Skip to main content

Thank you for visiting 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.

Stacked topological insulator built from bismuth-based graphene sheet analogues


Commonly, materials are classified as either electrical conductors or insulators. The theoretical discovery of topological insulators has fundamentally challenged this dichotomy. In a topological insulator, the spin–orbit interaction generates a non-trivial topology of the electronic band structure dictating that its bulk is perfectly insulating, whereas its surface is fully conducting. The first topological insulator candidate material put forward—graphene—is of limited practical use because its weak spin–orbit interactions produce a bandgap of ~ 0.01 K. Recent reexaminations of Bi2Se3 and Bi2Te3, however, have firmly categorized these materials as strong three-dimensional topological insulators. We have synthesized the first bulk material belonging to an entirely different, weak, topological class, built from stacks of two-dimensional topological insulators: Bi14Rh3I9. Its Bi–Rh sheets are graphene analogues, but with a honeycomb net composed of RhBi8 cubes rather than carbon atoms. The strong bismuth-related spin–orbit interaction renders each graphene-like layer a topological insulator with a 2,400 K bandgap.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Structure of Bi14Rh3I9 and its relation to graphene.
Figure 2: Electronic structure of Bi14Rh3I9 with and without spin–orbit interaction.
Figure 3: Band structure as measured by angle-resolved photoemission26 compared to the calculated one.


  1. 1

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

    CAS  Article  Google Scholar 

  2. 2

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

    CAS  Article  Google Scholar 

  3. 3

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

    CAS  Google Scholar 

  4. 4

    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 

  5. 5

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

    Article  Google Scholar 

  6. 6

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

    Article  Google Scholar 

  7. 7

    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 

  8. 8

    Akhmerov, A. R., Nilsson, J. & Beenakker, C. W. J. Electrically detected interferometry of Majorana fermions in a topological insulator. Phys. Rev. Lett. 102, 216404 (2009).

    CAS  Article  Google Scholar 

  9. 9

    Law, K. T., Lee, P. A. & Ng, T. K. Majorana fermion induced resonant Andreev reflection. Phys. Rev. Lett. 103, 237001 (2009).

    CAS  Article  Google Scholar 

  10. 10

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

    CAS  Article  Google Scholar 

  11. 11

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

    CAS  Article  Google Scholar 

  12. 12

    Hsieh, D. et al. Observation of time-reversal-protected single-Dirac-cone topological-insulator states in Bi2Te3 and Sb2Te3 . Phys. Rev. Lett. 103, 146401 (2009).

    CAS  Article  Google Scholar 

  13. 13

    Kuroda, K. et al. Experimental verification of PbBi2Te4 as a 3D topological insulator. Phys. Rev. Lett. 108, 206803 (2012).

    CAS  Article  Google Scholar 

  14. 14

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

    Article  Google Scholar 

  15. 15

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

    Article  Google Scholar 

  16. 16

    Min, H. et al. Intrinsic and Rashba spin–orbit interactions in graphene sheets. Phys. Rev. B 74, 165310 (2006).

    Article  Google Scholar 

  17. 17

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

    Article  Google Scholar 

  18. 18

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

    Article  Google Scholar 

  19. 19

    Roy, R. Topological phases and the quantum spin Hall effect in three dimensions. Phys. Rev. B 79, 195322 (2009).

    Article  Google Scholar 

  20. 20

    Koepernik, K. & Eschrig, H. Full-potential nonorthogonal local-orbital minimum-basis band-structure scheme. Phys. Rev. B 59, 1743–1757 (1999).

    CAS  Article  Google Scholar 

  21. 21

    Altland, A. & Zirnbauer, M. R. Nonstandard symmetry classes in mesoscopic normal-superconducting hybrid structures. Phys. Rev. B 55, 1142–1161 (1997).

    CAS  Article  Google Scholar 

  22. 22

    Mong, R. S. K., Bardarson, J. H. & Moore, J. E. Quantum transport and two-parameter scaling at the surface of a weak topological insulator. Phys. Rev. Lett. 108, 076804 (2012).

    Article  Google Scholar 

  23. 23

    Ringel, Z., Kraus, Y. & Stern, A. The strong side of weak topological insulators. Phys. Rev. B 86, 045102 (2012).

    Article  Google Scholar 

  24. 24

    Ruck, M. Bi13Pt3I7: Ein Subiodid mit einer pseudosymmetrischen Schichtstruktur. Z. Anorg. Allg. Chem. 623, 1535 (1997).

    CAS  Article  Google Scholar 

  25. 25

    Ruck, M. From the metal to the molecule—ternary bismuth subhalides. Angew. Chem. Int. Ed. 40, 1182–1193 (2001).

    CAS  Article  Google Scholar 

  26. 26

    Borisenko, S. V. One-cubed ARPES user facility at BESSY II. Synchrotron Radiat. News 25, 6–11 (2012).

    Article  Google Scholar 

Download references


We acknowledge the help of S. Thirupathaiah, T. Kim and J. Maletz at the ARPES beamline and the grants: BO 1912/3-1, BO 1912/2-2 and ZA 654/1-1. We thank M. Kaiser and A. Gerisch for contributions in solving the crystal structure. We are indebted to ZIH TU Dresden for the provided computational facilities.

Author information




B.R. and M. Ruck. planned and carried out the material synthesis and X-ray analysis. S.B., V.Z. and B.B. planned and carried out the ARPES experiments. S.B. prepared the samples and analysed the ARPES data. J.v.d.B., C.O. and M. Richter developed the theory with A.I., B.R., K.K. and M. Richter performing the band-structure calculations and K.K. implementing the calculation of topological invariants into the FPLO code. A.I. analysed the chemical bonding. J.v.d.B. and M. Ruck wrote the paper with contributions from all co-authors. M. Ruck, B.B. and J.v.d.B. supervised the project.

Corresponding author

Correspondence to Jeroen van den Brink.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 587 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Rasche, B., Isaeva, A., Ruck, M. et al. Stacked topological insulator built from bismuth-based graphene sheet analogues. Nature Mater 12, 422–425 (2013).

Download citation

Further reading


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