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Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe2/MoSe2 bilayers

Nature Nanotechnology volume 15, pages 750–754 (2020)Cite this article

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Abstract

Van der Waals heterostructures obtained via stacking and twisting have been used to create moiré superlattices1, enabling new optical and electronic properties in solid-state systems. Moiré lattices in twisted bilayers of transition metal dichalcogenides (TMDs) result in exciton trapping2,3,4,5, host Mott insulating and superconducting states6 and act as unique Hubbard systems7,8,9 whose correlated electronic states can be detected and manipulated optically. Structurally, these twisted heterostructures feature atomic reconstruction and domain formation10,11,12,13,14. However, due to the nanoscale size of moiré domains, the effects of atomic reconstruction on the electronic and excitonic properties have not been systematically investigated. Here we use near-0°-twist-angle MoSe2/MoSe2 bilayers with large rhombohedral AB/BA domains15 to directly probe the excitonic properties of individual domains with far-field optics. We show that this system features broken mirror/inversion symmetry, with the AB and BA domains supporting interlayer excitons with out-of-plane electric dipole moments in opposite directions. The dipole orientation of ground-state Γ–K interlayer excitons can be flipped with electric fields, while higher-energy K–K interlayer excitons undergo field-asymmetric hybridization with intralayer K–K excitons. Our study reveals the impact of crystal symmetry on TMD excitons and points to new avenues for realizing topologically non-trivial systems16,17, exotic metasurfaces18, collective excitonic phases19 and quantum emitter arrays20,21 via domain-pattern engineering.

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Fig. 1: AB/BA domains in t-MoSe2/MoSe2 devices.
Fig. 2: Electric-field-dependent PL spectra of the XI,1 peaks obtained from D2 at 4 K.
Fig. 3: Electric-field-dependent reflectance spectra of the X0 peaks obtained from D2 at 4 K.
Fig. 4: Electronic band structure of AB-stacked MoSe2/MoSe2.

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Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    Article  CAS  Google Scholar 

  2. Seyler, K. L. et al. Signatures of moiré-trapped valley excitons in MoSe2/WSe2 heterobilayers. Nature 567, 66–70 (2019).

    Article  CAS  Google Scholar 

  3. Tran, K. et al. Evidence for moiré excitons in van der Waals heterostructures. Nature 567, 71–75 (2019).

    Article  CAS  Google Scholar 

  4. Jin, C. et al. Observation of moiré excitons in WSe2/WS2 heterostructure superlattices. Nature 567, 76–80 (2019).

    Article  CAS  Google Scholar 

  5. Alexeev, E. M. et al. Resonantly hybridized excitons in moiré superlattices in van der Waals heterostructures. Nature 567, 81–86 (2019).

    Article  CAS  Google Scholar 

  6. Wang, L. et al. Correlated electronic phases in twisted bilayer transition metal dichalcogenides. Nat. Mater. https://doi.org/10.1038/s41563-020-0708-6 (2020).

  7. Tang, Y. et al. Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices. Nature 579, 353–358 (2020).

    Article  CAS  Google Scholar 

  8. Regan, E. C. et al. Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices. Nature 579, 359–363 (2020).

    Article  CAS  Google Scholar 

  9. Shimazaki, Y. et al. Strongly correlated electrons and hybrid excitons in a moiré heterostructure. Nature 580, 472–477 (2020).

    Article  CAS  Google Scholar 

  10. Enaldiev, V. V., Zólyomi, V., Yelgel, C., Magorrian, S. J. & Fal’ko, V. I. Stacking domains and dislocation networks in marginally twisted bilayers of transition metal dichalcogenides. Phys. Rev. Lett. 124, 206101 (2020).

    Article  CAS  Google Scholar 

  11. Weston, A. et al. Atomic reconstruction in twisted bilayers of transition metal dichalcogenides. Nat. Nanotechnol. https://doi.org/10.1038/s41565-020-0682-9 (2020).

  12. McGilly, L. J. et al. Visualization of moiré superlattices. Nat. Nanotechnol. https://doi.org/10.1038/s41565-020-0708-3 (2020).

  13. Sushko, A. et al. High resolution imaging of reconstructed domains and moire patterns in functional van der Waals heterostructure devices. Preprint at http://arxiv.org/abs/1912.07446 (2019).

  14. Rosenberger, M. R. et al. Twist angle-dependent atomic reconstruction and moiré patterns in transition metal dichalcogenide heterostructures. ACS Nano 14, 4550–4558 (2020).

    Article  CAS  Google Scholar 

  15. Toh, R. J., Sofer, Z., Luxa, J., Sedmidubský, D. & Pumera, M. 3R phase of MoS2 and WS2 outperforms the corresponding 2H phase for hydrogen evolution. Chem. Commun. 53, 3054–3057 (2017).

    Article  CAS  Google Scholar 

  16. Wu, F., Lovorn, T. & MacDonald, A. H. Topological exciton bands in moiré heterojunctions. Phys. Rev. Lett. 118, 147401 (2017).

    Article  Google Scholar 

  17. Perczel, J. et al. Topological quantum optics in two-dimensional atomic arrays. Phys. Rev. Lett. 119, 023603 (2017).

    Article  CAS  Google Scholar 

  18. Bekenstein, R. et al. Quantum metasurfaces with atom arrays. Nat. Phys. 16, 676–681 (2020).

    Article  CAS  Google Scholar 

  19. Byrnes, T., Recher, P. & Yamamoto, Y. Mott transitions of exciton polaritons and indirect excitons in a periodic potential. Phys. Rev. B 81, 205312 (2010).

    Article  Google Scholar 

  20. Yu, H., Liu, G.-B., Tang, J., Xu, X. & Yao, W. Moiré excitons: From programmable quantum emitter arrays to spin-orbit–coupled artificial lattices. Sci. Adv. 3, e1701696 (2017).

    Article  Google Scholar 

  21. Wu, F., Lovorn, T. & MacDonald, A. H. Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers. Phys. Rev. B 97, 035306 (2018).

    Article  CAS  Google Scholar 

  22. Yoo, H. et al. Atomic and electronic reconstruction at the van der Waals interface in twisted bilayer graphene. Nat. Mater. 18, 448–453 (2019).

    Article  CAS  Google Scholar 

  23. Woods, C. R. et al. Macroscopic self-reorientation of interacting two-dimensional crystals. Nat. Commun. 7, 10800 (2016).

    Article  CAS  Google Scholar 

  24. Wang, Z., Chiu, Y.-H., Honz, K., Mak, K. F. & Shan, J. Electrical tuning of interlayer exciton gases in WSe2 bilayers. Nano Lett. 18, 137–143 (2018).

    Article  CAS  Google Scholar 

  25. Jauregui, L. A. et al. Electrical control of interlayer exciton dynamics in atomically thin heterostructures. Science 366, 870–875 (2019).

    Article  CAS  Google Scholar 

  26. Scuri, G. et al. Large excitonic reflectivity of monolayer MoSe2 encapsulated in hexagonal boron nitride. Phys. Rev. Lett. 120, 037402 (2018).

    Article  CAS  Google Scholar 

  27. Zhou, Y. et al. Controlling excitons in an atomically thin membrane with a mirror. Phys. Rev. Lett. 124, 027401 (2020).

    Article  CAS  Google Scholar 

  28. Horng, J. et al. Observation of interlayer excitons in MoSe2 single crystals. Phys. Rev. B 97, 241404 (2018).

    Article  CAS  Google Scholar 

  29. Gerber, I. C. et al. Interlayer excitons in bilayer MoS2 with strong oscillator strength up to room temperature. Phys. Rev. B 99, 035443 (2019).

    Article  CAS  Google Scholar 

  30. Liu, K. et al. Evolution of interlayer coupling in twisted molybdenum disulfide bilayers. Nat. Commun. 5, 4966 (2014).

    Article  CAS  Google Scholar 

  31. Kunstmann, J. et al. Momentum-space indirect interlayer excitons in transition-metal dichalcogenide van der Waals heterostructures. Nat. Phys. 14, 801–805 (2018).

    Article  CAS  Google Scholar 

  32. Deilmann, T. & Thygesen, K. S. Interlayer excitons with large optical amplitudes in layered van der Waals materials. Nano Lett. 18, 2984–2989 (2018).

    Article  CAS  Google Scholar 

  33. Miller, B. et al. Long-lived direct and indirect interlayer excitons in van der Waals heterostructures. Nano Lett. 17, 5229–5237 (2017).

    Article  CAS  Google Scholar 

  34. Daniels, J. M., Machnikowski, P. & Kuhn, T. Excitons in quantum dot molecules: Coulomb coupling, spin-orbit effects, and phonon-induced line broadening. Phys. Rev. B 88, 205307 (2013).

    Article  Google Scholar 

  35. Ruiz-Tijerina, D. A. & Fal’ko, V. I. Interlayer hybridization and moiré superlattice minibands for electrons and excitons in heterobilayers of transition-metal dichalcogenides. Phys. Rev. B 99, 125424 (2019).

    Article  CAS  Google Scholar 

  36. Hubert, C. et al. Attractive dipolar coupling between stacked exciton fluids. Phys. Rev. X 9, 021026 (2019).

    CAS  Google Scholar 

  37. Ribeiro-Palau, R. et al. Twistable electronics with dynamically rotatable heterostructures. Science 361, 690–693 (2018).

    Article  CAS  Google Scholar 

  38. Sammon, M. & Shklovskii, B. I. Attraction of indirect excitons in van der Waals heterostructures with three semiconducting layers. Phys. Rev. B 99, 165403 (2019).

    Article  CAS  Google Scholar 

  39. Stern, M., Umansky, V. & Bar-Joseph, I. Exciton liquid in coupled quantum wells. Science 343, 55–57 (2014).

    Article  CAS  Google Scholar 

  40. Wang, Z. et al. Evidence of high-temperature exciton condensation in two-dimensional atomic double layers. Nature 574, 76–80 (2019).

    Article  CAS  Google Scholar 

  41. Brown, L. et al. Twinning and twisting of tri- and bilayer graphene. Nano Lett. 12, 1609–1615 (2012).

    Article  CAS  Google Scholar 

  42. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169 (1996).

    Article  CAS  Google Scholar 

  43. Bronsema, K. D., De Boer, J. L. & Jellinek, F. On the structure of molybdenum diselenide and disulfide. Z. Anorg. Allg. Chem. 540, 15–17 (1986).

    Article  Google Scholar 

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Acknowledgements

We thank B. Urbaszek for helpful discussions. We acknowledge support from the DoD Vannevar Bush Faculty Fellowship (N00014-16-1-2825 for H.P., N00014-18-1-2877 for P.K.), NSF (PHY-1506284 for H.P. and M.D.L.), NSF CUA (PHY-1125846 for H.P. and M.D.L.), AFOSR MURI (FA9550-17-1-0002), ARL (W911NF1520067 for H.P. and M.D.L.), the Gordon and Betty Moore Foundation (GBMF4543 for P.K.), ONR MURI (N00014-15-1-2761 for P.K.), and Samsung Electronics (for P.K. and H.P.). V.I.F. acknowledges EPSRC grants no. EP/S019367/1, EP/S030719/1, EP/N010345/1, ERC Synergy Grant Hetero2D, Lloyd’s Register Foundation Nanotechnology Grant, European Graphene Flagship Project and European Quantum Technologies Project 2D-SIPC. The device fabrication was carried out at the Harvard Center for Nanoscale Systems. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan and the CREST (JPMJCR15F3), JST. D.B. acknowledges support from the Summer Undergraduate Research Fellowship at Caltech.

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Authors and Affiliations

  1. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA

    Jiho Sung, You Zhou, Hoseok Heo & Hongkun Park

  2. Department of Physics, Harvard University, Cambridge, MA, USA

    Jiho Sung, You Zhou, Giovanni Scuri, Trond I. Andersen, Hyobin Yoo, Dominik S. Wild, Andrew Y. Joe, Ryan J. Gelly, Hoseok Heo, Mikhail D. Lukin, Philip Kim & Hongkun Park

  3. National Graphene Institute, University of Manchester, Manchester, UK

    Viktor Zólyomi, Samuel J. Magorrian & Vladimir I. Fal’ko

  4. Hartree Centre, STFC Daresbury Laboratory, Daresbury, UK

    Viktor Zólyomi

  5. Department of Physics, Sogang University, Seoul, Republic of Korea

    Hyobin Yoo

  6. Department of Physics, California Institute of Technology, Pasadena, CA, USA

    Damien Bérubé

  7. John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA

    Andrés M. Mier Valdivia & Philip Kim

  8. National Institute for Materials Science, Tsukuba, Japan

    Takashi Taniguchi & Kenji Watanabe

  9. Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK

    Vladimir I. Fal’ko

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Contributions

H.P., P.K., J.S., Y.Z., G.S., H.Y. and D.S.W. conceived the study, and J.S., Y.Z., G.S., T.I.A, A.Y.J., R.J.G., D.B. and A.M.M.V. fabricated the devices and performed the optical spectroscopy. H.P. V.I.F. J.S., Y.Z., G.S., V.Z., T.I.A. and D.S.W. analysed the data. V.I.F., V.Z. and S.J.M. performed the DFT calculations. H.Y. performed electron microscopy measurements. H.H. performed MoSe2 crystal growth. T.T. and K.W. performed h-BN crystal growth. J.S., Y.Z., G.S., T.I.A, M.D.L., P.K., V.I.F. and H.P. wrote the manuscript with extensive input from all authors. H.P., V.I.F., P.K. and M.D.L. supervised the project.

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Correspondence to Vladimir I. Fal’ko or Hongkun Park.

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Sung, J., Zhou, Y., Scuri, G. et al. Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe2/MoSe2 bilayers. Nat. Nanotechnol. 15, 750–754 (2020). https://doi.org/10.1038/s41565-020-0728-z

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