Letter | Published:

Discovery of a single topological Dirac fermion in the strong inversion asymmetric compound BiTeCl

Nature Physics volume 9, pages 704708 (2013) | Download Citation

Abstract

In the past few years, a new state of quantum matter known as the time-reversal-invariant topological insulator has been predicted theoretically and realized experimentally. All of the topological insulators discovered so far in experiment are inversion symmetric1,2,3,4,5—except for strained HgTe, which has weak inversion asymmetry, a small bulk gap but no bulk charge polarization6. Strong inversion asymmetry in topological insulators would not only lead to many interesting phenomena, such as crystalline-surface-dependent topological electronic states, pyroelectricity and intrinsic topological p–n junctions, but would also serve as an ideal platform for the realization of topological magneto-electric effects7,8, which result from the modification of Maxwell equations in topological insulators. Here we report the discovery of a strong inversion asymmetric topological insulator phase in BiTeCl by angle-resolved photoemission spectroscopy, which reveals Dirac surface states and crystalline-surface-dependent electronic structures. Moreover, we observe a tenfold increase of the bulk energy gap in BiTeCl over the weak inversion asymmetric topological insulator HgTe, making it a promising platform for topological phenomena and possible applications at high temperature.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & Colloquium: Topological insulators. Rev. Mod. Phys. 82, 3045–3067 (2010).

  2. 2.

    & Topological insulators and superconductors. Rev. Mod. Phys. 83, 1057–1110 (2011).

  3. 3.

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

  4. 4.

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

  5. 5.

    et al. Observation of a large-gap topological-insulator class with a single Dirac cone on the surface. Nature Phys. 5, 398–402 (2009).

  6. 6.

    et al. Single Dirac cone topological surface state and unusual thermoelectric property of compounds from a new topological insulator family. Phys. Rev. Lett. 105, 266401 (2010).

  7. 7.

    et al. Experimental realization of a three-dimensional topological insulator phase in ternary chalcogenide TlBiSe2. Phys. Rev. Lett. 105, 146801 (2010).

  8. 8.

    et al. Quantum Hall effect from the topological surface states of strained bulk HgTe. Phys. Rev. Lett. 106, 126803 (2011).

  9. 9.

    , & Topological field theory of time-reversal invariant insulators. Phys. Rev. B 78, 195424 (2008).

  10. 10.

    & Topological insulators with inversion symmetry. Phys. Rev. B 76, 045302 (2007).

  11. 11.

    et al. Tunable multifunctional topological insulators in ternary Heusler compounds. Nature Mater. 9, 541–545 (2010).

  12. 12.

    et al. Theoretical prediction of topological insulator in ternary rare earth chalcogenides. Phys. Rev. B 82, 161108 (2010).

  13. 13.

    , , & Emergence of non-centrosymmetric topological insulating phase in BiTeI under pressure. Nature Commun. 3, 679 (2012).

  14. 14.

    , , & Topological p-n junction. Phys. Rev. B 85, 235131 (2012).

  15. 15.

    , , , & Chern semimetal and the quantized anomalous Hall effect in HgCr2Se4. Phys. Rev. Lett. 107, 186806 (2011).

  16. 16.

    , , & Topological semimetal and Fermi-arc surface states in the electronic structure of pyrochlore iridates. Phys. Rev. B 83, 205101 (2011).

  17. 17.

    , & Topological invariants for the Fermi surface of a time-reversal-invariant superconductor. Phys. Rev. B 81, 134508 (2010).

  18. 18.

    , , , & Helical edge and surface states in HgTe quantum wells and bulk insulators. Phys. Rev. B 77, 125319 (2008).

  19. 19.

    et al. Giant Rashba-type spin splitting in bulk BiTeI. Nature Mater. 10, 521–526 (2011).

  20. 20.

    et al. Disentanglement of surface and bulk Rashba spin splittings in noncentrosymmetric BiTeI. Phys. Rev. Lett. 109, 116403 (2012).

  21. 21.

    et al. Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface. Nature Phys. 5, 438–442 (2009).

  22. 22.

    et al. Theoretical prediction of topological insulators in thallium-based III–V–VI2 ternary chalcogenides. Eur. Phys. Lett. 90, 37002 (2010).

  23. 23.

    CRC Handbook of Chemistry and Physics 93rd edn (CRC Press, 2012).

  24. 24.

    et al. Massive Dirac fermion on the surface of a magnetically doped topological insulator. Science 329, 659–662 (2010).

  25. 25.

    Studies on the electronic structures of three-dimensional topological insulators by angle resolved photoemission spectroscopy. Front. Phys. 7, 175–192 (2012).

  26. 26.

    & Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators. Physica Status Solidi 7, 64–71 (2013).

  27. 27.

    , , , & Ideal two-dimensional electron systems with a giant Rashba-type spin splitting in real materials: Surfaces of bismuth tellurohalides. Phys. Rev. Lett. 108, 246802 (2012).

  28. 28.

    et al. Environmentally friendly refining of diamond-molecules via the growth of large single crystals. Cryst. Growth Des. 10, 870–873 (2009).

  29. 29.

    & From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999).

  30. 30.

    , & Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

Download references

Acknowledgements

We thank Z. Wang and C. X. Liu for the helpful discussion. Y.L.C. acknowledges support from a DARPA MESO project (No. N66001-11-1-4105) and the EPSRC First Grant (EP/K04074X/1). B.Z., Z.K.L., Z.X.S. and X.L.Q. acknowledge support from Department of Energy, Office of Basic Energy Science (contract DE-AC02-76SF00515). T.S. acknowledges support from MEXT, Japan (Grant-in-Aid for Scientific Research (B), No. 24340078). H.J.Z. acknowledges support from the Army Research Office (No. W911NF-09-1-0508). J.A.S. acknowledges support from the Stanford Graduate Fellowship. D.L. acknowledges the Swiss National Science Foundation.

Author information

Affiliations

  1. Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK

    • Y. L. Chen
    •  & B. Zhou
  2. Diamond Light Source, Didcot OX11 0DE, UK

    • Y. L. Chen
  3. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

    • Y. L. Chen
    • , J. A. Sobota
    • , D. Leuenberger
    • , S-L. Yang
    • , P. S. Kirchmann
    • , R. G. Moore
    •  & Z. X. Shen
  4. Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan

    • M. Kanou
    •  & T. Sasagawa
  5. Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA

    • Z. K. Liu
    • , H. J. Zhang
    • , J. A. Sobota
    • , D. Leuenberger
    • , S-L. Yang
    • , Z. X. Shen
    •  & X. L. Qi
  6. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

    • S. K. Mo
    • , B. Zhou
    •  & Z. Hussain
  7. Stanford Synchrotron Radiation Lightsource, 2575 Sand Hill Road, California 94025, USA

    • D. H. Lu

Authors

  1. Search for Y. L. Chen in:

  2. Search for M. Kanou in:

  3. Search for Z. K. Liu in:

  4. Search for H. J. Zhang in:

  5. Search for J. A. Sobota in:

  6. Search for D. Leuenberger in:

  7. Search for S. K. Mo in:

  8. Search for B. Zhou in:

  9. Search for S-L. Yang in:

  10. Search for P. S. Kirchmann in:

  11. Search for D. H. Lu in:

  12. Search for R. G. Moore in:

  13. Search for Z. Hussain in:

  14. Search for Z. X. Shen in:

  15. Search for X. L. Qi in:

  16. Search for T. Sasagawa in:

Contributions

Y.L.C. and T.S. conceived the experiments. Y.L.C., Z.K.L. and J.A.S. carried out ARPES measurements with the assistance of S.K.M., D.H.L., R.G.M., M.K., D.L., S-L.Y. and P.S.K.; T.S. and M.K. synthesized and characterized bulk single crystals. H.J.Z. performed ab initio calculations and X.L.Q. provided the theory support. All authors contributed to the scientific planning and discussions.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Y. L. Chen or T. Sasagawa.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

Videos

  1. 1.

    Supplementary Movie

    Supplementary Movie 1

  2. 2.

    Supplementary Movie

    Supplementary Movie 2

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nphys2768

Further reading