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.

Electric-field control of spin–orbit torque in a magnetically doped topological insulator


Electric-field manipulation of magnetic order has proved of both fundamental and technological importance in spintronic devices. So far, electric-field control of ferromagnetism, magnetization and magnetic anisotropy has been explored in various magnetic materials, but the efficient electric-field control of spin–orbit torque (SOT) still remains elusive. Here, we report the effective electric-field control of a giant SOT in a Cr-doped topological insulator (TI) thin film using a top-gate field-effect transistor structure. The SOT strength can be modulated by a factor of four within the accessible gate voltage range, and it shows strong correlation with the spin-polarized surface current in the film. Furthermore, we demonstrate the magnetization switching by scanning gate voltage with constant current and in-plane magnetic field applied in the film. The effective electric-field control of SOT and the giant spin-torque efficiency in Cr-doped TI may lead to the development of energy-efficient gate-controlled spin-torque devices compatible with modern field-effect semiconductor technologies.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Current-induced magnetization switching and second harmonic measurements in the Al2O3(20 nm)/Cr-TI(7 nm)/GaAs(substrate) structure device.
Figure 2: Top-gate Hall bar configuration and gate electric-field effect on material properties in the Au(electrode)/Al2O3(20 nm)/Cr-TI(7 nm)/GaAs(substrate) structure device.
Figure 3: Second harmonic measurements under different gate voltages and voltage-induced magnetization switching behaviours.
Figure 4: Correlations between the surface carrier densities, surface currents, surface band structures and the measured electric-field control of SOT in the top-gate Hall bar device.


  1. 1

    Ohno, H. et al. Electric-field control of ferromagnetism. Nature 408, 944–946 (2000).

    CAS  Article  Google Scholar 

  2. 2

    Chiba, D., Yamanouchi, M., Matsukura, F. & Ohno, H. Electrical manipulation of magnetization reversal in a ferromagnetic semiconductor. Science 301, 943–945 (2003).

    CAS  Article  Google Scholar 

  3. 3

    Tokura, Y. Multiferroics as quantum electromagnets. Science 312, 1481–1482 (2006).

    CAS  Article  Google Scholar 

  4. 4

    Eerenstein, W., Mathur, N. D. & Scott, J. F. Multiferroic and magnetoelectric materials. Nature 442, 759–765 (2006).

    CAS  Article  Google Scholar 

  5. 5

    Heron, J. T. et al. Deterministic switching of ferromagnetism at room temperature using an electric field. Nature 516, 370–373 (2014).

    CAS  Article  Google Scholar 

  6. 6

    Maruyama, T. et al. Large voltage-induced magnetic anisotropy change in a few atomic layers of iron. Nature Nanotech. 4, 158–161 (2009).

    CAS  Article  Google Scholar 

  7. 7

    Amiri, P. K. & Wang, K. L. Voltage-controlled magnetic anisotropy in spintronic devices. Spin 2, 1240002 (2012).

    Article  Google Scholar 

  8. 8

    Ralph, D. C. & Stiles, M. D. Spin transfer torques. J. Magn. Magn. Mater. 320, 1190–1216 (2008).

    CAS  Article  Google Scholar 

  9. 9

    Garello, K. et al. Symmetry and magnitude of spin-orbit torques in ferromagnetic heterostructures. Nature Nanotech. 8, 587–593 (2013).

    CAS  Article  Google Scholar 

  10. 10

    Liu, R. H., Lim, W. L. & Urazhdin, S. Control of current-induced spin-orbit effects in a ferromagnetic heterostructure by electric field. Phys. Rev. B 89, 220409 (2014).

    Article  Google Scholar 

  11. 11

    Bauer, U. et al. Magneto-ionic control of interfacial magnetism. Nature Mater. 14, 174–181 (2015).

    CAS  Article  Google Scholar 

  12. 12

    Qi, X.-L. & Zhang, S.-C. Topological insulators and superconductors. Rev. Mod. Phys. 83, 1057–1110 (2011).

    CAS  Article  Google Scholar 

  13. 13

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

    CAS  Article  Google Scholar 

  14. 14

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

    CAS  Article  Google Scholar 

  15. 15

    Fan, Y. et al. Magnetization switching through giant spin-orbit torque in a magnetically doped topological insulator heterostructure. Nature Mater. 13, 699–704 (2014).

    CAS  Article  Google Scholar 

  16. 16

    Mellnik, A. R. et al. Spin-transfer torque generated by a topological insulator. Nature 511, 449–451 (2014).

    CAS  Article  Google Scholar 

  17. 17

    Wang, Y. et al. Topological surface states originated spin-orbit torques in Bi2Se3 . Phys. Rev. Lett. 114, 257202 (2015).

    Article  Google Scholar 

  18. 18

    Liu, L. et al. Spin-torque switching with the giant spin Hall effect of tantalum. Science 336, 555–558 (2012).

    CAS  Article  Google Scholar 

  19. 19

    Liu, L., Lee, O. J., Gudmundsen, T. J., Ralph, D. C. & Buhrman, R. A. Current-induced switching of perpendicularly magnetized magnetic layers using spin torque from the spin Hall effect. Phys. Rev. Lett. 109, 096602 (2012).

    Article  Google Scholar 

  20. 20

    Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. Nature 476, 189–193 (2011).

    CAS  Article  Google Scholar 

  21. 21

    Miron, I. M. et al. Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer. Nature Mater. 9, 230–234 (2010).

    Article  Google Scholar 

  22. 22

    Liu, L., Moriyama, T., Ralph, D. C. & Buhrman, R. A. Spin-torque ferromagnetic resonance induced by the spin Hall effect. Phys. Rev. Lett. 106, 036601 (2011).

    Article  Google Scholar 

  23. 23

    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 

  24. 24

    Yazyev, O. 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 

  25. 25

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

    CAS  Article  Google Scholar 

  26. 26

    Li, C. H. et al. Electrical detection of charge-current-induced spin polarization due to spin-momentum locking in Bi2Se3 . Nature Nanotech. 9, 218–224 (2014).

    CAS  Article  Google Scholar 

  27. 27

    Tang, J. et al. Electrical detection of spin-polarized surface states conduction in (Bi0.53Sb0.47)2Te3 topological insulator. Nano Lett. 14, 5423–5429 (2014).

    CAS  Article  Google Scholar 

  28. 28

    Ando, Y. et al. Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi1.5Sb0.5Te1.7Se1.3 . Nano Lett. 14, 6226–6230 (2014).

    CAS  Article  Google Scholar 

  29. 29

    Liu, L. et al. Spin-polarized tunneling study of spin-momentum locking in topological insulators. Phys. Rev. B 91, 235437 (2015).

    Article  Google Scholar 

  30. 30

    Tian, J. et al. Topological insulator based spin valve devices: evidence for spin polarized transport of spin-momentum-locked topological surface states. Solid State Commun. 191, 1–5 (2014).

    CAS  Article  Google Scholar 

  31. 31

    Fischer, M. H., Vaezi, A., Manchon, A. & Kim, E.-A. Large spin torque in topological insulator/ferromagnetic metal bilayers. Preprint at (2013).

  32. 32

    Tserkovnyak, Y. & Bender, S. A. Spin Hall phenomenology of magnetic dynamics. Phys. Rev. B 90, 014428 (2014).

    Article  Google Scholar 

  33. 33

    Shiomi, Y. et al. Spin-electricity conversion induced by spin injection into topological insulators. Phys. Rev. Lett. 113, 196601 (2014).

    CAS  Article  Google Scholar 

  34. 34

    Deorani, P. et al. Observation of inverse spin Hall effect in bismuth selenide. Phys. Rev. B 90, 094403 (2014).

    Article  Google Scholar 

  35. 35

    Jamali, M. et al. Giant spin pumping and inverse spin Hall effect in the presence of surface and bulk spin-orbit coupling of topological insulator Bi2Se3 . Nano Lett. 15, 7126–7132 (2015).

    CAS  Article  Google Scholar 

  36. 36

    Baker, A. A., Figueroa, A. I., Collins-McIntyre, L. J., van der Laan, G. & Hesjedal, T. Spin pumping in ferromagnet-topological insulator-ferromagnet heterostructures. Sci. Rep. 5, 7907 (2015).

    CAS  Article  Google Scholar 

  37. 37

    Kou, X. et al. Manipulating surface-related ferromagnetism in modulation-doped topological insulators. Nano Lett. 13, 4587–4593 (2013).

    CAS  Article  Google Scholar 

  38. 38

    Kou, X. et al. Interplay between different magnetisms in Cr-doped topological insulators. ACS Nano 7, 9205–9212 (2013).

    CAS  Article  Google Scholar 

  39. 39

    Lang, M. et al. Competing weak localization and weak antilocalization in ultrathin topological insulators. Nano Lett. 13, 48–53 (2013).

    CAS  Article  Google Scholar 

  40. 40

    Kim, J. et al. Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO. Nature Mater. 12, 240–245 (2013).

    CAS  Article  Google Scholar 

  41. 41

    Lang, M. et al. Revelation of topological surface states in Bi2Se3 thin films by in situ al passivation. ACS Nano 6, 295–302 (2012).

    CAS  Article  Google Scholar 

  42. 42

    Checkelsky, J. G., Ye, J., Onose, Y., Iwasa, Y. & Tokura, Y. Dirac-fermion-mediated ferromagnetism in a topological insulator. Nature Phys. 8, 729–733 (2012).

    CAS  Article  Google Scholar 

  43. 43

    Skinner, B., Chen, T. & Shklovskii, B. I. Why is the bulk resistivity of topological insulators so small? Phys. Rev. Lett. 109, 176801 (2012).

    Article  Google Scholar 

  44. 44

    He, L. et al. Evidence of the two surface states of (Bi0.53Sb0.47)2Te3 films grown by van der Waals epitaxy. Sci. Rep. 3, 3406 (2013).

    Article  Google Scholar 

  45. 45

    Kong, D. et al. Ambipolar field effect in the ternary topological insulator (BixSb1-x)2Te3 by composition tuning. Nature Nanotech. 6, 705–709 (2011).

    CAS  Article  Google Scholar 

  46. 46

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

    Article  Google Scholar 

  47. 47

    Nagaosa, N., Sinova, J., Onoda, S., MacDonald, A. H. & Ong, N. P. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).

    Article  Google Scholar 

  48. 48

    Wang, J., Lian, B. & Zhang, S.-C. Electrically tunable magnetism in magnetic topological insulators. Phys. Rev. Lett. 115, 036805 (2015).

    Article  Google Scholar 

  49. 49

    Zhang, W., Yu, R., Zhang, H.-J., Dai, X. & Fang, Z. First-principles studies of the three-dimensional strong topological insulators Bi2Te3, Bi2Se3 and Sb2Te3 . New J. Phys. 12, 065013 (2010).

    Article  Google Scholar 

  50. 50

    Lang, M. et al. Proximity induced high-temperature magnetic order in topological insulator - ferrimagnetic insulator heterostructure. Nano Lett. 14, 3459–3465 (2014).

    CAS  Article  Google Scholar 

Download references


The material growth and characterizations were supported by the DARPA Meso program under contract No.N66001-12-1-4034 and N66001-11-1-4105. The device fabrication and low temperature measurements were supported as part of the Spins and Heat in Nanoscale Electronic Systems (SHINES), an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award # DE-SC0012670. The analysis and theoretical modelling were supported by the US Army Research Office under grants W911NF-14-1-0607 and W911NF-15-1-0561. We are also very grateful to the support from the FAME Center, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA. Y.W. thanks the support of the National 973 Program of China (2013CB934600), National Science Foundation of China (11174244, 51390474) and Zhejiang Provincial Natural Science Foundation of China (LR12A04002).

Author information




Y.F., X.K., P.U. and K.L.W. conceived and designed the research. X.K. and L.P. grew the material. M.L. and X.C. fabricated the Hall bar devices. Y.F. and Q.S. performed the measurements. X.K., P.U., L.P., M.L., X.C., J.T., M.M., K.M., L-T.C., M.A., G.Y., T.N. and K.W. contributed to the measurements and analysis. J.L. and Y.W. performed structural analysis. Y.F., P.U. and Y.T. designed the theoretical model. Y.F., X.K., P.U. and K.L.W. wrote the paper with the help from all of the other co-authors.

Corresponding authors

Correspondence to Yabin Fan or Kang L. Wang.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 3229 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Fan, Y., Kou, X., Upadhyaya, P. et al. Electric-field control of spin–orbit torque in a magnetically doped topological insulator. Nature Nanotech 11, 352–359 (2016).

Download citation

Further reading


Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research