Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Rydberg exciton–polaritons in a Cu2O microcavity

Abstract

Giant Rydberg excitons with principal quantum numbers as high as n = 25 have been observed in cuprous oxide (Cu2O), a semiconductor in which the exciton diameter can become as large as 1 μm. The giant dimension of these excitons results in excitonic interaction enhancements of orders of magnitude. Rydberg exciton–polaritons, formed by the strong coupling of Rydberg excitons to cavity photons, are a promising route to exploit these interactions and achieve a scalable, strongly correlated solid-state platform. However, the strong coupling of these excitons to cavity photons has remained elusive. Here, by embedding a thin Cu2O crystal into a Fabry–Pérot microcavity, we achieve strong coupling of light to Cu2O Rydberg excitons up to n = 6 and demonstrate the formation of Cu2O Rydberg exciton–polaritons. These results pave the way towards realizing strongly interacting exciton–polaritons and exploring strongly correlated phases of matter using light on a chip.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Absorption spectrum and cavity structure.
Fig. 2: Momentum–space spectra.
Fig. 3: Real-space spectra.
Fig. 4: Zero-detuning line profiles and the effective coupling strength.
Fig. 5: Scaling of coupling strength.

Data availability

The research data underpinning this publication can be accessed from University of St Andrews Research Data repository at https://doi.org/10.17630/4f4e4d92-8309-45db-bade-26b147696138.

References

  1. Weisbuch, C., Nishioka, M., Ishikawa, A. & Arakawa, Y. Observation of the coupled exciton–photon mode splitting in a semiconductor quantum microcavity. Phys. Rev. Lett. 69, 3314–3317 (1992).

    Article  CAS  Google Scholar 

  2. Lidzey, D. G. et al. Strong exciton–photon coupling in an organic semiconductor microcavity. Nature 395, 53–55 (1998).

    Article  CAS  Google Scholar 

  3. Dufferwiel, S. et al. Exciton–polaritons in van der Waals heterostructures embedded in tunable microcavities. Nat. Commun. 6, 8579 (2015).

    Article  CAS  Google Scholar 

  4. Fieramosca, A. et al. Two-dimensional hybrid perovskites sustaining strong polariton interactions at room temperature. Sci. Adv. 5, eaav9967 (2019).

    Article  CAS  Google Scholar 

  5. Carusotto, I. & Ciuti, C. Quantum fluids of light. Rev. Mod. Phys. 85, 299–366 (2013).

    Article  Google Scholar 

  6. Kasprzak, J. et al. Bose–Einstein condensation of exciton polaritons. Nature 443, 409 (2006).

    Article  CAS  Google Scholar 

  7. Plumhof, J. D., Stöferle, T., Mai, L., Scherf, U. & Mahrt, R. F. Room-temperature Bose–Einstein condensation of cavity exciton–polaritons in a polymer. Nat. Mater. 13, 247–252 (2014).

    Article  CAS  Google Scholar 

  8. Su, R. et al. Observation of exciton polariton condensation in a perovskite lattice at room temperature. Nat. Phys. 16, 301–306 (2020).

    Article  CAS  Google Scholar 

  9. Klembt, S. et al. Exciton–polariton topological insulator. Nature 562, 552–556 (2018).

    Article  CAS  Google Scholar 

  10. Amo, A. & Bloch, J. Exciton–polaritons in lattices: a non-linear photonic simulator. C. R. Phys. 17, 934–945 (2016).

    Article  CAS  Google Scholar 

  11. Sanvitto, D. & Kéna-Cohen, S. The road towards polaritonic devices. Nat. Mater. 15, 1061 (2016).

    Article  CAS  Google Scholar 

  12. Ballarini, D. et al. All-optical polariton transistor. Nat. Commun. 4, 1778 (2013).

    Article  CAS  Google Scholar 

  13. Zasedatelev, A. V. et al. A room-temperature organic polariton transistor. Nat. Photonics 13, 378–383 (2019).

  14. Boulier, T. et al. Polariton-generated intensity squeezing in semiconductor micropillars. Nat. Commun. 5, 3260 (2014).

    Article  CAS  Google Scholar 

  15. Cuevas, A. et al. First observation of the quantized exciton–polariton field and effect of interactions on a single polariton. Sci. Adv. https://www.science.org/doi/10.1126/sciadv.aao6814 (2018).

  16. Muñoz-Matutano, G. et al. Emergence of quantum correlations from interacting fibre-cavity polaritons. Nat. Mater. 18, 213–218 (2019).

    Article  CAS  Google Scholar 

  17. Delteil, A. et al. Towards polariton blockade of confined exciton–polaritons. Nat. Mater. 18, 219–222 (2019).

    Article  CAS  Google Scholar 

  18. Kazimierczuk, T., Fröhlich, D., Scheel, S., Stolz, H. & Bayer, M. Giant Rydberg excitons in the copper oxide Cu2O. Nature 514, 343–347 (2014).

    Article  CAS  Google Scholar 

  19. Heckötter, J. et al. Asymmetric Rydberg blockade of giant excitons in cuprous oxide. Nat. Commun. 12, 3556 (2021).

    Article  CAS  Google Scholar 

  20. Versteegh, M. A. M. et al. Giant Rydberg excitons in Cu2O probed by photoluminescence excitation spectroscopy. Phys. Rev. B 104, 245206 (2021).

    Article  CAS  Google Scholar 

  21. Thewes, J. et al. Observation of high angular momentum excitons in cuprous oxide. Phys. Rev. Lett. 115, 027402 (2015).

    Article  CAS  Google Scholar 

  22. Heckötter, J. et al. High-resolution study of the yellow excitons in Cu2O subject to an electric field. Phys. Rev. B 95, 035210 (2017).

    Article  Google Scholar 

  23. Schweiner, F., Main, J., Feldmaier, M., Wunner, G. & Uihlein, C. Impact of the valence band structure of Cu2O on excitonic spectra. Phys. Rev. B 93, 195203 (2016).

    Article  CAS  Google Scholar 

  24. Kitamura, T., Takahata, M. & Naka, N. Quantum number dependence of the photoluminescence broadening of excitonic Rydberg states in cuprous oxide. J. Lumin. 192, 808–813 (2017).

    Article  CAS  Google Scholar 

  25. Saffman, M., Walker, T. G. & Mølmer, K. Quantum information with Rydberg atoms. Rev. Mod. Phys. 82, 2313–2363 (2010).

    Article  CAS  Google Scholar 

  26. Weimer, H., Müller, M., Lesanovsky, I., Zoller, P. & Büchler, H. P. A Rydberg quantum simulator. Nat. Phys. 6, 382–388 (2010).

    Article  CAS  Google Scholar 

  27. Semina, M. A. Fine structure of Rydberg excitons in cuprous oxide. Phys. Solid State 60, 1527–1536 (2018).

    Article  CAS  Google Scholar 

  28. Aßmann, M. & Bayer, M. Semiconductor Rydberg physics. Adv. Quantum Technol. 3, 1900134 (2020).

    Article  CAS  Google Scholar 

  29. Hartmann, M. J. Quantum simulation with interacting photons. J. Opt. 18, 104005 (2016).

    Article  Google Scholar 

  30. Chang, D. E., Vuletić, V. & Lukin, M. D. Quantum nonlinear optics—photon by photon. Nat. Photonics 8, 685–694 (2014).

    Article  CAS  Google Scholar 

  31. Saffman, M., Walker, T. G. & Mølmer, K. Quantum information with Rydberg atoms. Rev. Mod. Phys. 82, 2313–2363 (2010).

    Article  CAS  Google Scholar 

  32. Browaeys, A. & Lahaye, T. Many-body physics with individually controlled Rydberg atoms. Nat. Phys. 16, 132–142 (2020).

    Article  CAS  Google Scholar 

  33. Schöne, F., Stolz, H. & Naka, N. Phonon-assisted absorption of excitons in Cu2O. Phys. Rev. B 96, 115207 (2017).

    Article  Google Scholar 

  34. Toyozawa, Y. Interband effect of lattice vibrations in the exciton absorption spectra. J. Phys. Chem. Solids 25, 59–71 (1964).

    Article  CAS  Google Scholar 

  35. Kavokin, A. V., Baumberg, J. J., Malpuech, G. & Laussy, F. P. Microcavities (Oxford Univ. Press, 2017).

  36. Heckötter, J. et al. Rydberg excitons in the presence of an ultralow-density electron–hole plasma. Phys. Rev. Lett. 121, 097401 (2018).

    Article  Google Scholar 

  37. Gu, J. et al. Enhanced nonlinear interaction of polaritons via excitonic Rydberg states in monolayer WSe2. Nat. Commun. 12, 2269 (2021).

    Article  CAS  Google Scholar 

  38. Bao, W. et al. Observation of Rydberg exciton polaritons and their condensate in a perovskite cavity. Proc. Natl Acad. Sci. USA 116, 20274–20279 (2019).

    Article  CAS  Google Scholar 

  39. Walther, V., Grünwald, P. & Pohl, T. Controlling exciton–phonon interactions via electromagnetically induced transparency. Phys. Rev. Lett. 125, 173601 (2020).

    Article  CAS  Google Scholar 

  40. Walther, V., Johne, R. & Pohl, T. Giant optical nonlinearities from Rydberg excitons in semiconductor microcavities. Nat. Commun. 9, 1309 (2018).

    Article  CAS  Google Scholar 

  41. Walther, V., Krüger, S. O., Scheel, S. & Pohl, T. Interactions between Rydberg excitons in Cu2O. Phys. Rev. B 98, 165201 (2018).

    Article  CAS  Google Scholar 

  42. Delteil, A. et al. Towards polariton blockade of confined exciton–polaritons. Nat. Mater. 18, 219–222 (2019).

    Article  CAS  Google Scholar 

  43. Gorshkov, A. V., Otterbach, J., Fleischhauer, M., Pohl, T. & Lukin, M. D. Photon–photon interactions via Rydberg blockade. Phys. Rev. Lett. 107, 133602 (2011).

    Article  CAS  Google Scholar 

  44. Lynch, S. A. et al. Rydberg excitons in synthetic cuprous oxide Cu2O. Phys. Rev. Mater. 5, 084602 (2021).

    Article  CAS  Google Scholar 

  45. Steinhauer, S. et al. Rydberg excitons in Cu2O microcrystals grown on a silicon platform. Commun. Mater. 1, 1–7 (2020).

    Article  Google Scholar 

  46. Konzelmann, A., Frank, B. & Giessen, H. Quantum confined Rydberg excitons in reduced dimensions. J. Phys. B 53, 024001 (2019).

    Article  CAS  Google Scholar 

  47. Ziemkiewicz, D., Karpiński, K., Czajkowski, G. & Zielińska-Raczyńska, S. Excitons in Cu2O: from quantum dots to bulk crystals and additional boundary conditions for Rydberg exciton–polaritons. Phys. Rev. B 101, 205202 (2020).

    Article  CAS  Google Scholar 

  48. Orfanakis, K. et al. Quantum confined Rydberg excitons in Cu2O nanoparticles. Phys. Rev. B 103, 245426 (2021).

    Article  CAS  Google Scholar 

  49. Jacqmin, T. et al. Direct observation of Dirac cones and a flatband in a honeycomb lattice for polaritons. Phys. Rev. Lett. 112, 116402 (2014).

    Article  CAS  Google Scholar 

  50. Ohadi, H. et al. Synchronization crossover of polariton condensates in weakly disordered lattices. Phys. Rev. B 97, 195109 (2018).

    Article  CAS  Google Scholar 

  51. Fano, U. Effects of configuration interaction on intensities and phase shifts. Phys. Rev. 124, 1866–1878 (1961).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the EPSRC through grant number EP/S014403/1, by the Royal Society through RGS\R2\192174, by the Carlsberg Foundation through the ‘Semper Ardens’ Research Project QCooL, by the NSF through a grant for ITAMP at Harvard University, by the DFG through SPP1929, and by the Danish National Research Foundation through the Center of Excellence ‘CCQ’ (grant agreement number DNRF156). K.O. acknowledges the EPSRC for PhD studentship support through grant number EP/L015110/1. S.K.R. acknowledges the Carnegie Trust for the Universities of Scotland Research Incentive Grant RIG009823. T.V. acknowledges support through the Australian Research Council Centre of Excellence for Engineered Quantum Systems (CE170100009). V.W. acknowledges support by the NSF through a grant for the Institute for Theoretical Atomic, Molecular, and Optical Physics at Harvard University and the Smithsonian Astrophysical Observatory. We thank J. Keeling for fruitful discussions. We also thank Y. Nanao and EPSRC grant number EP/T023449/1 for the X-ray diffraction measurements.

Author information

Authors and Affiliations

Authors

Contributions

K.O. polished the sample, performed spectroscopy and analysed the data. S.K.R. deposited DBRs and performed the transfer matrix simulations. V.W. and T.P. developed the theory. T.V. and H.O. supervised the project. H.O. conceived and designed the project. All authors contributed to the writing of the manuscript.

Corresponding author

Correspondence to Hamid Ohadi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Materials thanks Na Young Kim and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–14, Tables 1 and 2, and discussion sections 1–8.

Reporting Summary

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Orfanakis, K., Rajendran, S.K., Walther, V. et al. Rydberg exciton–polaritons in a Cu2O microcavity. Nat. Mater. 21, 767–772 (2022). https://doi.org/10.1038/s41563-022-01230-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41563-022-01230-4

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing