Abstract
The discovery of ultraconfined polaritons with extreme anisotropy in a number of van der Waals (vdW) materials has unlocked new prospects for nanophotonic and optoelectronic applications. However, the range of suitable materials for specific applications remains limited. Here we introduce tellurite molybdenum quaternary oxides—which possess non-centrosymmetric crystal structures and extraordinary nonlinear optical properties—as a highly promising vdW family of materials for tunable low-loss anisotropic polaritonics. By employing chemical flux growth and exfoliation techniques, we successfully fabricate high-quality vdW layers of various compounds, including MgTeMoO6, ZnTeMoO6, MnTeMoO6 and CdTeMoO6. We show that these quaternary vdW oxides possess two distinct types of in-plane anisotropic polaritons: slab-confined and edge-confined modes. By leveraging metal cation substitutions, we establish a systematic strategy to finely tune the in-plane polariton propagation, resulting in the selective emergence of circular, elliptical or hyperbolic polariton dispersion, accompanied by ultraslow group velocities (0.0003c) and long lifetimes (5 ps). Moreover, Reststrahlen bands of these quaternary oxides naturally overlap that of α-MoO3, providing opportunities for integration. As an example, we demonstrate that combining α-MoO3 (an in-plane hyperbolic material) with CdTeMoO6 (an in-plane isotropic material) in a heterostructure facilitates collimated, diffractionless polariton propagation. Quaternary oxides expand the family of anisotropic vdW polaritons considerably, and with it, the range of nanophotonics applications that can be envisioned.
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References
Halasyamani, P. S. & Poeppelmeier, K. R. Noncentrosymmetric oxides. Chem. Mater. 10, 2753–2769 (1998).
Ok, K. M., Chi, E. O. & Halasyamani, P. S. Bulk characterization methods for non-centrosymmetric materials: second-harmonic generation, piezoelectricity, pyroelectricity, and ferroelectricity. Chem. Soc. Rev. 35, 710–717 (2006).
Zhao, S. et al. ZnTeMoO6: a strong second-harmonic generation material originating from three types of asymmetric building units. RSC Adv. 3, 14000–14006 (2013).
Ra, H.-S., Ok, K. M. & Halasyamani, P. S. Combining second-order Jahn–Teller distorted cations to create highly efficient SHG materials: synthesis, characterization, and NLO properties of BaTeM2O9 (M = Mo6+ or W6+). J. Am. Chem. Soc. 125, 7764–7765 (2003).
Zhang, J. et al. Top-seeded solution growth, morphology, and properties of a polar crystal Cs2TeMo3O12. Cryst. Growth Des. 11, 1863–1868 (2011).
Gao, Z., Tao, X., Yin, X., Zhang, W. & Jiang, M. Elastic, dielectric, and piezoelectric properties of BaTeMo2O9 single crystal. Appl. Phys. Lett. 93, 252906 (2008).
Wu, Q. et al. Biaxial crystal β-BaTeMo2O9: theoretical analysis and the feasibility as high-efficiency acousto-optic Q-switch. Opt. Express 25, 24893–24900 (2017).
Forzatti, P., Trifiro, F. & Villa, P. CdTeMoO6, CoTeMoO6, MnTeMoO6, and ZnTeMoO6: a new class of selective catalysts for allylic oxidation of butene and propylene. J. Catal. 55, 52–57 (1978).
Guo, X., Gao, Z. & Tao, X. Recent advances in tellurite molybdates/tungstates crystals. CrystEngComm 24, 7516–7529 (2022).
Xie, C., Yuan, H., Liu, Y. & Wang, X. Two-nodal surface phonons in solid-state materials. Phys. Rev. B 105, 054307 (2022).
Li, C. et al. Controlled growth of layered acentric CdTeMoO6 single crystals with linear and nonlinear optical properties. Cryst. Growth Des. 18, 3376–3384 (2018).
Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).
Basov, D., Fogler, M. & García de Abajo, F. Polaritons in van der Waals materials. Science 354, aag1992 (2016).
Low, T. et al. Polaritons in layered two-dimensional materials. Nat. Mater. 16, 182–194 (2017).
Ma, W. et al. In-plane anisotropic and ultra-low-loss polaritons in a natural van der Waals crystal. Nature 562, 557–562 (2018).
Zheng, Z. et al. A mid-infrared biaxial hyperbolic van der Waals crystal. Sci. Adv. 5, eaav8690 (2019).
Abedini Dereshgi, S. et al. Lithography-free IR polarization converters via orthogonal in-plane phonons in α-MoO3 flakes. Nat. Commun. 11, 5771 (2020).
Liu, Y., Chen, X. & Xu, Y. Topological phononics: from fundamental models to real materials. Adv. Funct. Mater. 30, 1904784 (2020).
Taboada-Gutiérrez, J. et al. Broad spectral tuning of ultra-low-loss polaritons in a van der Waals crystal by intercalation. Nat. Mater. 19, 964–968 (2020).
Zhang, X. et al. Ultrafast anisotropic dynamics of hyperbolic nanolight pulse propagation. Sci. Adv. 9, eadi4407 (2023).
Dai, S. et al. Tunable phonon polaritons in atomically thin van der Waals crystals of boron nitride. Science 343, 1125–1129 (2014).
Li, P. et al. Infrared hyperbolic metasurface based on nanostructured van der Waals materials. Science 359, 892–896 (2018).
Hu, G. et al. Topological polaritons and photonic magic angles in twisted α-MoO3 bilayers. Nature 582, 209–213 (2020).
Feres, F. H. et al. Sub-diffractional cavity modes of terahertz hyperbolic phonon polaritons in tin oxide. Nat. Commun. 12, 1995 (2021).
Ni, G. et al. Long-lived phonon polaritons in hyperbolic materials. Nano Lett. 21, 5767–5773 (2021).
Hu, H. et al. Doping-driven topological polaritons in graphene/α-MoO3 heterostructures. Nat. Nanotechnol. 17, 940–946 (2022).
Ma, W. et al. Ghost hyperbolic surface polaritons in bulk anisotropic crystals. Nature 596, 362–366 (2021).
Hu, C. et al. Source-configured symmetry-broken hyperbolic polaritons. eLight 3, 14 (2023).
Hu, G. et al. Real-space nanoimaging of hyperbolic shear polaritons in a monoclinic crystal. Nat. Nanotechnol. 18, 64–70 (2023).
Chaudhary, K. et al. Engineering phonon polaritons in van der Waals heterostructures to enhance in-plane optical anisotropy. Sci. Adv. 5, eaau7171 (2019).
Chen, S. et al. Real-space observation of ultraconfined in-plane anisotropic acoustic terahertz plasmon polaritons. Nat. Mater. 22, 860–866 (2023).
Qin, T., Ma, W., Wang, T. & Li, P. Phonon polaritons in van der Waals polar heterostructures for broadband strong light–matter interactions. Nanoscale 15, 12000–12007 (2023).
Chen, J. et al. Optical nano-imaging of gate-tunable graphene plasmons. Nature 487, 77–81 (2012).
Giles, A. J. et al. Ultralow-loss polaritons in isotopically pure boron nitride. Nat. Mater. 17, 134–139 (2018).
Li, P. et al. Optical nanoimaging of hyperbolic surface polaritons at the edges of van der Waals materials. Nano Lett. 17, 228–235 (2017).
Dai, S. et al. Manipulation and steering of hyperbolic surface polaritons in hexagonal boron nitride. Adv. Mater. 30, 1706358 (2018).
Caldwell, J. D. et al. Sub-diffractional volume-confined polaritons in the natural hyperbolic material hexagonal boron nitride. Nat. Commun. 5, 5221 (2014).
Li, P. et al. Hyperbolic phonon-polaritons in boron nitride for near-field optical imaging and focusing. Nat. Commun. 6, 7507 (2015).
Álvarez-Pérez, G., Voronin, K. V., Volkov, V. S., Alonso-González, P. & Nikitin, A. Y. Analytical approximations for the dispersion of electromagnetic modes in slabs of biaxial crystals. Phys. Rev. B 100, 235408 (2019).
Yang, X., Yao, J., Rho, J., Yin, X. & Zhang, X. Experimental realization of three-dimensional indefinite cavities at the nanoscale with anomalous scaling laws. Nat. Photon. 6, 450–454 (2012).
Yoxall, E. et al. Direct observation of ultraslow hyperbolic polariton propagation with negative phase velocity. Nat. Photon. 9, 674–678 (2015).
Jin, C. & Li, Z. Synthesis, crystal structure, optical property and theoretical studies of a noncentrosymmetric telluromolybdate CoTeMoO6. J. Alloy. Compd. 722, 381–386 (2017).
Mączka, M. et al. Growth and characterization of nonlinear optical telluromolybdate CoTeMoO6 single crystals. J. Solid State Chem. 220, 142–148 (2014).
Gupta, M., Rambadey, O. V. & Sagdeo, P. R. Probing the effect of R-cation radii on structural, vibrational, optical, and dielectric properties of rare earth (R = La, Pr, Nd) aluminates. Ceram. Int. 48, 23072–23080 (2022).
Yao, Z. et al. Probing subwavelength in-plane anisotropy with antenna-assisted infrared nano-spectroscopy. Nat. Commun. 12, 2649 (2021).
Huber, A., Ocelic, N., Kazantsev, D. & Hillenbrand, R. Near-field imaging of mid-infrared surface phonon polariton propagation. Appl. Phys. Lett. 87, 081103 (2005).
Zhao, Y. et al. Ultralow-loss phonon polaritons in the isotope-enriched α-MoO3. Nano Lett. 22, 10208–10215 (2022).
Chen, M. et al. Configurable phonon polaritons in twisted α-MoO3. Nat. Mater. 19, 1307–1311 (2020).
Duan, J. et al. Twisted nano-optics: manipulating light at the nanoscale with twisted phonon polaritonic slabs. Nano Lett. 20, 5323–5329 (2020).
Zheng, Z. et al. Phonon polaritons in twisted double-layers of hyperbolic van der Waals crystals. Nano Lett. 20, 5301–5308 (2020).
Duan, J. et al. Multiple and spectrally robust photonic magic angles in reconfigurable α-MoO3 trilayers. Nat. Mater. 22, 867–872 (2023).
Zhao, S. et al. A combination of multiple chromophores enhances second-harmonic generation in a nonpolar noncentrosymmetric oxide: CdTeMoO6. J. Mater. Chem. C 1, 2906–2912 (2013).
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).
Álvarez-Pérez, G. et al. Infrared permittivity of the biaxial van der Waals semiconductor α-MoO3 from near-and far-field correlative studies. Adv. Mater. 32, 1908176 (2020).
Acknowledgements
We acknowledge support from Z. Dai for Raman measurements and the efforts of Q. Ou and G. Si in exploring the material fabrication. P.L. acknowledges support from the National Natural Science Foundation of China (grant number 62075070) and the National Key Research and Development Program of China (grant number 2021YFA1201500), the Hubei Provincial Natural Science Foundation of China (grant number 2022CFA053) and the Innovation Fund of WNLO. S.Z. acknowledges support from the National Natural Science Foundation of China (grant numbers 22122507, 22193042, 21833010). R.C. acknowledges support from the China Postdoctoral Science Foundation (2021M701298).
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P.L. and S.Z. conceived the study. T.S. fabricated the samples and performed the s-SNOM measurements with the help of W.M. R.C. and T.S. carried out the fitting of the permittivity of the materials. H.W. synthesized the materials with the help of S.Z. T.S., R.C. and W.M. performed the simulations. T.S. and R.C. carried out the far-field experiments. Q.Y. performed the calculation of the phonon band structures. P.L., S.Z., X.Z. and J.L. coordinated and supervised the work. T.S. and P.L. wrote the paper with input from all co-authors. All authors read and approved the final paper.
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Sun, T., Chen, R., Ma, W. et al. Van der Waals quaternary oxides for tunable low-loss anisotropic polaritonics. Nat. Nanotechnol. (2024). https://doi.org/10.1038/s41565-024-01628-y
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DOI: https://doi.org/10.1038/s41565-024-01628-y
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