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Epitaxial growth of ultraflat stanene with topological band inversion

Abstract

Two-dimensional (2D) topological materials, including quantum spin/anomalous Hall insulators, have attracted intense research efforts owing to their promise for applications ranging from low-power electronics and high-performance thermoelectrics to fault-tolerant quantum computation. One key challenge is to fabricate topological materials with a large energy gap for room-temperature use. Stanene—the tin counterpart of graphene—is a promising material candidate distinguished by its tunable topological states and sizeable bandgap. Recent experiments have successfully fabricated stanene, but none of them have yet observed topological states. Here we demonstrate the growth of high-quality stanene on Cu(111) by low-temperature molecular beam epitaxy. Importantly, we discovered an unusually ultraflat stanene showing an in-plane s–p band inversion together with a spin–orbit-coupling-induced topological gap (~0.3 eV) at the Γ point, which represents a foremost group-IV ultraflat graphene-like material displaying topological features in experiment. The finding of ultraflat stanene opens opportunities for exploring two-dimensional topological physics and device applications.

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Fig. 1: Atomic and electronic structures of ultraflat stanene on Cu(111).
Fig. 2: Calculated atomic and electronic structures of the ultraflat stanene.
Fig. 3: Edge structure and edge states of the ultraflat stanene flakes.
Fig. 4: Atomically resolved line defect and point defects in the ultraflat stanene.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Hasan, M. Z. & Kane, C. L. Colloquium: Topological insulators. Rev. Mod. Phys. 82, 3045–3067 (2010).

    CAS  Article  Google Scholar 

  2. Qi, X. L. & Zhang, S. C. Topological insulators and superconductors. Rev. Mod. Phys. 83, 1057–1110 (2011).

    CAS  Article  Google Scholar 

  3. Bernevig, B. A., Hughes, T. L. & Zhang, S. C. Quantum spin Hall effect and topological phase transition in HgTe quantum wells. Science 314, 1757–1761 (2006).

    CAS  Article  Google Scholar 

  4. König, M. et al. Quantum spin Hall insulator state in HgTe quantum wells. Science 318, 766–770 (2007).

    Article  Google Scholar 

  5. Liu, C., Hughes, T. L., Qi, X. L., Wang, K. & Zhang, S. C. Quantum spin Hall effect in inverted type-II semiconductors. Phys. Rev. Lett. 100, 236601 (2008).

    Article  Google Scholar 

  6. Knez, I., Du, R. R. & Sullivan, G. Evidence for helical edge modes in inverted InAs/GaSb quantum wells. Phys. Rev. Lett. 107, 136603 (2011).

    Article  Google Scholar 

  7. Chang, C. Z. et al. Experimental observation of the quantum anomalous Hall effect in a magnetic topological insulator. Science 340, 167–170 (2013).

    CAS  Article  Google Scholar 

  8. Kane, C. L. & Mele, E. J. Quantum spin Hall effect in graphene. Phys. Rev. Lett. 95, 226801 (2005).

    CAS  Article  Google Scholar 

  9. Liu, C. C., Feng, W. X. & Yao, Y. G. Quantum spin Hall effect in silicene and two-dimensional germanium. Phys. Rev. Lett. 107, 076802 (2011).

    Article  Google Scholar 

  10. Xu, Y. et al. Large-gap quantum spin Hall insulators in tin films. Phys. Rev. Lett. 111, 136804 (2013).

    Article  Google Scholar 

  11. Qian, X. F., Liu, J. W., Fu, L. & Li, J. Quantum spin Hall effect in two-dimensional transition metal dichalcogenides. Science 346, 1344–1347 (2014).

    CAS  Article  Google Scholar 

  12. Molle, A. et al. Buckled two-dimensional Xene sheets. Nat. Mater. 16, 163–169 (2017).

    CAS  Article  Google Scholar 

  13. Vogt, P. et al. Silicene: compelling experimental evidence for graphenelike two-dimensional silicon. Phys. Rev. Lett. 108, 155501 (2012).

    Article  Google Scholar 

  14. Feng, B. J. et al. Evidence of silicene in honeycomb structures of silicon on Ag(111). Nano. Lett. 12, 3507–3511 (2012).

    CAS  Article  Google Scholar 

  15. Dávila, M. E., Xian, L., Cahangirov, S., Rubio, A. & Le Lay, G. Germanene: a novel two-dimensional germanium allotrope akin to graphene and silicene. New J. Phys. 16, 095002 (2014).

    Article  Google Scholar 

  16. Li, L. F. et al. Buckled germanene formation on Pt(111). Adv. Mater. 26, 4820–4824 (2014).

    CAS  Article  Google Scholar 

  17. Zhu, F. F. et al. Epitaxial growth of two-dimensional stanene. Nat. Mater. 14, 1020–1025 (2015).

    CAS  Article  Google Scholar 

  18. Liu, Z. et al. Stable nontrivial Z2 topology in ultrathin Bi (111) films: A first-principles study. Phys. Rev. Lett. 107, 136805 (2011).

    Article  Google Scholar 

  19. Reis, F. et al. Bismuthene on a SiC substrate: A candidate for a high-temperature quantum spin Hall material. Science 357, 287–290 (2017).

    CAS  Article  Google Scholar 

  20. Wu, S. F. et al. Observation of the quantum spin Hall effect up to 100 kelvin in a monolayer crystal. Science 359, 76–79 (2018).

    CAS  Article  Google Scholar 

  21. Tang, S. J. et al. Quantum spin Hall state in monolayer 1T’-WTe2. Nat. Phys. 13, 683–687 (2017).

    CAS  Article  Google Scholar 

  22. Fei, Z. Y. et al. Edge conduction in monolayer WTe2. Nat. Phys. 13, 677–682 (2017).

    CAS  Article  Google Scholar 

  23. Xu, Y., Gan, Z. X. & Zhang, S. C. Enhanced thermoelectric performance and anomalous Seebeck effects in topological insulators. Phys. Rev. Lett. 112, 226801 (2014).

    Article  Google Scholar 

  24. Wu, S. C., Shan, G. C. & Yan, B. H. Prediction of near-room-temperature quantum anomalous Hall effect on honeycomb materials. Phys. Rev. Lett. 113, 256401 (2014).

    Article  Google Scholar 

  25. Wang, J., Xu, Y. & Zhang, S. C. Two-dimensional time-reversal-invariant topological superconductivity in a doped quantum spin-Hall insulator. Phys. Rev. B 90, 054503 (2014).

    Article  Google Scholar 

  26. Gou, J. et al. Strain-induced band engineering in monolayer stanene on Sb(111). Phys. Rev. Mater. 1, 054004 (2017).

    Article  Google Scholar 

  27. Zang, Y. Y. et al. Realizing an epitaxial decorated stanene with an insulating bandgap. Adv. Funct. Mater. 28, 1802723 (2018).

    Article  Google Scholar 

  28. Song, Y. H. et al. High-buckled R3 stanene with topologically nontrivial energy gap. Preprint at https://arxiv.org/abs/1707.08657 (2017).

  29. Xu, C.-Z. et al. Gapped electronic structure of epitaxial stanene on InSb(111). Phys. Rev. B 97, 035122 (2018).

    CAS  Article  Google Scholar 

  30. Yuhara, J. et al. Large area planar stanene epitaxially grown on Ag(1 1 1). 2D Mater. 5, 025002 (2018).

    Article  Google Scholar 

  31. Liao, M. H. et al. Superconductivity in few-layer stanene. Nat. Phys. 14, 344–348 (2018).

    CAS  Article  Google Scholar 

  32. Zhou, M. et al. Epitaxial growth of large-gap quantum spin Hall insulator on semiconductor surface. Proc. Natl Acad. Sci. USA 111, 14378–14381 (2014).

    CAS  Article  Google Scholar 

  33. Zhang, G. F., Li, Y. & Wu, C. J. Honeycomb lattice with multiorbital structure: Topological and quantum anomalous Hall insulators with large gaps. Phys. Rev. B 90, 075114 (2014).

    Article  Google Scholar 

  34. Wu, C. J., Bergman, D., Balents, L. & Sarma, S. D. Flat bands and Wigner crystallization in the honeycomb optical lattice. Phys. Rev. Lett. 99, 070401 (2007).

    Article  Google Scholar 

  35. Yan, B. H. et al. Topological states on the gold surface. Nat. Commun. 6, 10167 (2015).

    CAS  Article  Google Scholar 

  36. Son, Y. W., Cohen, M. L. & Louie, S. G. Half-metallic graphene nanoribbons. Nature 444, 347–349 (2006).

    CAS  Article  Google Scholar 

  37. Yazyev, O. V. & Helm, L. Defect-induced magnetism in graphene. Phys. Rev. B 75, 125408 (2007).

    Article  Google Scholar 

  38. Lahiri, J., Lin, Y., Bozkurt, P., Oleynik, I. I. & Batzill, M. An extended defect in graphene as a metallic wire. Nat. Nanotech. 5, 326–329 (2010).

    CAS  Article  Google Scholar 

  39. Huang, P. Y. et al. Grains and grain boundaries in single-layer graphene atomic patchwork quilts. Nature 469, 389–392 (2011).

    CAS  Article  Google Scholar 

  40. Ma, C. X. et al. Evidence of van Hove singularities in ordered grain boundaries of graphene. Phys. Rev. Lett. 112, 226802 (2014).

    Article  Google Scholar 

  41. Tao, L. et al. Silicene field-effect transistors operating at room temperature. Nat. Nanotech. 10, 227–231 (2015).

    CAS  Article  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).

    CAS  Article  Google Scholar 

  43. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953 (1994).

    Article  Google Scholar 

  44. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    CAS  Article  Google Scholar 

  45. Mostofi, A. A. et al. wannier90: A tool for obtaining maximally-localised Wannier functions. Comput. Phys. Commun. 178, 685–699 (2008).

    CAS  Article  Google Scholar 

  46. Wu, Q. S., Zhang, S. N., Song, H.-F., Troyer, M. & Soluyanov, A. A. Wannier Tools: An open-source software package for novel topological materials. Comput. Phys. Commun. 224, 4059–4416 (2018).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Key R&D Program of China (grants nos 2016YFA0200603, 2017YFA0205004, 2018YFA0305603, 2016YFA0301001, 2018YFA0307100), the ‘Strategic Priority Research Program’ of CAS (XDB01020100), the National Natural Science Foundation of China (grants nos 91321309, 51132007, 21421063, 21473174, 21273210, 51788104), and the Fundamental Research Funds for the Central Universities (WK2060190084, WK2340000065). A.Z. acknowledges a fellowship from the Youth Innovation Promotion Association of CAS (2011322). Y.X. acknowledges support from the Tsinghua University Initiative Scientific Research Program and the National Thousand-Young-Talents Program. The calculations were done on the ‘Explorer 100’ cluster system of Tsinghua University and on the ‘Tianhe-2’ of the National Supercomputer Computer Center in Guangzhou. W.D. acknowledge support from the National Natural Science Foundation of China (grants nos 11674188 and 11334006), and the Beijing Advanced Innovation Center for Future Chip (ICFC). S.-C.Z. is supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Contract No. DE-AC02-76SF00515.

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Contributions

A.Z., Y.X., B.W., W.D., S.-C.Z. and J.G.H. devised the experiments and provided financial and other support for the experiments and calculations. J.D. H.S. and X.Z. performed the MBE growth and STM/STS measurements. B.X., H.C., B.L. and Y.X. performed theoretical calculations. X.M. and J.D. performed the ARPES measurements. A.Z., Y.X., B.W., W.D., S.-C.Z. and J.G.H. analysed the data. A.Z. and Y.X. wrote the paper with input from other co-authors.

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Correspondence to Aidi Zhao, Yong Xu or Bing Wang.

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Supplementary Figures 1–9, Extended Discussion of Computational Results, Supplementary References 1–4

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Deng, J., Xia, B., Ma, X. et al. Epitaxial growth of ultraflat stanene with topological band inversion. Nature Mater 17, 1081–1086 (2018). https://doi.org/10.1038/s41563-018-0203-5

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