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.

  • Letter
  • Published:

Dirac electron states formed at the heterointerface between a topological insulator and a conventional semiconductor

Nature Materials volume 13, pages 253–257 (2014)Cite this article

Abstract

Topological insulators are a class of semiconductor exhibiting charge-gapped insulating behaviour in the bulk, but hosting a spin-polarized massless Dirac electron state at the surface1,2,3,4 . The presence of a topologically protected helical edge channel has been verified for the vacuum-facing surface of several topological insulators by means of angle-resolved photoemission spectroscopy5,6,7 and scanning tunnelling microscopy8,9,10 . By performing tunnelling spectroscopy on heterojunction devices composed of p-type topological insulator (Bi1−xSbx)2Te3 and n-type conventional semiconductor InP, we report the observation of such states at the solid-state interface. Under an applied magnetic field, we observe a resonance in the tunnelling conductance through the heterojunction due to the formation of Landau levels of two-dimensional Dirac electrons at the interface. Moreover, resonant tunnelling spectroscopy reveals a systematic dependence of the Fermi velocity and Dirac point energy on the composition x. The successful formation of robust non-trivial edge channels at a solid-state interface is an essential step towards functional junctions based on topological insulators11,12,13 .

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

Access options

Subscription info for Japanese customers

We have a dedicated website for our Japanese customers. Please go to natureasia.com to subscribe to this journal.

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF

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

Figure 1: Tunnelling spectroscopy in a topological insulator/non-topological insulator p–n junction.
Figure 2: Landau-level formation observed in tunnelling spectra.
Figure 3: Angular dependence of Landau-level formation.
Figure 4: Composition dependence of Fermi velocity and energy of Dirac point in (Bi1 −xSbx)2Te3.

Similar content being viewed by others

References

  1. Kane, C. L. & Mele, E. J. Z2 topological order and the quantum spin Hall effect. Phys. Rev. Lett. 95, 146802 (2005).

    Article CAS Google Scholar

  2. Fu, L., Kane, C. L. & Mele, E. J. Topological insulators in three dimensions. Phys. Rev. Lett. 98, 106803 (2007).

    Article Google Scholar

  3. Moore, J. E. & Balents, L. Topological invariants of time-reversal-invariant band structures. Phys. Rev. B 75, 121306(R) (2007).

    Article Google Scholar

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

    Article CAS Google Scholar

  5. Hsieh, D. et al. A topological Dirac insulator in a quantum spin Hall phase. Nature 452, 970–974 (2008).

    Article CAS Google Scholar

  6. Chen, Y. L. et al. Experimental realization of a three-dimensional topological insulator, Bi2Te3 . Science 325, 178–181 (2009).

    Article CAS Google Scholar

  7. Hsieh, D. et al. A tunable topological insulator in the spin helical Dirac transport regime. Nature 460, 1101–1105 (2009).

    Article CAS Google Scholar

  8. Cheng, P. et al. Landau quantization of topological surface states in Bi2Se3 . Phys. Rev. Lett. 105, 076801 (2010).

    Article Google Scholar

  9. Hanaguri, T., Igarashi, K., Kawamura, M., Takagi, H. & Sasagawa, T. Momentum-resolved Landau-level spectroscopy of Dirac surface state in Bi2Se3 . Phys. Rev. B 82, 081305(R) (2010).

    Article Google Scholar

  10. Jiang, Y. et al. Landau quantization and the thickness limit of topological insulator thin films of Sb2Te3 . Phys. Rev. Lett. 108, 016401 (2012).

    Article Google Scholar

  11. Fu, L. & Kane, C. L. Superconducting proximity effect and Majorana fermions at the surface of a topological insulator. Phys. Rev. Lett. 100, 096407 (2008).

    Article Google Scholar

  12. Qi, X. L., Hughes, T. L. & Zhang, S. C. Topological field theory of time-reversal invariant insulators. Phys. Rev. B 78, 195424 (2008).

    Article Google Scholar

  13. Seradjeh, B., Moore, J. E. & Franz, M. Exciton condensation and charge fractionalization in a topological insulator film. Phys. Rev. Lett. 103, 066402 (2009).

    Article CAS Google Scholar

  14. Klein, J., Leger, A., Belin, M., Defourneau, D. & Sangster, M. J. L. Inelastic-electron-tunneling spectroscopy of metal–insulator–metal junctions. Phys. Rev. B 7, 2336–2348 (1973).

    Article CAS Google Scholar

  15. Bockenhoff, E., Klitzing, K. V. & Ploog, K. Tunneling from accumulation layers in high magnetic fields. Phys. Rev. B 38, 10120–10123 (1988).

    Article CAS Google Scholar

  16. Yang, C. H., Yang, M. J. & Kao, Y. C. Magnetotunneling spectroscopy in a double-barrier heterostructure: Observation of incoherent resonant-tunneling processes. Phys. Rev. B 40, 6272–6276 (1989).

    Article CAS Google Scholar

  17. Zhang, J. et al. Band structure engineering in (Bi1−xSbx)2Te3 ternary topological insulators. Nature Commun. 2, 574 (2011).

    Article Google Scholar

  18. Qu, D. X., Hor, Y. S., Xiong, J., Cava, R. J. & Ong, N. P. Quantum oscillations and Hall anomaly of surface states in the topological insulator Bi2Te3 . Science 329, 821 (2010).

    Article CAS Google Scholar

  19. Analytis, J. G. et al. Two-dimensional surface state in the quantum limit of a topological insulator. Nature Phys. 6, 960–964 (2010).

    Article CAS Google Scholar

  20. Taskin, A. A., Ren, Z., Sasaki, S., Segawa, K. & Ando, Y. Observation of Dirac holes and electrons in a topological insulator. Phys. Rev. Lett. 107, 016801 (2011).

    Article CAS Google Scholar

  21. Sacepe, B. et al. Gate-tuned normal and superconducting transport at the surface of a topological insulator. Nature Commun. 2, 575 (2011).

    Article Google Scholar

  22. Levinstein, M., Rumyantsev, S. & Shur, M. Handbook Series on Semiconductor Parameters (World Scientific, (1996).

    Book Google Scholar

  23. Hao, G. et al. Synthesis and characterization of few-layer Sb2Te3 nanoplates with electrostatic properties. RSC Advances 2, 10694–10699 (2012).

    Article CAS Google Scholar

  24. Esaki, L. New phenomenon in narrow germanium p–n junctions. Phys. Rev. 109, 603–604 (1958).

    Article CAS Google Scholar

  25. Winkler, R. Spin–Orbit Coupling Effects in Two-Dimensional Electron and Hole Systems (Springer, (2003).

    Book Google Scholar

  26. Xiong, J. et al. High-field Shubnikov–de Haas oscillations in the topological insulator Bi2Te2Se. Phys. Rev. B 86, 045314 (2012).

    Article Google Scholar

  27. Chen, J. et al. Gate-voltage control of chemical potential and weak antilocalization in Bi2Se3 . Phys. Rev. Lett. 105, 176602 (2010).

    Article CAS Google Scholar

Download references

Acknowledgements

This research was supported by the Japan Society for the Promotion of Science through the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program) on ‘Quantum Science on Strong Correlation’ initiated by the Council for Science and Technology Policy and by JSPS Grant-in-Aid for Scientific Research(S) No. 24224009 and No. 24226002.

Author information

Author notes

  1. A. Tsukazaki

    Present address: Present address: Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.,

  2. R. Yoshimi and A. Tsukazaki: These authors equally contributed to this work.

Authors and Affiliations

  1. Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan

    R. Yoshimi, A. Tsukazaki, K. Kikutake, J. G. Checkelsky, M. Kawasaki & Y. Tokura

  2. Department of Advanced Materials Science, University of Tokyo Kashiwa Chiba 277-8561Japan,

    A. Tsukazaki

  3. RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan

    K. S. Takahashi, M. Kawasaki & Y. Tokura

Authors
  1. R. Yoshimi
  2. A. Tsukazaki
  3. K. Kikutake
  4. J. G. Checkelsky
  5. K. S. Takahashi
  6. M. Kawasaki
  7. Y. Tokura

Contributions

Y.T. conceived the project. R.Y. and K.K. grew the thin films, made the devices and performed the tunnelling spectroscopy measurements. R.Y. analysed the data and wrote the manuscript with contributions from all authors. A.T., J.G.C., K.S.T., M.K. and Y.T. jointly discussed the results.

Corresponding author

Correspondence to R. Yoshimi.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1105 kb)

About this article

Cite this article

Yoshimi, R., Tsukazaki, A., Kikutake, K. et al. Dirac electron states formed at the heterointerface between a topological insulator and a conventional semiconductor. Nature Mater 13, 253–257 (2014). https://doi.org/10.1038/nmat3885

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue date:

  • DOI: https://doi.org/10.1038/nmat3885

This article is cited by

Search

Advanced search

Quick links

[画像: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

AltStyle によって変換されたページ (->オリジナル) /