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

ABSTRACT 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 through

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CONTENT BEING VIEWED BY OTHERS FIELD-FREE SPIN-ORBIT TORQUE SWITCHING ASSISTED BY IN-PLANE UNCONVENTIONAL SPIN TORQUE IN ULTRATHIN [PT/CO]N Article Open access 04 July 2023 NONVOLATILE

MAGNETIZATION SWITCHING IN A SINGLE-LAYER MAGNETIC TOPOLOGICAL INSULATOR Article Open access 21 August 2023 GENERATION OF OUT-OF-PLANE POLARIZED SPIN CURRENT BY NON-UNIFORM OXYGEN OCTAHEDRAL

TILT/ROTATION Article Open access 24 August 2024 REFERENCES * Ohno, H. et al. Electric-field control of ferromagnetism. _Nature_ 408, 944–946 (2000). Article  CAS  Google Scholar  * Chiba,

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

Scholar  * Tokura, Y. Multiferroics as quantum electromagnets. _Science_ 312, 1481–1482 (2006). Article  CAS  Google Scholar  * Eerenstein, W., Mathur, N. D. & Scott, J. F. Multiferroic

and magnetoelectric materials. _Nature_ 442, 759–765 (2006). Article  CAS  Google Scholar  * Heron, J. T. et al. Deterministic switching of ferromagnetism at room temperature using an

electric field. _Nature_ 516, 370–373 (2014). Article  CAS  Google Scholar  * Maruyama, T. et al. Large voltage-induced magnetic anisotropy change in a few atomic layers of iron. _Nature

Nanotech_. 4, 158–161 (2009). Article  CAS  Google Scholar  * Amiri, P. K. & Wang, K. L. Voltage-controlled magnetic anisotropy in spintronic devices. _Spin_ 2, 1240002 (2012). Article 

Google Scholar  * Ralph, D. C. & Stiles, M. D. Spin transfer torques. _J. Magn. Magn. Mater_. 320, 1190–1216 (2008). Article  CAS  Google Scholar  * Garello, K. et al. Symmetry and

magnitude of spin-orbit torques in ferromagnetic heterostructures. _Nature Nanotech_. 8, 587–593 (2013). Article  CAS  Google Scholar  * 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  * Bauer, U. et al. Magneto-ionic control

of interfacial magnetism. _Nature Mater_. 14, 174–181 (2015). Article  CAS  Google Scholar  * Qi, X.-L. & Zhang, S.-C. Topological insulators and superconductors. _Rev. Mod. Phys_. 83,

1057–1110 (2011). Article  CAS  Google Scholar  * Hasan, M. Z. & Kane, C. L. Colloquium: topological insulators. _Rev. Mod. Phys_. 82, 3045–3067 (2010). Article  CAS  Google Scholar  *

Moore, J. E. The birth of topological insulators. _Nature_ 464, 194–198 (2010). Article  CAS  Google Scholar  * Fan, Y. et al. Magnetization switching through giant spin-orbit torque in a

magnetically doped topological insulator heterostructure. _Nature Mater_. 13, 699–704 (2014). Article  CAS  Google Scholar  * Mellnik, A. R. et al. Spin-transfer torque generated by a

topological insulator. _Nature_ 511, 449–451 (2014). Article  CAS  Google Scholar  * Wang, Y. et al. Topological surface states originated spin-orbit torques in Bi2Se3 . _Phys. Rev. Lett_.

114, 257202 (2015). Article  Google Scholar  * Liu, L. et al. Spin-torque switching with the giant spin Hall effect of tantalum. _Science_ 336, 555–558 (2012). Article  CAS  Google Scholar 

* 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  * Miron, I. M. et al. Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection.

_Nature_ 476, 189–193 (2011). Article  CAS  Google Scholar  * 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  * 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  * 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).

Article  CAS  Google Scholar  * 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  * Hsieh, D. et al. A tunable topological insulator in the spin helical Dirac transport regime. _Nature_ 460,

1101–1105 (2009). Article  CAS  Google Scholar  * 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). Article  CAS  Google Scholar  * 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). Article  CAS  Google Scholar  * 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). Article  CAS  Google Scholar  * Liu, L. et al. Spin-polarized tunneling study of spin-momentum locking in topological

insulators. _Phys. Rev. B_ 91, 235437 (2015). Article  Google Scholar  * 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). Article  CAS  Google Scholar  * Fischer, M. H., Vaezi, A., Manchon, A. & Kim, E.-A. Large spin

torque in topological insulator/ferromagnetic metal bilayers. Preprint at http://arxiv.org/abs/1305.1328 (2013). * Tserkovnyak, Y. & Bender, S. A. Spin Hall phenomenology of magnetic

dynamics. _Phys. Rev. B_ 90, 014428 (2014). Article  Google Scholar  * Shiomi, Y. et al. Spin-electricity conversion induced by spin injection into topological insulators. _Phys. Rev. Lett_.

113, 196601 (2014). Article  CAS  Google Scholar  * Deorani, P. et al. Observation of inverse spin Hall effect in bismuth selenide. _Phys. Rev. B_ 90, 094403 (2014). Article  Google Scholar

  * 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). Article  CAS  Google Scholar  * 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). Article  CAS  Google Scholar  * Kou, X. et al. Manipulating surface-related ferromagnetism in modulation-doped topological

insulators. _Nano Lett_. 13, 4587–4593 (2013). Article  CAS  Google Scholar  * Kou, X. et al. Interplay between different magnetisms in Cr-doped topological insulators. _ACS Nano_ 7,

9205–9212 (2013). Article  CAS  Google Scholar  * Lang, M. et al. Competing weak localization and weak antilocalization in ultrathin topological insulators. _Nano Lett_. 13, 48–53 (2013).

Article  CAS  Google Scholar  * Kim, J. et al. Layer thickness dependence of the current-induced effective field vector in Ta|CoFeB|MgO. _Nature Mater._ 12, 240–245 (2013). Article  CAS 

Google Scholar  * Lang, M. et al. Revelation of topological surface states in Bi2Se3 thin films by _in situ_ al passivation. _ACS Nano_ 6, 295–302 (2012). Article  CAS  Google Scholar  *

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). Article  CAS  Google

Scholar  * 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  * 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  * Kong, D. et al. Ambipolar

field effect in the ternary topological insulator (BixSb1-x)2Te3 by composition tuning. _Nature Nanotech_. 6, 705–709 (2011). Article  CAS  Google Scholar  * Zhang, J. et al. Band structure

engineering in (Bi1-xSbx)2Te3 ternary topological insulators. _Nature Commun_. 2, 574 (2011). Article  Google Scholar  * 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  * Wang, J., Lian, B. & Zhang, S.-C. Electrically tunable magnetism in magnetic topological

insulators. _Phys. Rev. Lett_. 115, 036805 (2015). Article  Google Scholar  * 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  * Lang, M. et al. Proximity induced high-temperature magnetic order in

topological insulator - ferrimagnetic insulator heterostructure. _Nano Lett_. 14, 3459–3465 (2014). Article  CAS  Google Scholar  Download references ACKNOWLEDGEMENTS 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 Author notes * Yabin Fan, Xufeng Kou and Pramey Upadhyaya: These authors contributed equally to this work AUTHORS AND AFFILIATIONS * Department of Electrical Engineering,

University of California, Los Angeles, 90095, California, USA Yabin Fan, Xufeng Kou, Pramey Upadhyaya, Qiming Shao, Lei Pan, Murong Lang, Xiaoyu Che, Jianshi Tang, Mohammad Montazeri, Koichi

Murata, Li-Te Chang, Mustafa Akyol, Guoqiang Yu, Tianxiao Nie, Kin L. Wong & Kang L. Wang * Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of

Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China Jun Liu & Yong Wang * Department of Physics and Astronomy, University of California, Los Angeles, 90095,

California, USA Yaroslav Tserkovnyak Authors * Yabin Fan View author publications You can also search for this author inPubMed Google Scholar * Xufeng Kou View author publications You can

also search for this author inPubMed Google Scholar * Pramey Upadhyaya View author publications You can also search for this author inPubMed Google Scholar * Qiming Shao View author

publications You can also search for this author inPubMed Google Scholar * Lei Pan View author publications You can also search for this author inPubMed Google Scholar * Murong Lang View

author publications You can also search for this author inPubMed Google Scholar * Xiaoyu Che View author publications You can also search for this author inPubMed Google Scholar * Jianshi

Tang View author publications You can also search for this author inPubMed Google Scholar * Mohammad Montazeri View author publications You can also search for this author inPubMed Google

Scholar * Koichi Murata View author publications You can also search for this author inPubMed Google Scholar * Li-Te Chang View author publications You can also search for this author

inPubMed Google Scholar * Mustafa Akyol View author publications You can also search for this author inPubMed Google Scholar * Guoqiang Yu View author publications You can also search for

this author inPubMed Google Scholar * Tianxiao Nie View author publications You can also search for this author inPubMed Google Scholar * Kin L. Wong View author publications You can also

search for this author inPubMed Google Scholar * Jun Liu View author publications You can also search for this author inPubMed Google Scholar * Yong Wang View author publications You can

also search for this author inPubMed Google Scholar * Yaroslav Tserkovnyak View author publications You can also search for this author inPubMed Google Scholar * Kang L. Wang View author

publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS 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 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).

https://doi.org/10.1038/nnano.2015.294 Download citation * Received: 01 June 2015 * Accepted: 12 November 2015 * Published: 04 January 2016 * Issue Date: April 2016 * DOI:

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