Abstract
Strong coupling between light and the fundamental excitations of a two-dimensional electron gas (2DEG) is of foundational importance both to pure physics and to the understanding and development of future photonic nanotechnologies1,2,3,4,5,6,7. Here we study the relationship between spin polarization of a 2DEG in a monolayer semiconductor, MoSe2, and light–matter interactions modified by a zero-dimensional optical microcavity. We find pronounced spin-susceptibility of the 2DEG to simultaneously enhance and suppress trion-polariton formation in opposite photon helicities. This leads to observation of a giant effective valley Zeeman splitting for trion-polaritons (g-factor of >20), exceeding the purely trionic splitting by over five times. Going further, we observe clear effective optical nonlinearity arising from the highly nonlinear behaviour of the valley-specific strong light–matter coupling regime, and allowing all-optical tuning of the polaritonic Zeeman splitting from 4 meV to >10 meV. Our experiments lay the groundwork for engineering topological phases with true unidirectionality in monolayer semiconductors, accompanied by giant effective photonic nonlinearities rooted in many-body exciton–electron correlations.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$209.00 per year
only $17.42 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
Data supporting the plots within this paper are available from the corresponding authors upon request.
References
Smolka, S. et al. Cavity quantum electrodynamics with many-body states of a two-dimensional electron gas. Science 346, 332–335 (2014).
Efimkin, D. K. & MacDonald, A. H. Many-body theory of trion absorption features in two-dimensional semiconductors. Phys. Rev. B 95, 035417 (2017).
Back, P. et al. Giant paramagnetism-induced valley polarization of electrons in charge-tunable monolayer MoSe2. Phys. Rev. Lett. 118, 237404 (2017).
Sidler, M. et al. Fermi polaron-polaritons in charge-tunable atomically thin semiconductors. Nat. Phys. 13, 255–261 (2017).
Tan, L. B. et al. Interacting polaron-polaritons. Phys. Rev. X 10, 021011 (2020).
Klein, J. et al. Controlling exciton many-body states by the electric-field effect in monolayer MoS2. Phys. Rev. Res. 3, L022009 (2021).
Roch, J. G. et al. Spin-polarized electrons in monolayer MoS2. Nat. Nanotechnol. 14, 432–436 (2019).
Glazov, M. M. Optical properties of charged excitons in two-dimensional semiconductors. J. Chem. Phys. 153, 034703 (2020).
Imamoglu, A., Cotlet, O. & Schmidt, R. Exciton-polarons in two-dimensional semiconductors and the Tavis-Cummings model. C. R. Phys. 22, 89–96 (2021).
MacNeill, D. et al. Breaking of valley degeneracy by magnetic field in monolayer MoSe2. Phys. Rev. Lett. 114, 037401 (2015).
Langer, F. et al. Lightwave valleytronics in a monolayer of tungsten diselenide. Nature 557, 76–80 (2018).
Ozawa, T. et al. Topological photonics. Rev. Mod. Phys. 91, 015006 (2019).
Li, M. et al. Experimental observation of topological Z2 exciton-polaritons in transition metal dichalcogenide monolayers. Nat. Commun. 12, 4425 (2021).
Liu, W. et al. Generation of helical topological exciton-polaritons. Science 370, 600–604 (2020).
Wang, Z., Chong, Y., Joannopoulos, J. D. & Soljačić, M. Observation of unidirectional backscattering-immune topological electromagnetic states. Nature 461, 772–775 (2009).
Lu, L., Joannopoulos, J. D. & Soljačić, M. Topological photonics. Nat. Photon. 8, 821–829 (2014).
Bahari, B. et al. Nonreciprocal lasing in topological cavities of arbitrary geometries. Science 358, 636–640 (2017).
Nalitov, A. V., Solnyshkov, D. D. & Malpuech, G. Polariton Z topological insulator. Phys. Rev. Lett. 114, 116401 (2015).
Klembt, S. et al. Exciton-polariton topological insulator. Nature 562, 552–556 (2018).
Song, W. et al. Breakup and recovery of topological zero modes in finite non-Hermitian optical lattices. Phys. Rev. Lett. 123, 165701 (2019).
Emmanuele, R. P. A. et al. Highly nonlinear trion-polaritons in a monolayer semiconductor. Nat. Commun. 11, 3589 (2020).
Keller, J. et al. Controlling the magneto-transport properties of EuS thin films. IEEE Trans. Magn. 38, 2673–2675 (2002).
Grzeszczyk, M. et al. The effect of metallic substrates on the optical properties of monolayer MoSe2. Sci. Rep. 10, 4981 (2020).
Roch, J. G. et al. First-order magnetic phase transition of mobile electrons in monolayer MoS2. Phys. Rev. Lett. 124, 187602 (2020).
Lyons, T. P. et al. Interplay between spin proximity effect and charge-dependent exciton dynamics in MoSe2/CrBr3 van der Waals heterostructures. Nat. Commun. 11, 6021 (2020).
Dufferwiel, S. et al. Valley-addressable polaritons in atomically thin semiconductors. Nat. Photon. 11, 497–501 (2017).
Lundt, N. et al. Magnetic-field-induced splitting and polarization of monolayer-based valley exciton polaritons. Phys. Rev. B 100, 121303(R) (2019).
Glazov, M. M. et al. Exciton fine structure and spin decoherence in monolayers of transition metal dichalcogenides. Phys. Rev. B 89, 201302(R) (2014).
Amo, A. et al. Exciton-polariton spin switches. Nat. Photon. 4, 361–366 (2010).
Smirnova, D., Leykam, D., Chong, Y. & Kivshar, Y. Nonlinear topological photonics. Appl. Phys. Rev. 7, 021306 (2020).
Acknowledgements
T.P.L. acknowledges financial support from the EPSRC Doctoral Prize Fellowship scheme (grant reference EP/R513313/1) and the JSPS Postdoctoral Fellowships for Research in Japan scheme. T.P.L., D.J.G., J.P., Y.O. and A.I.T. acknowledge support from the Royal Society International Exchange (grant no. IEC\R3\170088). T.P.L., D.J.G., A.G., C. Louca, L.K., I.A., M.B. and A.I.T. acknowledge support from an EPSRC Centre-to-Centre grant (no. EP/S030751/1). T.P.L., D.J.G. and A.I.T. additionally acknowledge financial support from the European Graphene Flagship Project (grant agreement no. 881603) and EPSRC (grants nos. EP/V006975/1, EP/P026850/1 and EP/V026496/1). C. Leblanc, D.S. and G.M. acknowledge support from projects EU ‘TOPOLIGHT’ (964770) and ‘QUANTOPOL’ (846353), from ANR Labex GaNEXT (ANR-11-LABX-0014) and the ANR programme ‘Investissements d’Avenir’ through the IDEX-ISITE initiative 16-IDEX-0001 (CAP 20-25). L.K., I.A. and M.B. acknowledge financial support from the Deutsche Forschungsgemeinschaft through the International Collaborative Research Centre 160 (project no. C2) and a UAR professorship, Mercur Foundation (grant no. Pe-2019-0022). We thank D. N. Krizhanovskii for useful discussions.
Author information
Authors and Affiliations
Contributions
T.P.L., D.J.G. and J.P. performed low-temperature magneto-optical spectroscopy. T.P.L., D.J.G., C. Leblanc, D.D.S., G.M. and A.I.T. analysed and discussed the bare flake and cavity spectroscopy data. C. Leblanc, D.D.S. and G.M. developed the cavity fitting model and rate equations. L.K. and I.A.A. collected and analysed time-resolved data. J.P. and P.M. deposited the EuS films onto DBR substrates. T.P.L., D.J.G., J.P. and P.M. performed SQUID magnetometry. C. Louca identified and transferred MoSe2 flakes onto EuS films. A.G. carried out electron density calculations. M.B., Y.O., G.M. and A.I.T. managed various aspects of the project. A.I.T. supervised the project. T.P.L. wrote the manuscript, with contributions from all co-authors.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Photonics thanks Anton Nalitov 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 Notes 1–5 and Figs. 1–8.
Rights and permissions
About this article
Cite this article
Lyons, T.P., Gillard, D.J., Leblanc, C. et al. Giant effective Zeeman splitting in a monolayer semiconductor realized by spin-selective strong light–matter coupling. Nat. Photon. 16, 632–636 (2022). https://doi.org/10.1038/s41566-022-01025-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41566-022-01025-8
This article is cited by
-
Energy transfer driven brightening of MoS2 by ultrafast polariton relaxation in microcavity MoS2/hBN/WS2 heterostructures
Nature Communications (2024)
-
Spin-selective strong light–matter coupling in a 2D hole gas-microcavity system
Nature Photonics (2023)
-
Negative-mass exciton polaritons induced by dissipative light-matter coupling in an atomically thin semiconductor
Nature Communications (2023)
-
Interspecies exciton interactions lead to enhanced nonlinearity of dipolar excitons and polaritons in MoS2 homobilayers
Nature Communications (2023)
-
Magneto-optical induced supermode switching in quantum fluids of light
Communications Physics (2023)