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).