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Direct evidence of two-dimensional electron gas-like band structures in hafnene

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Abstract

Two-dimensional (2D) honeycomb-like materials have been widely studied due to their fascinating properties. In particular, 2D honeycomb-like transition metal monolayers, which are good 2D ferromagnet candidates, have attracted intense research interest. The honeycomb-like structure of hafnium, hafnene, has been successfully fabricated on the Ir(111) substrate. However, its electronic structure has not yet been directly elucidated. Here, we report the electronic structure of hafnene grown on the Ir(111) substrate using angle-resolved photoemission spectroscopy (ARPES). Our results indicate that the presence of spin-orbit coupling and Hubbard interaction suppresses the earlier predicted Dirac cones at the K points of the Brillouin zone. The observed band structure of hafnene near the Fermi level is very simple: an electron pocket centered at the Γ point of the Brillouin zone. This electron pocket shows typical parabolic dispersion, and its estimated electron effective mass and electron density are approximately 1.8 me and 7 × 1014 cm−2, respectively. Our results demonstrate the existence of 2D electron gas in hafnene grown on the Ir(111) substrate and therefore provide key information for potential hafnene-based device applications.

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References

  1. Novoselov, K. S.; Jiang, D.; Schedin, F.; Booth, T. J.; Khotkevich, V. V.; Morozov, S. V.; Geim, A. K. Two-dimensional atomic crystals. Proc. Natl. Acad. Sci. USA 2005, 102, 10451–10453.

    Article  CAS  Google Scholar 

  2. Geim, A. K.; Novoselov, K. S. The rise of graphene. Nat. Mater. 2007, 6, 183–191.

    Article  CAS  Google Scholar 

  3. Butler, S. Z.; Hollen, S. M.; Cao, L. Y.; Cui, Y.; Gupta, J. A.; Gutiérrez, H. R.; Heinz, T. F.; Hong, S. S.; Huang, J. X.; Ismach, A. F. et al. Progress, challenges, and opportunities in two-dimensional materials beyond graphene. ACS Nano 2013, 7, 2898–2926.

    CAS  Google Scholar 

  4. Xu, M. S.; Liang, T.; Shi, M. M.; Chen, H. Z. Graphene-like two-dimensional materials. Chem. Rev. 2013, 113, 3766–3798.

    Article  CAS  Google Scholar 

  5. Das, S.; Robinson, J. A.; Dubey, M.; Terrones, H.; Terrones, M. Beyond graphene: Progress in novel two-dimensional materials and van der Waals solids. Annu. Rev. Mater. Res. 2015, 45, 1–27.

    Article  CAS  Google Scholar 

  6. Vogt, P.; De Padova, P.; Quaresima, C.; Avila, J.; Frantzeskakis, E.; Asensio, M. C.; Resta, A.; Ealet, B.; Le Lay, G. Silicene: Compelling experimental evidence for graphenelike two-dimensional silicon. Phys. Rev. Lett. 2012, 108, 155501.

    Article  Google Scholar 

  7. Feng, B. J.; Ding, Z. J.; Meng, S.; Yao, Y. G.; He, X. Y.; Cheng, P.; Chen, L.; Wu, K. H. Evidence of Silicene in honeycomb structures of silicon on Ag(111). Nano Lett. 2012, 12, 3507–3511.

    Article  CAS  Google Scholar 

  8. Fleurence, A.; Friedlein, R.; Ozaki, T.; Kawai, H.; Wang, Y.; Yamada-Takamura, Y. Experimental evidence for epitaxial silicene on diboride thin films. Phys. Rev. Lett. 2012, 108, 245501.

    Article  Google Scholar 

  9. Meng, L.; Wang, Y. L.; Zhang, L. Z.; Du, S. X.; Wu, R. T.; Li, L. F.; Zhang, Y.; Li, G.; Zhou, H. T.; Hofer, W. A. et al. Buckled silicene formation on Ir(111). Nano Lett. 2013, 13, 685–690.

    Article  CAS  Google Scholar 

  10. Derivaz, M.; Dentel, D.; Stephan, R.; Hanf, M. C.; Mehdaoui, A.; Sonnet, P.; Pirri, C. Continuous germanene layer on Al(111). Nano Lett. 2015, 15, 2510–2516.

    Article  CAS  Google Scholar 

  11. Zhang, L.; Bampoulis, P.; Rudenko, A. N.; Yao, Q.; van Houselt, A.; Poelsema, B.; Katsnelson, M. I.; Zandvliet, H. J. W. Structural and electronic properties of germanene on MoS2. Phys. Rev. Lett. 2016, 116, 256804.

    Article  CAS  Google Scholar 

  12. Li, L. F.; Lu, S. Z.; Pan, J. B.; Qin, Z. H.; Wang, Y. Q.; Wang, Y. L.; Cao, G. Y.; Du, S. X.; Gao, H. J. Buckled germanene formation on Pt(111). Adv. Mater. 2014, 26, 4820–4824.

    Article  CAS  Google Scholar 

  13. Li, L. K.; Yu, Y. J.; Ye, G. J.; Ge, Q. Q.; Ou, X. D.; Wu, H.; Feng, D. L.; Chen, X. H.; Zhang, Y. B. Black phosphorus field-effect transistors. Nat. Nanotechnol. 2014, 9, 372–377.

    Article  CAS  Google Scholar 

  14. Li, X. R.; Dai, Y.; Ma, Y. D.; Huang, B. B. Electronic and magnetic properties of honeycomb transition metal monolayers: First-principles insights. Phys. Chem. Chem. Phys. 2014, 16, 13383–13389.

    Article  CAS  Google Scholar 

  15. Li, L. F.; Wang, Y. L.; Xie, S. Y.; Li, X. B.; Wang, Y. Q.; Wu, R. T.; Sun, H. B.; Zhang, S. B.; Gao, H. J. Two-dimensional transition metal honeycomb realized: Hf on Ir(111). Nano Lett. 2013, 13, 4671–4674.

    Article  CAS  Google Scholar 

  16. Pan, Y.; Zhang, L. Z.; Huang, L.; Li, L. F.; Meng, L.; Gao, M.; Huan, Q.; Lin, X.; Wang, Y. L.; Du, S. X. et al. Construction of 2D atomic crystals on transition metal surfaces: Graphene, silicene, and hafnene. Small 2014, 10, 2215–2225.

    Article  CAS  Google Scholar 

  17. Zhou, B. Z.; Dong, S. J.; Wang, X. C.; Zhang, K. L. Prediction of two-dimensional d-block elemental materials with normal honeycomb, triangular-dodecagonal, and square-octagonal structures from first principles. Appl. Surf. Sci. 2017, 419, 484–496.

    Article  CAS  Google Scholar 

  18. Hashmi, A.; Farooq, M. U.; Khan, I.; Hong, J. S. Two-dimensional honeycomb hafnene monolayer: Stability and magnetism by structural transition. Nanoscale 2017, 9, 10038–10043.

    Article  CAS  Google Scholar 

  19. Tadele, K.; Zhang, Q. F.; Wang, B. L. Formation and structural growth of two dimensional layer of hafnene on Ir(111) surface. Chem. Phys. Lett. 2018, 712, 60–65.

    Article  CAS  Google Scholar 

  20. Kresse, G.; Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 1996, 54, 11169–11186.

    Article  CAS  Google Scholar 

  21. Kresse, G.; Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999, 59, 1758–1775.

    Article  CAS  Google Scholar 

  22. Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865–3868.

    Article  CAS  Google Scholar 

  23. Liechtenstein, A. I.; Anisimov, V. I.; Zaanen, J. Density-functional theory and strong interactions: Orbital ordering in Mott-Hubbard insulators. Phys. Rev. B 1995, 52, R5467–R5470.

    Article  CAS  Google Scholar 

  24. Medeiros, P. V. C.; Stafström, S.; Björk, J. Effects of extrinsic and intrinsic perturbations on the electronic structure of graphene: Retaining an effective primitive cell band structure by band unfolding. Phys. Rev. B 2014, 89, 041407.

    Article  Google Scholar 

  25. Medeiros, P. V. C.; Tsirkin, S. S.; Stafström, S.; Björk, J. Unfolding spinor wave functions and expectation values of general operators: Introducing the unfolding-density operator. Phys. Rev. B 2015, 91, 041116.

    Article  Google Scholar 

  26. Riedl, C.; Coletti, C.; Iwasaki, T.; Zakharov, A. A.; Starke, U. Quasifree-standing epitaxial graphene on SiC obtained by hydrogen intercalation. Phys. Rev. Lett. 2009, 103, 246804.

    Article  CAS  Google Scholar 

  27. Briggs, N.; Gebeyehu, Z. M.; Vera, A.; Zhao, T.; Wang, K.; Duran, A. D. L. F.; Bersch, B.; Bowen, T.; Knappenberger, K. L. Jr.; Robinson, J. A. Epitaxial graphene/silicon carbide intercalation: A minireview on graphene modulation and unique 2D materials. Nanoscale 2019, 11, 15440–15447.

    Article  CAS  Google Scholar 

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Acknowledgements

This work is supported by the National Key Research and Development Program of China (Nos. 2017YFA0303600 and 2020YFA0308800), the National Natural Science Foundation of China (Nos. 11974364, 11674367, U2032207, 92163206, 11974045, and 61725107), the Natural Science Foundation of Zhejiang, China (No. LZ18A040002), and the Ningbo Science and Technology Bureau (No. 2018B10060). S. L. H. would like also to acknowledge the Ningbo 3315 program.

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Correspondence to Jiatao Sun, Yeliang Wang or Shaolong He.

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Xiao, S., Liu, M., Li, L. et al. Direct evidence of two-dimensional electron gas-like band structures in hafnene. Nano Res. 15, 3770–3774 (2022). https://doi.org/10.1007/s12274-021-3920-z

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