Photoengineering the magnon spectrum in an insulating antiferromagnet

Nature Physics (2026)Cite this article In antiferromagnets, where quantum mechanical exchange interactions dictate spin behaviour, understanding the dynamics of magnons—collective spin wave excitations that naturally reach terahertz frequencies and supersonic velocities—is essential for both fundamental science and emerging technologies. Femtosecond optical pulses offer a powerful means to coherently excite these magnons across the full Brillouin zone and to manipulate their spectral characteristics. Yet, achieving such control has remained difficult, as it requires ultrafast and sustained tuning of the underlying exchange interaction. Here we demonstrate an optically driven renormalization of the terahertz magnon spectrum in the insulating antiferromagnet DyFeO₃. Our results show that this transformation arises from a substantial transient reduction of the exchange interaction within a nanoscale region near the surface. These findings reveal a route to light-induced, nanoscale control of antiferromagnetic spin dynamics, opening opportunities for reconfigurable, ultrafast magnonic and spintronic functionalities.This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any timeSubscribe to this journal Receive 12 print issues and online access $259.00 per yearonly $21.58 per issueBuy this articleUSD 39.95Prices may be subject to local taxes which are calculated during checkoutSource data for figures are publicly available via Zenodo at https://doi.org/10.5281/zenodo.18430301 (ref. 54). All other data that support the findings of this Article are available from the corresponding authors upon request. Source data are provided with this paper.The code used to simulate the magnetic dynamics is available from the corresponding authors upon reasonable request.Němec, P., Fiebig, M., Kampfrath, T. & Kimel, A. V. Antiferromagnetic opto-spintronics. Nat. Phys. 14, 229–241 (2018).Article Google Scholar Baltz, V. et al. Antiferromagnetic spintronics. Rev. Mod. Phys. 90, 015005 (2018).Article ADS MathSciNet Google Scholar Han, J., Cheng, R., Liu, L., Ohno, H. & Fukami, S. Coherent antiferromagnetic spintronics. Nat. Mater. 22, 684–695 (2023).Article ADS Google Scholar Dal Din, A., Amin, O. J., Wadley, P. & Edmonds, K. W. Antiferromagnetic spintronics and beyond. NPJ Spintron. 2, 25 (2024).Article Google Scholar Tzschaschel, C., Satoh, T. & Fiebig, M. Tracking the ultrafast motion of an antiferromagnetic order parameter. Nat. Commun. 10, 3995 (2019).Article ADS Google Scholar Bossini, D. et al. Macrospin dynamics in antiferromagnets triggered by sub-20 femtosecond injection of nanomagnons. Nat. Commun. 7, 10645 (2016).Article ADS Google Scholar Kainuma, R., Matsumoto, K., Ito, T. & Satoh, T. Sub-millimeter propagation of antiferromagnetic magnons via magnon-photon coupling. NPJ Spintron. 2, 31 (2024).Article Google Scholar Sun, Y. et al. Dipolar spin wave packet transport in a van der Waals antiferromagnet. Nat. Phys. 20, 794–800 (2024).Article Google Scholar Hortensius, J. R. et al. Coherent spin-wave transport in an antiferromagnet. Nat. Phys. 17, 1001–1006 (2021).Article Google Scholar Rongione, E. et al. Emission of coherent THz magnons in an antiferromagnetic insulator triggered by ultrafast spin–phonon interactions. Nat. Commun. 14, 1818 (2023).Article Google Scholar Zhang, Z. et al. Terahertz field-induced nonlinear coupling of two magnon modes in an antiferromagnet. Nat. Phys. 20, 801–806 (2024).Article Google Scholar Huang, C. et al. Extreme terahertz magnon multiplication induced by resonant magnetic pulse pairs. Nat. Commun. 15, 3214 (2024).Article ADS Google Scholar Makihara, T. et al. Ultrastrong magnon–magnon coupling dominated by antiresonant interactions. Nat. Commun. 12, 3115 (2021).Article ADS Google Scholar Li, X. et al. Observation of Dicke cooperativity in magnetic interactions. Science 361, 794–797 (2018).Article ADS MathSciNet Google Scholar Krawczyk, M. & Grundler, D. Review and prospects of magnonic crystals and devices with reprogrammable band structure. J. Phys. Condens. Matter 26, 123202 (2014).Article ADS Google Scholar Chumak, A. V., Vasyuchka, V. I., Serga, A. A. & Hillebrands, B. Magnon spintronics. Nat. Phys. 11, 453–461 (2015).Article Google Scholar Hubbard, J. Electron correlations in narrow energy bands. Proc. R. Soc. A 276, 238–257 (1963).ADS Google Scholar Chaudhary, S., Hsieh, D. & Refael, G. Orbital Floquet engineering of exchange interactions in magnetic materials. Phys. Rev. B 100, 220403 (2019).Article ADS Google Scholar Liu, J., Hejazi, K. & Balents, L. Floquet engineering of multiorbital Mott insulators: applications to orthorhombic titanates. Phys. Rev. Lett. 121, 107201 (2018).Article ADS Google Scholar Mentink, J. H. & Eckstein, M. Ultrafast quenching of the exchange interaction in a Mott insulator. Phys. Rev. Lett. 113, 057201 (2014).Article ADS Google Scholar Mentink, J. H. Manipulating magnetism by ultrafast control of the exchange interaction. J. Phys. Condens. Matter 29, 453001 (2017).Article ADS Google Scholar Mikhaylovskiy, R. V. et al. Ultrafast optical modification of exchange interactions in iron oxides. Nat. Commun. 6, 8190 (2015).Article ADS Google Scholar Mentink, J. H., Balzer, K. & Eckstein, M. Ultrafast and reversible control of the exchange interaction in Mott insulators. Nat. Commun. 6, 6708 (2015).Article ADS Google Scholar Batignani, G. et al. Probing ultrafast photo-induced dynamics of the exchange energy in a Heisenberg antiferromagnet. Nat. Photon. 9, 506–510 (2015).Article ADS Google Scholar Murakami, Y., Golež, D., Eckstein, M. & Werner, P. Photoinduced nonequilibrium states in Mott insulators. Rev. Mod. Phys. 97, 035001 (2025).Article ADS MathSciNet Google Scholar Eckstein, M. & Werner, P. Thermalization of a pump-excited Mott insulator. Phys. Rev. B 84, 035122 (2011).Article ADS Google Scholar Murakami, Y. et al. Charge, and η-spin separation in one-dimensional photodoped Mott insulators. Phys. Rev. Lett. 130, 106501 (2023).Article ADS Google Scholar Eckstein, M., Kollar, M. & Werner, P. Thermalization after an interaction quench in the Hubbard model. Phys. Rev. Lett. 103, 056403 (2009).Article ADS Google Scholar Ehrke, H. et al. Photoinduced melting of antiferromagnetic order in La0.5Sr1.5MnO4 measured using ultrafast resonant soft X-ray diffraction. Phys. Rev. Lett. 106, 217401 (2011).Article ADS Google Scholar Afanasiev, D. et al. Ultrafast spin dynamics in photodoped spin–orbit Mott insulator Sr2IrO4. Phys. Rev. X 9, 021020 (2019).

Google Scholar Caviglia, A. D. et al. Photoinduced melting of magnetic order in the correlated electron insulator NdNiO3. Phys. Rev. B 88, 220401 (2013).Article ADS Google Scholar Först, M. et al. Spatially resolved ultrafast magnetic dynamics initiated at a complex oxide heterointerface. Nat. Mater. 14, 883–888 (2015).Article ADS Google Scholar Ishihara, S. Photoinduced ultrafast phenomena in correlated electron magnets. J. Phys. Soc. Jpn. 88, 072001 (2019).Article ADS Google Scholar Eremenko, V. V. & Kharchenko, N. F. Magneto-optics of antiferromagnets. Phys. Rep. 155, 379–401 (1987).Article ADS Google Scholar Kimel, A. V. et al. Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses. Nature 435, 655–657 (2005).Article ADS Google Scholar Adams, D. J. & Amadon, B. Study of the volume and spin collapse in orthoferrite LuFeO3 using LDA+U. Phys. Rev. B 79, 115114 (2009).Article ADS Google Scholar Stoeffler, D. & Chaker, Z. First principles study of the electronic structure and magnetic properties of YFeO3 oxide. J. Magn. Magn. Mater. 442, 255–264 (2017).Article ADS Google Scholar Zvezdin, A. K. & Matveev, V. M. Theory of the magnetic properties of dysprosium orthoferrite. Sov. Phys. J. 50, 543–548 (1979).ADS Google Scholar Balbashov, A., Volkov, A., Lebedev, S., Mukhin, A. & Prokhorov, A. High-frequency magnetic properties of dysprosium orthoferrite. Zh. Eksp. Teor. Fiz. 88, 974–987 (1985).

Google Scholar Li, X., Kim, D., Liu, Y. & Kono, J. Terahertz spin dynamics in rare-earth orthoferrites. Photon. Insights 1, R05 (2023).Article Google Scholar Khomskii, D. I.

Transition Metal Compounds (Cambridge Univ. Press, 2014).Wood, D. L., Remeika, J. P. & Kolb, E. D. Optical spectra of rare-earth orthoferrites. J. Appl. Phys. 41, 5315–5322 (1970).Article ADS Google Scholar Yang, D. et al. Spin-orbit torque manipulation of sub-terahertz magnons in antiferromagnetic α-Fe2O3. Nat. Commun. 15, 4046 (2024).Article ADS Google Scholar Leenders, R. A., Afanasiev, D., Kimel, A. V. & Mikhaylovskiy, R. V. Canted spin order as a platform for ultrafast conversion of magnons. Nature 630, 335–339 (2024).Article ADS Google Scholar Kalashnikova, A. M. Impulsive generation of coherent magnons by linearly polarized light in the easy-plane antiferromagnet FeBO3. Phys. Rev. Lett. 99, 167205 (2007).Article ADS Google Scholar Afanasiev, D. et al. Control of the ultrafast photoinduced magnetization across the Morin transition in DyFeO3. Phys. Rev. Lett. 116, 097401 (2016).Article ADS Google Scholar Leenders, R. A. & Mikhaylovskiy, R. V. Theory of optical generation and detection of propagating magnons in an antiferromagnet. Phys. Rev. B 107, 094423 (2023).Article ADS Google Scholar Dean, M. P. M. et al. Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4. Nat. Mater. 15, 601–605 (2016).Article ADS Google Scholar Schönfeld, C. et al. Dynamical renormalization of the magnetic excitation spectrum via high-momentum nonlinear magnonics. Sci. Adv. 11, eadv4207 (2025).Article ADS Google Scholar Imada, M., Fujimori, A. & Tokura, Y. Metal-insulator transitions. Rev. Mod. Phys. 70, 1039–1263 (1998).Article ADS Google Scholar Träger, N. et al. Real-space observation of magnon interaction with driven space-time crystals. Phys. Rev. Lett. 126, 057201 (2021).Article ADS Google Scholar Troncoso, R. E., Ulloa, C., Pesce, F. & Nunez, A. S. Antiferromagnetic magnonic crystals. Phys. Rev. B 92, 224424 (2015).Article ADS Google Scholar Streib, S., Vidal-Silva, N., Shen, K. & Bauer, G. E. W. Magnon–phonon interactions in magnetic insulators. Phys. Rev. B 99, 184442 (2019).Article ADS Google Scholar Radovskaia, V. et al. Figure source data for ‘Photoengineering the magnon spectrum in insulating antiferromagnet’. Zenodo https://doi.org/10.5281/zenodo.18430301 (2026).Download referencesWe thank K. Saeedi Ilkhchy and C. Berkhout for their technical support, as well as J. Mentink for fruitful discussions. This work is supported by ERC grant 852050 MAGSHAKE (to R.V.M.); ERC grant 101078206 ASTRAL (to D.A.); programme ‘Materials for the Quantum Age’ (QuMat, registration number 024.005.006 to A.V.K. and D.A.), which is part of the Gravitation programme financed by the Dutch Ministry of Education, Culture and Science (OCW); and the European Research Council ERC grant agreement no. 101054664 273 (SPARTACUS to A.V.K.). R.C. received support by Horizon Europe EIC Pathfinder under the grant IQARO number 101115190 and from the Italian PNRR MUR project PE0000023-NQSTI. R.A. and E.D. acknowledge the SNSF project 200021_212899, NCCR SPIN, a National Centre of Competence in Research, funded by the Swiss National Science Foundation (grant no. 225153), and the Swiss State Secretariat for Education, Research and Innovation contract no. UeM019-1). The work was partly was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract no. MB22.00071 (to A.D.C.), the Gordon and Betty Moore Foundation (grant no. 332 GBMF10451 to A.D.C.), the European Research Council (ERC) (grant no. 677458), by the project Quantox of QuantERA ERA-NET Cofund in Quantum Technologies, and by the Netherlands Organisation for Scientific Research (NWO/OCW) as part of the VIDI (project 016.Vidi.189.061 to A.D.C.), the ENW-GROOT (project TOPCORE) programme (to A.D.C.)Institute for Molecules and Materials, Radboud University, Nijmegen, the NetherlandsV. Radovskaia, M. X. Na, B. A. Ivanov, A. V. Kimel & D. AfanasievInstitute for Theoretical Physics, ETH Zurich, Zurich, SwitzerlandR. Andrei, S. Chattopadhyay & E. DemlerKavli Institute of Nanoscience, Delft University of Technology, Delft, the NetherlandsJ. R. HortensiusElectromagnetic Signatures and Propagation, TNO, The Hague, the NetherlandsJ. R. HortensiusDepartment of Physics, Lancaster University, Lancaster, UKR. V. MikhaylovskiyDipartimento di Fisica ‘E. R. Caianiello’, Università degli Studi di Salerno, CNR-SPIN, Fisciano, ItalyR. CitroLyman Laboratory, Department of Physics, Harvard University, Cambridge, MA, USAS. ChattopadhyayInstitute of Magnetism, National Academy of Sciences of Ukraine, Kyiv, UkraineB. A. IvanovDepartment of Quantum Matter Physics, University of Geneva, Geneva, SwitzerlandA. D. CavigliaSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarD.A. and A.D.C. conceived the project. D.A., A.V.K. and A.D.C. supervised the study. V.R., J.R.H., M.X.N. and D.A. performed the experiments. R.A. and E.D. provided the theoretical model. B.A.I., R.V.M., S.C. and R.C. contributed to the theoretical treatment of the experimental results. D.A., V.R. and R.A. wrote the original draft with feedback from all the co-authors.Correspondence to V. Radovskaia or D. Afanasiev.The authors declare no competing interests.Nature Physics thanks Romain Lebrun, Alexej Pashkin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.The time-resolved signals (illustrated schematically at the top-left and top-right) were obtained using a pump-probe technique. The first, pump pulse (purple) excites the near-surface region (depicted as the blue area with exponential profile), and the second, probe pulse with wavevector kpr (orange, bottom-left) measures the magnetic response. When transmitted through the medium, the probe pulse experiences a magneto-optical Faraday rotation θF of its polarization due to the net magnetization M(t) (shown enlarged in the inset), thus providing information about localized magnon dynamics with k ≈ 0 (middle-right; purple colour). The refracted portion of the probe pulse acquires a new wavevector k*pr within the sample, and is subsequently reflected by inhomogeneities possessing a spatial periodicity matching – specifically, magnons with the wavevector k0 = 2k*pr (schematically shown as red ‘waves’). The polarization rotation of this reflected portion is the magneto-optical Kerr rotation θK, which provides insights into propagating magnons with wavevector k0 (top-left; red color).Time-traces for the k ≈ 0 dynamics excited by linearly-polarized pump with different orientation of polarization when pumping (a) not in CT-regime and (b) in CT-regime. On the panel (a) the scatters are experimental data points and solid lines are sinusoidal fits. On panel (b) solid lines are the experimental time-traces. Labels from 00 to 1800 denote the orientation of the pump polarization for every particular curve. Top-left insets on both graphs show the spatial distribution of the excitation. Top-right insets are the dependences of the amplitude from the angle of the pump polarization. While in CT-regime (b) the magnetic dynamics is isotropic, in off-resonant regime (a) the orientation of pump polarization allows to control not only the amplitude of the dynamics, but also the phase (compare ‘+’ light-blue and ‘-‘ dark-green curves).Source data(a) Fourier spectra of the unperturbed equilibrium (orange color) and CT-excitation-modulated part (purple) part of the localized k ≈ 0 magnon mode for different temperatures (T = 50, 53, 56 K). Black solid lines are the fits taken as a sum of asymmetrical gaussian (purple filled peaks) and symmetrical gaussian (orange filled peaks) at frequencies fp and f0, respectively. (b) The frequencies f0 and fp plotted as a function of temperature. Inset is a zoom-in of range from 45 K to 100 K. Orange-edge circles and purple-edge squares are experimental data points for hv < ECT and hv < ECT, respectively. Black solid line is the adaptation from39. Yellow shadow area with orange arrow represents the heating in the local excited area by above CT-bandgap laser pulse with pump fluence 1 mJ/cm2.Source data(a) Time-resolved trace of the MO Kerr rotation θK probing the coherent dynamics excited by the above-bandgap pump excitation (hv = 3.1 eV). The parameters were set to: λpr = 515 nm (k0 = 0.94*105 cm−1) T ≈ 60 K. (b) (left panel) Fourier spectrum and (right panel) the wavelet analysis of the signal from (a). Three main states can be distinguished: k0 phonon peak ( ≈ 0.06 THz), k0 magnon peak ( ≈ 0.25 THz) and the in-gap state originating from the early-time distortion ( ≈ 0.1 THz). (c) Temperature-dependence for the frequency of the equilibrium k ≈ 0 magnons f0, in-gap state fp and acoustic phonon at k0 = 0.68*105 cm−1 (λpr = 670 nm).Source data(a) Time-resolved traces of the magneto-optical Kerr rotation (MOKE) θk excited by pumping with different pump photon energies hv from 2.9 eV up to 3.5 eV. The bold part of the curves, as well as purple shaded area, highlights the distorted early-time magnon dynamics with a duration of τ. Top right inset shows a spatial distribution of the probed magnon dynamics; δ is a pump penetration depth. (b) τ (left axis, circles) and δ (right axis, solid line) as a function of pump photon energy hv. Here τ was determined by visual inspection of the start-time of coherent oscillations from (a).Source data(a) Time-traces of k = k0 magnon mode for different fluences of the above-bandgap pump excitation (hv = 3.1 eV). The inset schematically shows spatial localization of the measured dynamics; δ is the pump penetration depth; Vk is the group velocity of the propagating magnon. Purple shady area, as well as purple color of curves, highlights early-time τ distorted dynamics. (b) (circles) Experimental values of the decay rate of CT-driven k = k0 magnon mode, γk, as a function of pump fluence. Red solid line is guide-to-eye. Error bars indicate 1σ uncertainties from nonlinear least-squares fitting. (inset) Fourier peak of late-time coherent part of k = k0 mode for different pump fluences. Neither the central frequency of the peak fk ≈ 0.25 THz (highlighted by shady red stripe), nor the FWHM bandwidth ΔfFWHM ≈ 0.01 THz are affected by the pump-fluence.Source dataTime-resolved dynamics of the transient reflectivity following the ultrafast CT excitation. Circles represent experimental data points, and the red line shows a three-exponential fit with relaxation times: \({\tau }_{0} \approx 1\) ps, \({\tau }_{1} \approx 20\) ps and \({\tau }_{2} \approx 1\) ns. The last two time constants suggest that the non-equilibrium behavior of the photoexcited carriers extends far beyond the ≈7 ps lifetime of the spin precession. The central inset is a schematic representation of the CT electronic excitation. The top-right inset is the fluence-dependence of the amplitude A1 of the \({\tau }_{1}\) exponent. Open circles are the experimental values, and the straight solid line is a linear fit.Source dataSupplementary Notes S1-S5, Supplementary Figures S1-S16.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Data points for plots.Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsRadovskaia, V., Andrei, R., Hortensius, J.R. et al. Photoengineering the magnon spectrum in an insulating antiferromagnet. Nat. Phys. (2026). https://doi.org/10.1038/s41567-026-03230-6Download citationReceived: 01 May 2025Accepted: 25 February 2026Published: 14 April 2026Version of record: 14 April 2026DOI: https://doi.org/10.1038/s41567-026-03230-6Anyone you share the following link with will be able to read this content:Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative