwave field drives skyrmion breathing modes, the in-plane field breaks symmetry, and the resulting asymmetric spin-wave emission propels the skyrmion pair in a wiggling trajectory. They report a velocity peak near the out-of-phase breathing-mode frequency (57.4 GHz for J_RKKY = -0.3 mJ/m^2), a threshold radius variation of about 0.44 nm below which no motion occurs, three regimes of behavior as a function of interlayer exchange coupling, and extensions to synthetic ferrimagnets, electric-field driving, and spin-transfer-torque driving. The manuscript includes extensive parameter sweeps and comparisons to previous work.

Significance. If correct, this is a valuable contribution: it demonstrates a mechanism for driving SAF skyrmions with global fields, avoiding the need for conductive samples or current injection, and it connects skyrmion velocity to a specific breathing mode, providing a frequency-based tuning knobs. The paper is thorough in its parametric coverage: it studies the exchange-coupling dependence, layer decompensation, electric-field excitation, and STT excitation, and it explicitly attempts to separate the role of breathing-mode amplitude from the driving mechanism. The identification of the velocity peak with the out-of-phase breathing mode and the later use of a radius-variation threshold to explain the absence of motion at the in-phase mode are physically appealing and internally consistent. However, the quantitative central claims—the 57.4 GHz resonance coupling, the steady velocity of roughly 6 m/s, and the 0.44 nm threshold—rest on simulations with periodic boundary conditions in which emitted spin waves recirculate around the simulation cell; the authors acknowledge interference but do not provide finite-size controls.

major comments (4)
  1. [Sec. II and Fig. 5 caption]
  2. [Sec. IV C and Sec. VI]
  3. [Sec. IV B and Fig. 4]
  4. [Sec. IV C and Fig. 5(m)]
minor comments (5)
  1. [Eq. (1)]
  2. [Fig. 1 caption]
  3. [Supplementary Note S4]
  4. [Sec. IV B]
  5. [Sec. II]

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the velocity-frequency resonance match and the radius-variation threshold are independently computed results, not fitted inputs renamed as predictions.

full rationale

The paper's central derivation chain is self-contained and simulation-based. The breathing-mode peak frequencies (14.3 GHz and 57.4 GHz) are extracted from sinc-pulse excited PSD runs, while the velocity-vs-frequency sweeps in Fig. 4 are separate simulations in which the drive frequency is scanned over a broad range; the overlap between the velocity peak and the out-of-phase breathing-mode peak is a measured correlation, not a re-insertion of the fitted Lorentzian peak into the velocity data. Likewise, the 0.44 nm radius-variation threshold is obtained by simultaneous amplitude sweeps of the driving field (velocity in Fig. 5(m) and radius variation in Fig. 5(n)), and the threshold is then applied independently to the electric-field-driven cases in Sec. VI, where the radius variations (13.6 nm and 0.18 nm) are computed from separate simulations. The self-citations to Refs. [39, 40, 52, 53] provide background, interpretation, and comparison material, but the load-bearing quantitative claims are computed in the present simulations and do not reduce to those citations. The acknowledged periodic-boundary-condition interference in the Fig. 5 caption is a finite-size and accuracy concern that could affect the reported velocities, but it is not a circularity: the inputs do not by construction determine the outputs. No fitted parameter is renamed as a prediction, and no central claim is equivalent to its own input.

Assumptions & free parameters 0 free parameters · 5 assumptions · 0 invented entities

The central claims rest on standard micromagnetics (LLG with exchange, anisotropy, DMI, demagnetisation and Zeeman terms), a bilinear interlayer coupling model, periodic boundary conditions, and the Slonczewski STT model. The momentum-transfer mechanism of spin-wave-driven motion is taken from prior work and not derived here. Periodic-boundary interference is acknowledged but its effect on the reported velocities is untested.

assumptions (5)
  • domain assumption The Landau-Lifshitz-Gilbert equation with the stated micromagnetic energy functional captures the dynamics of the SAF skyrmion pair.
    Sec. II Eqs. (1)-(5); the simulation parameters are taken from literature for DMI multilayers (Ref [51]).
  • domain assumption The interlayer exchange coupling is represented by URKKY = -J_RKKY ∫(m1·m2)dV, a local bilinear coupling across the non-magnetic spacer.
    Sec. II Eq. (5); real RKKY coupling is oscillatory and thickness-dependent, which could shift mode frequencies.
  • domain assumption Periodic boundary conditions in the x-y plane do not materially affect the skyrmion breathing spectrum or the driven motion.
    Sec. III B uses PBC to remove edge modes; Sec. IV C and Fig. 5 note 'some interference' from PBC, but no finite-size study is performed.
  • domain assumption The skyrmion motion is caused by momentum transfer from asymmetrically emitted spin waves, as established in Refs [16, 45].
    Invoked in Sec. I and Sec. IV C; the paper does not derive the momentum balance, only visualises the anisotropic emission.
  • domain assumption The Slonczewski STT with damping-like torque and fixed layer polarisation along z correctly represents CPP current excitation across the Ru spacer.
    Sec. VII Eqs. (11)-(13); the Ru spin diffusion length of 14 nm (Ref [58]) justifies the CPP geometry.

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Pith. "Pith review of Skyrmion motion in a synthetic antiferromagnet driven by asymmetric spin wave emission." pith.science (2026). https://pith.science/paper/73WKBZAA

@misc{pith2026250208338,
  author       = {Pith},
  title        = {Pith review of: Skyrmion motion in a synthetic antiferromagnet driven by asymmetric spin wave emission},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/73WKBZAA}},
  note         = {Machine review of arXiv:2502.08338}
}
read the original abstract

Skyrmions have been proposed as new information carriers in racetrack memory devices. To realise such devices, a small size; high speed of propagation; and minimal skyrmion Hall angle are required. Synthetic antiferromagnets (SAFs) present the ideal materials system to realise these aims. In this work, we use micromagnetic simulations to propose a new method for manipulating them using exclusively global magnetic fields. An out-of-plane microwave field induces oscillations in the skyrmions radius which in turn emits spin waves. When a static in-plane field is added, this breaks the symmetry of the skyrmions and causes asymmetric spin wave emission. This in turn drives motion of the skyrmions, with the fastest velocities observed at the frequency of the intrinsic out-of-phase breathing mode of the pair of skyrmions. This behaviour is investigated over a range of experimentally realistic antiferromagnetic interlayer exchange coupling strengths, and the results compared to previous works studying similar motion driven with an oscillating electric field. Through this the true effect of varying the exchange coupling strength is determined, and greater insight is gained into the mechanism of skyrmion motion. These results will help to inform the design of future novel computing architectures based on the dynamics of skyrmions in synthetic antiferromagnets.

Figures

Figures reproduced from arXiv: 2502.08338 by the authors.

Figure 1
Figure 1. FIG. 1. Illustration of simulation set-up and characterisation of skyrmi [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Skyrmion frequency response as a function of frequency and ant [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 2
Figure 2. Fig. 2(a) shows an illustration of the skyrmion frequen [PITH_FULL_IMAGE:figures/full_fig_p010_2.png] view at source ↗
Figures from the paper (7 more)
Figure 3
Figure 3. Figure 3: FIG. 3. In-plane field-driven skyrmion motion in a field of 0.5 T along [PITH_FULL_IMAGE:figures/full_fig_p011_3.png]
Figure 4
Figure 4. Figure 4: FIG. 4. Velocities of the two skyrmions as a function of frequency of t [PITH_FULL_IMAGE:figures/full_fig_p013_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. (a,b) Snapshots of the [PITH_FULL_IMAGE:figures/full_fig_p015_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. (a) Skyrmion velocity as a function of frequency plotted for var [PITH_FULL_IMAGE:figures/full_fig_p019_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. Breathing modes and motion as a function of decompensation of one of th [PITH_FULL_IMAGE:figures/full_fig_p021_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Examination of the effects of electric field on the skyrmion breat [PITH_FULL_IMAGE:figures/full_fig_p025_8.png]
Figure 9
Figure 9. Figure 9: FIG. 9. (a). Illustration of the current perpendicular to plane (CPP [PITH_FULL_IMAGE:figures/full_fig_p028_9.png]

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Works this paper leans on

59 extracted references · 55 canonical work pages

  1. [1]

    Nagaosa and Y

    N. Nagaosa and Y. Tokura, Topological properties and dynamics of magnetic skyrmion s, Nature Nanotechnology 8, 899 (2013)

  2. [2]

    Everschor-Sitte, J

    K. Everschor-Sitte, J. Masell, R. M. Reeve, and M. Kl¨ aui, Pers pective: Magnetic skyrmions—overview of recent progress in an active research field, Jou rnal of Applied Physics 124, 240901 (2018)

  3. [3]

    C. H. Marrows and K. Zeissler, Perspective on skyrmion spintroni cs, Applied Physics Letters 119, 250502 (2021)

  4. [4]

    Finocchio, F

    G. Finocchio, F. B¨ uttner, R. Tomasello, M. Carpentieri, and M. K l¨ aui, Magnetic skyrmions: from fundamental to applications, Journal of Physics D: Applied Physic s 49, 423001 (2016)

  5. [5]

    Tomasello, E

    R. Tomasello, E. Martinez, R. Zivieri, L. Torres, M. Carpentieri, and G. Finocchio, A strategy for the design of skyrmion racetrack memories, Scientific Reports 4, 6784 (2014). 31

  6. [6]

    K. M. Song, J.-S. Jeong, B. Pan, X. Zhang, J. Xia, S. Cha, T.-E. Park, K. Kim , S. Finizio, J. Raabe, J. Chang, Y. Zhou, W. Zhao, W. Kang, H. Ju, and S. Woo, Skyrmion-based ar tificial synapses for neuromorphic computing, Nature Electronics 3, 148 (2020)

  7. [7]

    C. H. Marrows, J. Barker, T. A. Moore, and T. Moorsom, Neuromorphic compu ting with spintronics, npj Spintronics 2, 12 (2024)

  8. [8]

    A. P. Petrovi´ c, C. Psaroudaki, P. Fischer, M. Garst, and C. Panagopoulos, Colloquium: Quan- tum properties and functionalities of magnetic skyrmions (2024), arXiv:2410.11427

Show all 59 references
  1. [9]

    Banerjee, C

    N. Banerjee, C. Bell, C. Ciccarelli, T. Hesjedal, F. Johnson, H. Kur ebayashi, T. A. Moore, C. Moutafis, H. L. Stern, I. J. Vera-Marun, J. Wade, C. Barton, M. R. Connoll y, N. J. Curson, K. Fallon, A. J. Fisher, D. A. Gangloff, W. Griggs, E. Linfield, C. H. Marrows, A. Rossi, F. ...

  2. [10]

    A. Fert, V. Cros, and J. Sampaio, Skyrmions on the track, Nature Nanotechnology 8, 152 (2013)

  3. [11]

    S. Woo, K. Litzius, B. Kr¨ uger, M.-Y. Im, L. Caretta, K. Richter, M. Mann, A. Krone, R. M. Reeve, M. Weigand, P. Agrawal, I. Lemesh, M.-A. Mawass, P. Fischer, M. Kl¨ aui, and G. S. D. Beach, Observation of room-temperature magnetic skyrmions and their c urrent-driven dy- nami...

  4. [12]

    Juge, S.-G

    R. Juge, S.-G. Je, D. d. S. Chaves, L. D. Buda-Prejbeanu, J. Pe˜ na Garcia, J. Nath, I. M. Miron, K. G. Rana, L. Aballe, M. Foerster, F. Genuzio, T. O. Mentes, A. Locatell i, F. Maccherozzi, S. S. Dhesi, M. Belmeguenai, Y. Roussign´ e, S. Auffret, S. Pizzini, G . Gaudin, J. Vog...

  5. [13]

    S. L. Zhang, W. W. Wang, D. M. Burn, H. Peng, H. Berger, A. Bauer, C. Pfleide rer, G. van der Laan, and T. Hesjedal, Manipulation of skyrmion motion by magnetic field gradien ts, Nature Communications 9, 2115 (2018)

  6. [14]

    C. Wang, D. Xiao, X. Chen, Y. Zhou, and Y. Liu, Manipulating and trapping skyr mions by magnetic field gradients, New Journal of Physics 19, 083008 (2017)

  7. [15]

    Moon, D.-H

    K.-W. Moon, D.-H. Kim, S.-G. Je, B. S. Chun, W. Kim, Z. Q. Qiu, S .-B. Choe, and C. Hwang, Skyrmion motion driven by oscillating magnetic field, Scientific Rep orts 6, 20360 (2016). 32

  8. [16]

    W. Wang, M. Beg, B. Zhang, W. Kuch, and H. Fangohr, Driving magnetic skyrm ions with microwave fields, Phys. Rev. B 92, 020403 (2015)

  9. [17]

    Everschor-Sitte and M

    K. Everschor-Sitte and M. Sitte, Real-space berry phases: Skyr mion soccer (invited), Journal of Applied Physics 115, 172602 (2014)

  10. [18]

    Jiang, X

    W. Jiang, X. Zhang, G. Yu, W. Zhang, X. Wang, M. Benjamin Jungfleisch, J. Pe arson, X. Cheng, O. Heinonen, K. L. Wang, Y. Zhou, A. Hoffmann, and S. te Velthuis, Dire ct observation of the skyrmion hall effect, Nature Physics 13, 162 (2017)

  11. [19]

    Litzius, I

    K. Litzius, I. Lemesh, B. Kr¨ uger, P. Bassirian, L. Caretta, K. Rich ter, F. B¨ uttner, K. Sato, O. A. Tretiakov, J. F¨ orster, R. M. Reeve, M. Weigand, I. Bykova, H. Stoll, G. Sch¨ utz, G. S. D. Beach, and M. Kl¨ aui, Skyrmion hall effect revealed by direct time-r esolved x-r...

  12. [20]

    Zeissler, S

    K. Zeissler, S. Finizio, C. Barton, A. J. Huxtable, J. Massey, J. Raab e, A. V. Sadovnikov, S. A. Nikitov, R. Brearton, T. Hesjedal, G. van der Laan, M. C. Rosamond, E. H. Li nfield, G. Burnell, and C. H. Marrows, Diameter-independent skyrmion hall angle observed in chiral magn...

  13. [21]

    Zhang, Y

    X. Zhang, Y. Zhou, and M. Ezawa, Magnetic bilayer-skyrmions without sk yrmion hall effect, Nature Communications 7, 10293 (2016)

  14. [22]

    R. A. Duine, K.-J. Lee, S. S. P. Parkin, and M. D. Stiles, Synthet ic antiferromagnetic spin- tronics, Nature Physics 14, 217 (2018)

  15. [23]

    Barker and O

    J. Barker and O. A. Tretiakov, Static and dynamical properties of antif erromagnetic skyrmions in the presence of applied current and temperature, Phys. Rev. Let t. 116, 147203 (2016)

  16. [24]

    B¨ uttner, I

    F. B¨ uttner, I. Lemesh, and G. S. D. Beach, Theory of isolated magneti c skyrmions: From fundamentals to room temperature applications, Scientific Reports 8, 4464 (2018)

  17. [25]

    Legrand, D

    W. Legrand, D. Maccariello, F. Ajejas, S. Collin, A. Vecchiola, K. Bouzeh ouane, N. Reyren, V. Cros, and A. Fert, Room-temperature stabilization of antiferromagnetic skyrmions in syn- thetic antiferromagnets, Nature Materials 19, 34 (2020)

  18. [26]

    R. Juge, N. Sisodia, J. U. Larra˜ naga, Q. Zhang, V. T. Pham, K. G. Rana, B. Sarpi , N. Mille, S. Stanescu, R. Belkhou, M.-A. Mawass, N. Novakovic-Marinkovic, F. K ronast, M. Weigand, J. Gr¨ afe, S. Wintz, S. Finizio, J. Raabe, L. Aballe, M. Foerster, M. B elmeguenai, L. D. Bu...

  19. [27]

    V. T. Pham, N. Sisodia, I. D. Manici, J. Urrestarazu-Larra˜ naga, K. Bairagi, J. Pelloux-Prayer, R. Guedas, L. D. Buda-Prejbeanu, S. Auffret, A. Locatelli, T. O. Mente¸ s, S. Pizzini, P. Kumar, A. Finco, V. Jacques, G. Gaudin, and O. Boulle, Fast current-induced s kyrmion motio...

  20. [28]

    Yang, K.-S

    S.-H. Yang, K.-S. Ryu, and S. Parkin, Domain-wall velocities of up to 750 m s-1 driven by exchange coupling torque in synthetic antiferromagnets, Nature Nanote chnology 10, 221 (2015)

  21. [29]

    Lepadatu, H

    S. Lepadatu, H. Saarikoski, R. Beacham, M. J. Benitez, T. A. Moore, G. Bu rnell, S. Sugimoto, D. Yesudas, M. C. Wheeler, J. Miguel, S. S. Dhesi, D. McGrouther, S. McVitie, G. Tatara, and C. H. Marrows, Synthetic ferrimagnet nanowires with very low cr itical current density for...

  22. [30]

    C. E. A. Barker, S. Finizio, E. Haltz, S. Mayr, P. M. Shepley, T. A. M oore, G. Burnell, J. Raabe, and C. H. Marrows, Domain wall motion at low current density in a s ynthetic antiferromagnet nanowire, Journal of Physics D: Applied Physics 56, 425002 (2023)

  23. [31]

    K. Wang, V. Bheemarasetty, and G. Xiao, Spin textures in synthetic ant iferromagnets: Chal- lenges, opportunities, and future directions, APL Materials 11, 070902 (2023)

  24. [32]

    T. Dohi, S. DuttaGupta, S. Fukami, and H. Ohno, Formation and current-i nduced motion of synthetic antiferromagnetic skyrmion bubbles, Nature Communication s 10, 5153 (2019)

  25. [33]

    Lonsky and A

    M. Lonsky and A. Hoffmann, Dynamic excitations of chiral magnetic textures , APL Materials 8, 100903 (2020)

  26. [34]

    Mochizuki, Spin-wave modes and their intense excitation e ffects in skyrmion crystals, Phys

    M. Mochizuki, Spin-wave modes and their intense excitation e ffects in skyrmion crystals, Phys. Rev. Lett. 108, 017601 (2012)

  27. [35]

    Onose, Y

    Y. Onose, Y. Okamura, S. Seki, S. Ishiwata, and Y. Tokura, Observation of magn etic excita- tions of skyrmion crystal in a helimagnetic insulator cu 2oseo3, Phys. Rev. Lett. 109, 037603 (2012)

  28. [36]

    J.-V. Kim, F. Garcia-Sanchez, J. a. Sampaio, C. Moreau-Luchaire, V. Cros, and A. Fert, Breathing modes of confined skyrmions in ultrathin magnetic dots, Phy s. Rev. B 90, 064410 (2014)

  29. [37]

    Satywali, V

    B. Satywali, V. P. Kravchuk, L. Pan, M. Raju, S. He, F. Ma, A. P. Petrov i´ c, M. Garst, and C. Panagopoulos, Microwave resonances of magnetic skyrmions in thin fil m multilayers, 34 Nature Communications 12, 1909 (2021)

  30. [38]

    Srivastava, Y

    T. Srivastava, Y. Sassi, F. Ajejas, A. Vecchiola, I. Ngouagnia Yemeli, H. Hur dequint, K. Bouze- houane, N. Reyren, V. Cros, T. Devolder, J.-V. Kim, and G. de Loubens, Res onant dynamics of three-dimensional skyrmionic textures in thin film multilaye rs, APL Materials 11, 061110 (2023)

  31. [39]

    Lonsky and A

    M. Lonsky and A. Hoffmann, Coupled skyrmion breathing modes in synthet ic ferri- and an- tiferromagnets, Phys. Rev. B 102, 104403 (2020)

  32. [40]

    C. E. A. Barker, E. Haltz, T. A. Moore, and C. H. Marrows, Breathing mode s of skyrmion strings in a synthetic antiferromagnet multilayer, Journal of Applie d Physics 133, 113901 (2023)

  33. [41]

    L. Xing, D. Hua, and W. Wang, Magnetic excitations of skyrmions in antiferrom agnetic- exchange coupled disks, Journal of Applied Physics 124, 123904 (2018)

  34. [42]

    J. Chen, J. Hu, and H. Yu, Chiral emission of exchange spin waves by magn etic skyrmions, ACS Nano 15, 4372 (2021)

  35. [43]

    S. A. D ´ ıaz, T. Hirosawa, D. Loss, and C. Psaroudaki, Spin wave radiation by a topological charge dipole, Nano Letters 20, 6556 (2020)

  36. [44]

    N. Tang, W. L. N. C. Liyanage, S. A. Montoya, S. Patel, L. J. Quigley, A. J. Grutt er, M. R. Fitzsimmons, S. Sinha, J. A. Borchers, E. E. Fullerton, L. DeBe er-Schmitt, and D. A. Gilbert, Skyrmion-excited spin-wave fractal networks, Advanced Materials 35, 2300416 (2023), https...

  37. [45]

    H. Y. Yuan, X. S. Wang, M.-H. Yung, and X. R. Wang, Wiggling skyrmion propagation un der parametric pumping, Phys. Rev. B 99, 014428 (2019)

  38. [46]

    L. Qiu, L. Shen, X. Zhang, Y. Zhou, G. Zhao, W. Xia, H.-B. Luo, and J. P. Liu, Inte rlayer coupling effect on skyrmion dynamics in synthetic antiferromagnets, Applied Physics Letters 118, 082403 (2021)

  39. [47]

    G¨ obel, I

    B. G¨ obel, I. Mertig, and O. A. Tretiakov, Beyond skyrmions: Revie w and perspectives of alternative magnetic quasiparticles, Physics Reports 895, 1 (2021), beyond skyrmions: Review and perspectives of alternative magnetic quasiparticles

  40. [48]

    C. Liu, F. Ai, S. Reisbick, A. Zong, A. Pofelski, M.-G. Han, F. Camino, C. Jing, V. Lomakin, and Y. Zhu, Correlated spin-wave generation and domain-wall oscillation in a topologically textured magnetic film, Nature Materials 10.1038/s41563-024-02085-7 (2025). 35

  41. [49]

    Girardi, S

    D. Girardi, S. Finizio, C. Donnelly, G. Rubini, S. Mayr, V. Levati , S. Cuccurullo, F. Maspero, J. Raabe, D. Petti, and E. Albisetti, Three-dimensional spin-wave dynamics, localization and interference in a synthetic antiferromagnet, Nature Communications 15, 3057 (2024)

  42. [50]

    Vansteenkiste, J

    A. Vansteenkiste, J. Leliaert, M. Dvornik, M. Helsen, F. Garcia-San chez, and B. Van Waeyen- berge, The design and verification of MuMax3, AIP Advances 4, 107133 (2014)

  43. [51]

    Jiang, G

    W. Jiang, G. Chen, K. Liu, J. Zang, S. G. te Velthuis, and A. Hoffmann, Sky rmions in magnetic multilayers, Physics Reports 704, 1 (2017)

  44. [52]

    C. E. A. Barker, K. Fallon, C. Barton, E. Haltz, T. P. Almeida, S. Villa, C. Kirkbride, F. Maccherozzi, B. Sarpi, S. S. Dhesi, D. McGrouther, S. McVitie, T . A. Moore, O. Kaza- kova, and C. H. Marrows, Phase coexistence and transitions between ant iferromagnetic and ferromagne...

  45. [53]

    Haltz, C

    E. Haltz, C. E. A. Barker, and C. H. Marrows, Statics and dynamics of skyr mions in balanced and unbalanced synthetic antiferromagnets (2023), arXiv:2309.03697 [cond-mat.mes -hall]

  46. [54]

    P. K. Mishra, M. Sravani, A. Bose, and S. Bhuktare, Voltage-controlled magnetic anisotropy- based spintronic devices for magnetic memory applications: Challenges and perspectives, Journal of Applied Physics 135, 220701 (2024)

  47. [55]

    Slonczewski, Current-driven excitation of magnetic multila yers, Journal of Magnetism and Magnetic Materials 159, L1 (1996)

    J. Slonczewski, Current-driven excitation of magnetic multila yers, Journal of Magnetism and Magnetic Materials 159, L1 (1996)

  48. [56]

    Berger, Emission of spin waves by a magnetic multilayer traver sed by a current, Phys

    L. Berger, Emission of spin waves by a magnetic multilayer traver sed by a current, Phys. Rev. B 54, 9353 (1996)

  49. [57]

    J. Xiao, A. Zangwill, and M. D. Stiles, Boltzmann test of slonczewski’s theory of spin-transfer torque, Phys. Rev. B 70, 172405 (2004)

  50. [58]

    K. Eid, R. Fonck, M. A. Darwish, J. Pratt, W. P., and J. Bass, Curren t-perpendicular-to-plane- magnetoresistance properties of ru and co/ru interfaces, Journal of Applie d Physics 91, 8102 (2002), https://pubs.aip.org/aip/jap/article-pdf/91/10/8102/19074680/8102 1 online.pdf....

  51. [75]

    005 GHz for the entire system and 76

    321 ± 0. 005 GHz for the entire system and 76 . 32 ± 0. 01 GHz and 74 . 212 ± 0. 004 GHz for the first and second layers respectively. These values align well with the higher-frequency peak in velocity observed in Fig. 4(a) in the main paper. FIG. S3. The replotted data of Fig....

Pith tools

Reviewed August 8, 2026 · model on record in the stance chip above.