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.

  • Article
  • Published:

Spin polarization of the quantum spin Hall edge states

Nature Physics volume 8, pages 485–490 (2012)Cite this article

Subjects

Abstract

The prediction and experimental verification of the quantum spin Hall state marked the discovery of a new state of matter now known as topological insulators. Two-dimensional topological insulators exhibit the quantum spin-Hall effect, characterized by gapless spin-polarized counter-propagating edge channels. Whereas the helical character of these edge channels is now well established, experimental confirmation that the transport in the edge channels is spin polarized is still outstanding. We report experiments on nanostructures fabricated from HgTe quantum wells with an inverted band structure, in which a split gate technique allows us to combine both quantum spin Hall and metallic spin Hall transport in a single device. In these devices, the quantum spin Hall effect can be used as a spin current injector and detector for the metallic spin Hall effect, and vice versa, allowing for an all-electrical detection of spin polarization.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Schematic layout of the two experiments on split-gated H-bar devices discussed in this paper.
Figure 2: Characterization of devices.
Figure 3: Experimental non-local resistance data corresponding to the measurement configuration of Fig. 1a.
Figure 4: Experimental non-local resistance data corresponding to the measurement configuration of Fig. 1b.
Figure 5: Semiclassical Monte Carlo simulation of the non-local resistance.

Similar content being viewed by others

References

  1. 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).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  3. König, M. et al. The quantum spin Hall effect: Theory and experiment. J. Phys. Soc. Jpn 77, 031007 (2008).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  5. Bernevig, B. A. & Zhang, S. C. Quantum spin Hall effect. Phys. Rev. Lett. 96, 106802 (2006).

    Article  ADS  Google Scholar 

  6. Wu, C. J., Bernevig, B. A. & Zhang, S. C. Helical liquid and the edge of quantum spin Hall systems. Phys. Rev. Lett. 96, 106401 (2006).

    Article  ADS  Google Scholar 

  7. Xu, C. & Moore, J. Stability of the quantum spin Hall effect: Effects of interactions, disorder, and topology. Phys. Rev. B 73, 045322 (2006).

    Article  ADS  Google Scholar 

  8. Maciejko, J. et al. Kondo effect in the helical edge liquid of the quantum spin Hall state. Phys. Rev. Lett. 102, 256803 (2009).

    Article  ADS  Google Scholar 

  9. Roth, A. et al. Nonlocal transport in the quantum spin Hall state. Science 325, 294–297 (2009).

    Article  ADS  Google Scholar 

  10. Büttiker, M. Edge-state physics without magnetic fields. Science 325, 278–279 (2009).

    Article  Google Scholar 

  11. Hankiewicz, E. M., Molenkamp, L. W., Jungwirth, T. & Sinova, J. Manifestation of the spin Hall effect through charge-transport in the mesoscopic regime. Phys. Rev. B 70, 241301 (2004).

    Article  ADS  Google Scholar 

  12. Valenzuela, S. O. & Tinkham, M. Direct electronic measurement of the spin Hall effect. Nature 442, 176–179 (2006).

    Article  ADS  Google Scholar 

  13. Brüne, C. et al. Evidence for the ballistic intrinsic spin Hall effect in HgTe nanostructures. Nature Phys. 6, 448–454 (2010).

    Article  ADS  Google Scholar 

  14. Rothe, D. G. et al. Fingerprint of different spin-orbit terms for spin transport in HgTe quantum wells. New J. Phys. 12, 065012 (2010).

    Article  ADS  Google Scholar 

  15. Novik, E. G. et al. Band structure of semimagnetic Hg1−yMnyTe quantum wells. Phys. Rev. B 72, 035321 (2005).

    Article  ADS  Google Scholar 

  16. Hinz, J. et al. control of the giant Rashba effect in HgTe quantum wells. Semicond. Sci. Technol. 21, 501–506 (2006).

    Article  ADS  Google Scholar 

  17. Büttiker, M. Four-terminal phase-coherent conductance. Phys. Rev. Lett. 57, 1761–1764 (1986).

    Article  ADS  Google Scholar 

  18. Büttiker, M. Symmetry of electrical conduction. IBM J. Res. Dev. 32, 317–334 (1988).

    Article  Google Scholar 

  19. Beenakker, C. W. J. & van Houten, H. Billiard model of a ballistic multiprobe conductor. Phys. Rev. Lett. 63, 1857–1860 (1989).

    Article  ADS  Google Scholar 

  20. Sundaram, G. & Niu, Q. Wavepacket dynamics in slowly perturbed crystals: Gradient corrections and Berry-phase effects. Phys. Rev. B 59, 14915–14925 (1999).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank M. Leberecht and R. Rommel for assistance in some of the experiments andE. G. Novik for discussions of the band structure. We gratefully acknowledge financial support by the Deutsche Forschungsgemeinschaft (Schwerpunkt Spintronik) under grants HA 5893/1-2 (E.M.H.) and BU 1113/3-1 (H.B.), the German-Israeli Foundation (I-881-138.7/2005) the DFG-JST joint research project Topological Electronics, the National Science and Engineering Research Council (NSERC) of Canada and the Stanford Graduate Fellowship Program (SGF). S-C.Z. is supported by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract DE-AC02-76SF00515 and by the Keck Foundation. We agree the Leibniz Rechenzentrum Munich, the facilities of the Shared Hierarchical Academic Research Computing Network (www.sharcnet.ca) and the computing cluster of the Stanford Institute for Materials and Energy Science at the SLAC National Accelerator Laboratory for providing computer resources.

Author information

Authors and Affiliations

  1. Physikalisches Institut (EP3) and Röntgen Center for Complex Material Systems, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

    Christoph Brüne, Andreas Roth, Hartmut Buhmann & Laurens W. Molenkamp

  2. Institut für Theoretische und Astrophysik and Röntgen Center for Complex Material Systems, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

    Ewelina M. Hankiewicz

  3. Department of Physics, Stanford University, Stanford, California 94305, USA

    Joseph Maciejko, Xiao-Liang Qi & Shou-Cheng Zhang

  4. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA

    Joseph Maciejko, Xiao-Liang Qi & Shou-Cheng Zhang

  5. Microsoft Research Station Q, Elings Hall, University of California, Santa Barbara, California 93106, USA

    Xiao-Liang Qi

Authors
  1. Christoph Brüne
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Andreas Roth
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hartmut Buhmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Ewelina M. Hankiewicz
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Laurens W. Molenkamp
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Joseph Maciejko
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Xiao-Liang Qi
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Shou-Cheng Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

C.B., A.R., H.B. and L.W.M. have contributed to the experiments, E.M.H., J.M., X-L.Q. and S-C.Z. contributed to the theory. All authors have participated in the interpretation of the experiments. The paper was written by C.B., J.M., E.M.H., S-C.Z and L.W.M., and the Supplementary Information by J.M., X.L.Q. and E.M.H.

Corresponding author

Correspondence to Laurens W. Molenkamp.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 2033 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Brüne, C., Roth, A., Buhmann, H. et al. Spin polarization of the quantum spin Hall edge states. Nature Phys 8, 485–490 (2012). https://doi.org/10.1038/nphys2322

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys2322

This article is cited by

Search

Advanced search

Quick links

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