• Van Kranendonk, J. & Van Vleck, J. H. Spin waves. Rev. Mod. Phys. 30, 1 (1958).

    Article 

    Google Scholar
     

  • Chumak, A. V., Vasyuchka, V. I., Serga, A. A. & Hillebrands, B. Magnon spintronics. Nat. Phys. 11, 453–461 (2015).

    Article 
    CAS 

    Google Scholar
     

  • de Gennes, P. G. Collective motions of hydrogen bonds. Solid State Commun. 1, 132–137 (1963).

    Article 

    Google Scholar
     

  • Bauer, G. E. W., Iguchi, R. & Uchida, K. Theory of transport in ferroelectric capacitors. Phys. Rev. Lett. 126, 187603 (2021).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Tang, P., Iguchi, R., Uchida, K. & Bauer, G. E. W. Excitations of the ferroelectric order. Phys. Rev. B 106, L081105 (2022).

    Article 
    CAS 

    Google Scholar
     

  • Bauer, G. E. W. et al. Polarization transport in ferroelectrics. Phys. Rev. Appl. 20, 050501 (2023).

    Article 
    CAS 

    Google Scholar
     

  • Zhou, X.-H. et al. Surface ferron excitations in ferroelectrics and their directional routing. Chin. Phys. Lett. 40, 087103 (2023).

    Article 
    CAS 

    Google Scholar
     

  • Rodríguez-Suárez, R. L. et al. Surface and volume modes of polarization waves in ferroelectric films. Phys. Rev. B 109, 134307 (2024).

    Article 

    Google Scholar
     

  • Galiffi, E. et al. Extreme light confinement and control in low-symmetry phonon-polaritonic crystals. Nat. Rev. Mater. 9, 9–28 (2024).

    Article 

    Google Scholar
     

  • Wang, H. et al. Planar hyperbolic polaritons in 2D van der Waals materials. Nat. Commun. 15, 69 (2024).

    Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Abdelwahab, I. et al. Giant second-harmonic generation in ferroelectric NbOI2. Nat. Photonics 16, 644–650 (2022).

    Article 
    CAS 

    Google Scholar
     

  • Wu, Y. et al. Data-driven discovery of high performance layered van der Waals piezoelectric NbOI2. Nat. Commun. 13, 1884 (2022).

    Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Huang, C.-Y. et al. Coupling of electronic transition to ferroelectric order in a 2D semiconductor. Nat. Commun. 16, 1896 (2025).

    Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Yan, Y., Gamble, E. B. Jr & Nelson, K. A. Impulsive stimulated scattering: general importance in femtosecond laser pulse interactions with matter, and spectroscopic applications. J. Chem. Phys. 83, 5391–5399 (1985).

    Article 
    CAS 

    Google Scholar
     

  • Cheng, T. K. et al. Impulsive excitation of coherent phonons observed in reflection in bismuth and antimony. Appl. Phys. Lett. 57, 1004 (1990).

    Article 
    CAS 

    Google Scholar
     

  • Zeiger, H. J. et al. Theory for displacive excitation of coherent phonons. Phys. Rev. B 45, 768 (1992).

    Article 
    CAS 

    Google Scholar
     

  • Merlin, R. Generating coherent THz phonons with light pulses. Solid State Commun. 102, 207–220 (1997).

    Article 

    Google Scholar
     

  • Handa, T. et al. Terahertz emission from giant optical rectification in a van der Waals material. Nat. Mater. 24, 1203–1208 (2025).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Ma, W. et al. In-plane anisotropic and ultra-low-loss polaritons in a natural van der Waals crystal. Nature 562, 557–562 (2018).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • de Oliveira, T. V. A. G. et al. Nanoscale-confined terahertz polaritons in a van der Waals crystal. Adv. Mater. 33, 2005777 (2021).

    Article 
    PubMed 

    Google Scholar
     

  • F. Tresguerres-Mata, A. I. et al. Observation of naturally canalized phonon polaritons in LiV2O5 thin layers. Nat. Commun. 15, 2696 (2024).

    Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Terán-García, E. et al. Real-space visualization of canalized ray polaritons in a single van der Waals thin slab. Nano Lett. 25, 2203–2209 (2025).

    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Liu, L. et al. Long-range hyperbolic polaritons on a non-hyperbolic crystal surface. Nature 644, 76–82 (2025).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Delor, M., Weaver, H. L., Yu, Q. & Ginsberg, N. S. Imaging material functionality through three-dimensional nanoscale tracking of energy flow. Nat. Mater. 19, 56–62 (2020).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Bauer, G. E. W., Tang, P., Iguchi, R. & Uchida, K. Magnonics vs. ferronics. J. Magn. Magn. Mater. 541, 168468 (2022).

    Article 
    CAS 

    Google Scholar
     

  • Tang, P., Iguchi, R., Uchida, K. & Bauer, G. E. W. Thermoelectric polarization transport in ferroelectric ballistic point contacts. Phys. Rev. Lett. 128, 047601 (2022).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Sivasubramanian, S., Widom, A. & Srivastava, Y. N. Physical kinetics of ferroelectric hysteresis. Ferroelectrics 300, 43–55 (2004).

    Article 
    CAS 

    Google Scholar
     

  • Kuznetsov, A. V. & Stanton, C. J. Coherent phonon oscillations in GaAs. Phys. Rev. B 51, 7555 (1995).

    Article 
    CAS 

    Google Scholar
     

  • Dekorsy, T. et al. Emission of submillimeter electromagnetic waves by coherent phonons. Phys. Rev. Lett. 74, 738 (1995).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Dekorsy, T. et al. THz-wave emission by coherent optical phonons. Physica B 219, 775–777 (1996).

    Article 

    Google Scholar
     

  • Camley, R. E. Long-wavelength surface spin waves on antiferromagnets. Phys. Rev. Lett. 45, 283 (1980).

    Article 
    CAS 

    Google Scholar
     

  • Lüthi, B., Mills, D. L. & Camley, R. E. Surface spin waves in antiferromagnets. Phys. Rev. B 28, 1475 (1983).

    Article 

    Google Scholar
     

  • Damon, R. W. & Eshbach, J. R. Magnetostatic modes of a ferromagnet slab. J. Phys. Chem. Solids 19, 308–320 (1961).

    Article 

    Google Scholar
     

  • Walker, L. R. Magnetostatic modes in ferromagnetic resonance. Phys. Rev. 105, 390 (1957).

    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 
    CAS 

    Google Scholar
     

  • Feurer, T., Vaughan, J. C. & Nelson, K. A. Spatiotemporal coherent control of lattice vibrational waves. Science 299, 374–377 (2003).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Cavalleri, A. et al. Tracking the motion of charges in a terahertz light field by femtosecond X-ray diffraction. Nature 442, 664–666 (2006).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Prabhakar, A. & Stancil, D. D. Spin Waves: Theory and Applications Vol. 5 (Springer, 2009).

  • Awschalom, D. D. et al. Quantum engineering with hybrid magnonic systems and materials. IEEE Trans. Quantum Eng. 2, 1–36 (2021).

    Article 

    Google Scholar
     

  • Savitzky, B. H. et al. Image registration of low signal-to-noise cryo-STEM data. Ultramicroscopy 191, 56–65 (2018).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Handa, T. et al. Spontaneous exciton dissociation in transition metal dichalcogenide monolayers. Sci. Adv. 10, eadj4060 (2024).

    Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Tulyagankhodjaev, J. A. et al. Room-temperature wavelike exciton transport in a van der Waals superatomic semiconductor. Science 382, 438–442 (2023).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Baxter, J. M. et al. Coexistence of incoherent and ultrafast coherent exciton transport in a two-dimensional superatomic semiconductor. J. Phys. Chem. Lett. 14, 10249–10256 (2023).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Tang, P. & Bauer, G. E. W. Electric analog of magnons in order-disorder ferroelectrics. Phys. Rev. B 109, L060301 (2024).

    Article 
    CAS 

    Google Scholar
     

  • Zhuang, S. & Hu, J.-M. Role of polarization–photon coupling in ultrafast terahertz excitation of ferroelectrics. Phys. Rev. B 106, L140302 (2022).

    Article 
    CAS 

    Google Scholar
     

  • Jackson, J. D. Classical Electrodynamics (John Wiley & Sons, 2021).

  • Scrymgeour, D. A., Gopalan, V., Itagi, A., Saxena, A. & Swart, P. J. Phenomenological theory of a single domain wall in uniaxial trigonal ferroelectrics: lithium niobate and lithium tantalate. Phys. Rev. B 71, 184110 (2005).

    Article 

    Google Scholar
     

  • Phillpot, S. R. & Gopalan, V. Coupled displacive and order–disorder dynamics in LiNbO3 by molecular-dynamics simulation. Appl. Phys. Lett. 84, 1916–1918 (2004).

    Article 
    CAS 

    Google Scholar
     

  • Passler, N. C. & Paarmann, A. Generalized 4 × 4 matrix formalism for light propagation in anisotropic stratified media: study of surface phonon polaritons in polar dielectric heterostructures. J. Opt. Soc. Am. B 34, 2128–2139 (2017).

    Article 
    CAS 

    Google Scholar
     

  • Tayvah, U., Spies, J. A., Neu, J. & Schmuttenmaer, C. A. Nelly: a user-friendly and open-source implementation of tree-based complex refractive index analysis for terahertz spectroscopy. Anal. Chem. 93, 11243–11250 (2021).

    Article 
    CAS 
    PubMed 

    Google Scholar
     

  • Choe, J. et al. Observation of coherent ferron emission and propagation [source data]. figshare https://doi.org/10.6084/m9.figshare.31895293 (2026).