Electrical detection of charge-current-induced spin polarization due to spin-momentum locking in Bi2Se3


Topological insulators exhibit metallic surface states populated by massless Dirac fermions with spin-momentum locking, where the carrier spin lies in-plane, locked at right angles to the carrier momentum. Here, we show that a charge current produces a net spin polarization via spin-momentum locking in Bi2Se3 films, and this polarization is directly manifested as a voltage on a ferromagnetic contact. This voltage is proportional to the projection of the spin polarization onto the contact magnetization, is determined by the direction and magnitude of the charge current, scales inversely with Bi2Se3 film thickness, and its sign is that expected from spin-momentum locking rather than Rashba effects. Similar data are obtained for two different ferromagnetic contacts, demonstrating that these behaviours are independent of the details of the ferromagnetic contact. These results demonstrate direct electrical access to the topological insulators’ surface-state spin system and enable utilization of its remarkable properties for future technological applications.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Schematic of TI surface bands and experimental concept.
Figure 2: Schematic of contacts and transport devices.
Figure 3: TI spin polarization detected as a voltage with Fe/Al2O3 contacts.
Figure 4: TI spin polarization detected as a voltage with Fe/Al2O3 and Co/MgO/graphene contacts.
Figure 5: Dependence of the ferromagnetic detector voltage on bias current, thickness and temperature.


  1. 1

    Moore, J. E. The birth of topological insulators. Nature 464, 194–198 (2010).

    CAS  Article  Google Scholar 

  2. 2

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

    CAS  Article  Google Scholar 

  3. 3

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

    Article  Google Scholar 

  4. 4

    Hsieh, D. et al. A topological Dirac insulator in a quantum spin Hall phase. Nature 452, 970–975 (2008).

    CAS  Article  Google Scholar 

  5. 5

    Kong, D. & Cui, Y. Opportunities in chemistry and materials science for topological insulators and their nanostructures. Nature Chem. 3, 845–849 (2011).

    CAS  Article  Google Scholar 

  6. 6

    Zutic, I., Fabian, J. & Das Sarma, S. Spintronics: fundamentals and applications. Rev. Mod. Phys. 76, 323–410 (2004).

    CAS  Article  Google Scholar 

  7. 7

    Dery, H., Dalal, P., Cywinski, L. & Sham, L. J. Spin-based logic in semiconductors for reconfigurable large-scale circuits. Nature 447, 573–576 (2007).

    CAS  Article  Google Scholar 

  8. 8

    Pesin, D. & MacDonald, A. H. Spintronics and pseudospintronics in graphene and topological insulators. Nature Mater. 11, 409–416 (2012).

    CAS  Article  Google Scholar 

  9. 9

    Nayak, C. et al. Non-abelian anyons and topological quantum computation. Rev. Mod. Phys. 80, 1083–1159 (2008).

    CAS  Article  Google Scholar 

  10. 10

    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 

  11. 11

    Qi, X-L., Li, R., Zang, J. & Zhang, S-C. Inducing a magnetic monopole with topological surface states. Science 323, 1184–1187 (2009).

    CAS  Article  Google Scholar 

  12. 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. 13

    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  Article  Google Scholar 

  14. 14

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

    CAS  Article  Google Scholar 

  15. 15

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

    CAS  Article  Google Scholar 

  16. 16

    Burkov, A. A. & Hawthorn, D. G. Spin and charge transport on the surface of a topological insulator. Phys. Rev. Lett. 105, 066802 (2010).

    CAS  Article  Google Scholar 

  17. 17

    Culcer, D., Hwang, E. H., Stanescu, T. D. & Das Sarma, S. Two-dimensional surface charge transport in topological insulators. Phys. Rev. B 82, 155457 (2010).

    Article  Google Scholar 

  18. 18

    Yazyev, V., Moore, J. E. & Louie, S. G. Spin polarization and transport of surface states in the topological insulators Bi2Se3 and Bi2Te3 from first principles. Phys. Rev. Lett. 105, 266806 (2010).

    Article  Google Scholar 

  19. 19

    Kuroda, K. et al. Hexagonally deformed Fermi surface of the 3D topological insulator Bi2Se3 . Phys. Rev. Lett. 105, 076802 (2010).

    CAS  Article  Google Scholar 

  20. 20

    Souma, S. et al. Direct measurement of the out-of-plane spin texture in the Dirac-cone surface state of a topological insulator. Phys. Rev. Lett. 106, 216803 (2011).

    CAS  Article  Google Scholar 

  21. 21

    Pan, Z-H. et al. Electronic structure of the topological insulator Bi2Se3 using angle-resolved photoemission spectroscopy: evidence for a nearly full surface spin polarization. Phys. Rev. Lett. 106, 257004 (2011).

    Article  Google Scholar 

  22. 22

    McIver, J. W., Hsieh, D., Steinberg, H., Jarillo-Herrero, P. & Gedik, N. Control over topological insulator photocurrents with light polarization. Nature Nanotech. 7, 96–100 (2012).

    CAS  Article  Google Scholar 

  23. 23

    Pan, Z-H. et al. Measurement of an exceptionally weak electron–phonon coupling on the surfaces of the toplogical insulator Bi2Se3 using angle-resolved photoemission. Phys. Rev. Lett. 108, 187001 (2012).

    Article  Google Scholar 

  24. 24

    Valla, T., Pan, Z-H., Gardner, D., Lee, Y. S. & Chu, S. Photoemission spectroscopy of magnetic and nonmagnetic impurities on the surface of the Bi2Se3 topological insulator. Phys. Rev. Lett. 108, 117601 (2012).

    CAS  Article  Google Scholar 

  25. 25

    Scholz, M. R. et al. Tolerance of topological surface states towards magnetic moments: Fe on Bi2Se3 . Phys. Rev. Lett. 108, 256810 (2012).

    CAS  Article  Google Scholar 

  26. 26

    Ji, H. et al. Bulk intergrowth of a topological insulator with a room temperature ferromagnet. Phys. Rev. B 85, 165313 (2012).

    Article  Google Scholar 

  27. 27

    Xu, S-Y. et al. Hedgehog spin texture and Berry's phase tuning in a magnetic topological insulator. Nature Phys. 8, 616–622 (2012).

    CAS  Article  Google Scholar 

  28. 28

    Silsbee, R. H. Spin–orbit induced coupling of charge current and spin polarization. J. Phys. Condens. Matter 16, R179–R207 (2004).

    CAS  Article  Google Scholar 

  29. 29

    Hong, S., Diep, V., Datta, S. & Chen, Y. P. Modeling potentiometric measurements in topological insulators including parallel channels. Phys. Rev. B 86, 085131 (2012).

    Article  Google Scholar 

  30. 30

    Lou, X. et al. Electrical detection of spin transport in lateral ferromagnet–semiconductor devices. Nature Phys. 3, 197–202 (2007).

    CAS  Article  Google Scholar 

  31. 31

    Tombros, N., Jozsa, C., Popinciuc, M., Jonkman, H. T. & van Wees, B. J. Electronic spin transport and spin precession in single graphene layers at room temperature. Nature 448, 571–574 (2007).

    CAS  Article  Google Scholar 

  32. 32

    Hammar, P. R. & Johnson, M. Spin-dependent current transmission across a ferromagnet-insulator-two-dimensional electron gas junction. Appl. Phys. Lett. 79, 2591–2593 (2001).

    CAS  Article  Google Scholar 

  33. 33

    Liu, Y., Weinert, M. & Li, L. Spiral growth without dislocations: molecular beam epitaxy of the topological insulator Bi2Se3 on epitaxial graphene/SiC(0001). Phys. Rev. Lett. 108, 115501 (2012).

    CAS  Article  Google Scholar 

  34. 34

    Liu, Y. et al. Charging Dirac states at anti-phase domain boundaries in the three-dimensional topological insulator Bi2Se3 . Phys. Rev. Lett. 110, 186804 (2013).

    CAS  Article  Google Scholar 

  35. 35

    Qi, Y., Rhim, S. H., Sun, G. F., Weinert, M. & Li, L. Epitaxial graphene on SiC(0001): more than just honeycombs. Phys. Rev. Lett. 105, 085502 (2010).

    CAS  Article  Google Scholar 

  36. 36

    Li, H. D. et al. The van der Waals epitaxy of Bi2Se3 on the vicinal Si(111) surface: an approach for preparing high-quality thin films of a topological insulator. New J. Phys. 12, 103038 (2010).

    Article  Google Scholar 

  37. 37

    Johnson, M. & Silsbee, R. H. Interfacial charge-spin coupling: injection and detection of spin magnetization in metals. Phys. Rev. Lett. 55, 1790–1793 (1985).

    CAS  Article  Google Scholar 

  38. 38

    Jedema, F. J., Heersche, H. B., Filip, A. T., Baselmans, J. J. A. & van Wees, B. J. Electrical detection of spin precession in a metallic mesoscopic spin valve. Nature 416, 713–716 (2002).

    CAS  Article  Google Scholar 

  39. 39

    Van 't Erve, O. M. J. et al. Electrical injection and detection of spin-polarized carriers in silicon in a lateral transport geometry. Appl. Phys. Lett. 91, 212109 (2007).

    Article  Google Scholar 

  40. 40

    Sasaki, T. et al. Electrical spin injection into silicon using MgO tunnel barrier. Appl. Phys. Express 2, 053003 (2009).

    Article  Google Scholar 

  41. 41

    Cobas, E., Friedman, A. L., van ‘t Erve, O. M. J., Robinson, J. T. & Jonker, B. T. Graphene as a tunnel barrier: graphene-based magnetic tunnel junctions. Nano Lett. 12, 3000–3004 (2012).

    CAS  Article  Google Scholar 

  42. 42

    Van 't Erve, O. M. J. et al. Low-resistance spin injection into silicon using graphene tunnel barriers. Nature Nanotech. 7, 737–742 (2012).

    CAS  Article  Google Scholar 

  43. 43

    Chen, S. et al. Oxidation resistance of graphene-coated Cu and Cu/Ni alloy. ACS Nano 5, 1321–1327 (2011).

    CAS  Article  Google Scholar 

  44. 44

    Li, X. et al. Large-area graphene single crystals grown by low-pressure chemical vapor deposition of methane on copper. J. Am. Chem. Soc. 133, 2816–2819 (2011).

    CAS  Article  Google Scholar 

Download references


The authors acknowledge support for this work from core programmes at the Naval Research Laboratory, and the Office of Naval Research contract N0001413WX21513.

Author information




C.H.L., L.L. and B.T.J. conceived and designed the experiments. Y.L. and L.L. grew the Bi2Se3 films. J.T.R. provided the large-area graphene. C.H.L. fabricated the devices and performed the transport measurements with assistance from O.M.J.E. C.H.L., O.M.J.E. and B.T.J. analysed the data. B.T.J. and C.H.L. wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to C. H. Li or B. T. Jonker.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary Information (PDF 1042 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Li, C., van ‘t Erve, O., Robinson, J. et al. Electrical detection of charge-current-induced spin polarization due to spin-momentum locking in Bi2Se3. Nature Nanotech 9, 218–224 (2014). https://doi.org/10.1038/nnano.2014.16

Download citation

Further reading