Abstract
Topological insulators are a newly discovered class of materials in which helical conducting modes exist on the surface of a bulk insulator1,2,3,4,5,6. Recently, theoretical works have shown that breaking gauge symmetry7 or time-reversal symmetry8 in these materials produces exotic states that, if realized, represent substantial steps towards realizing new magnetoelectric effects9,10 and tools useful for quantum computing11. Here we demonstrate the latter symmetry breaking in the form of ferromagnetism arising from the interaction between magnetic impurities and the Dirac fermions12,13. Using devices based on cleaved single crystals of Mn-doped Bi2Te3−ySey, the application of both solid-dielectric and ionic-liquid gating allows us to measure the transport response of the surface states within the bulk bandgap in the presence of magnetic ions. By tracking the anomalous Hall effect we find that the surface modes support robust ferromagnetism as well as magnetoconductance that is consistent with enhanced one-dimensional edge-state transport on the magnetic domain wall. Observation of this evidence for quantum transport phenomena demonstrates the accessibility of these exotics states in devices and may serve to focus the wide range of proposed methods for experimentally realizing the quantum anomalous Hall effect8,10 and states required for quantum computing14,15.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to the full article PDF.
USD 39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Kane, C. L. & Mele, E. J. Z2 topological order and the quantum spin Hall effect. Phys. Rev. Lett. 95, 146802 (2005).
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).
Konig, M. et al. Quantum spin Hall insulator state in HgTe quantum wells. Science 318, 766–770 (2007).
Fu, L., Kane, C. L. & Mele, E. J. Topological insulators in three dimensions. Phys. Rev. Lett. 98, 106803 (2007).
Moore, J. E. & Balents, L. Topological invariants of time-reversal-invariant band structures. Phys. Rev. B 75, 121306(R) (2007).
Hsieh, D. et al. A topological Dirac insulator in a quantum spin Hall phase. Nature 452, 970–974 (2008).
Linder, J., Tanaka, Y., Yokoyama, T., Sudbo, A. & Nagaosa, N. Unconventional superconductivity on a topological insulator. Phys. Rev. Lett. 104, 067001 (2010).
Yu, R. et al. Quantized anomalous Hall effect in magnetic topological insulators. Science 329, 61–64 (2010).
Qi, X-L., Hughes, T. L. & Zhang, S-C. Topological field theory of time-reversal invariant insulators. Phys. Rev. B 78, 195424 (2008).
Nomura, K. & Nagaosa, N. Surface-quantized anomalous Hall current and the magnetoelectric effect in magnetically disordered topological insulators. Phys. Rev. Lett. 106, 166802 (2011).
Fu, L. & Kane, C. L. Superconducting proximity effect and Majorana fermions at the surface of a topological insulator. Phys. Rev. Lett. 100, 096407 (2008).
Liu, Q., Liu, C-X., Xu, C., Qi, X-L. & Zhang, S-C. Magnetic impurities on the surface of a topological insulator. Phys. Rev. Lett. 102, 156603 (2009).
Abanin, D. A. & Pesin, D. A. Ordering of magnetic impurities and tunable electronic properties of topological insulators. Phys. Rev. Lett. 106, 136802 (2011).
Fu, L. & Kane, C. L. Probing neutral majorana fermion edge modes with charge transport. Phys. Rev. Lett. 102, 216403 (2009).
Akhmerov, A., Nilsson, J. & Beenakker, C. Electrically detected interferometry of Majorana fermions in a topological insulator. Phys. Rev. Lett. 102, 216404 (2009).
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).
Chen, Y. L. et al. Experimental realization of a three-dimensional topological insulator, Bi2Te3 . Science 325, 178–181 (2009).
Hasan, M. Z. & Kane, C. L. Colloquium: Topological insulators. Rev. Mod. Phys. 82, 3045–3067 (2010).
Chen, Y. L. et al. Massive Dirac fermion on the surface of a magnetically doped topological insulator. Science 329, 659–662 (2010).
Dietl, T., Haury, A. & Merle d’ Aubigne, Y. Free carrier-induced ferromagnetism in structures of diluted magnetic semiconductors. Phys. Rev. B 55, 3347–3350(R) (1997).
Nagaosa, N., Sinova, J., Onoda, S., MacDonald, A. H. & Ong, N. P. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).
Ye, J. T. et al. Liquid-gated interface superconductivity on an atomically flat film. Nature Mater. 9, 125–128 (2010).
Checkelsky, J. G., Hor, Y. S., Cava, R. J. & Ong, N. P. Bulk band gap and surface state conduction observed in voltage-tuned crystals of the topological insulator Bi2Se3 . Phys. Rev. Lett. 106, 196801 (2011).
Choi, J. et al. Single crystal growth and magnetic properties of Mn-doped Bi2Se3 and Sb2Se3 . J. Magn. 9, 125–127 (2004).
Dietl, T., Ohno, H., Matsukura, F., Cibert, J. & Ferrand, D. Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science 287, 1019–1022 (2000).
Ohno, H. et al. Electric-field control of ferromagnetism. Nature 408, 944–946 (2000).
Chiba, D., Matsukura, F. & Ohno, H. Electric-field control of ferromagnetism in (Ga,Mn)As. Appl. Phys. Lett. 89, 162505 (2006).
Kim, D. et al. Surface conduction of topological Dirac electrons in bulk insulating Bi2Se3 . Nature Phys. 8, 460–464 (2012).
Levy, P. M. & Zhang, S. Resistivity due to domain wall scattering. Phys. Rev. Lett. 79, 5110–5113 (1997).
Su, W. P., Schrieffer, J. R. & Heeger, A. J. Solitons in polyacetylene. Phys. Rev. Lett. 42, 1698–1701 (1979).
Acknowledgements
We are grateful to N. Nagaosa, M. Kawasaki, F. Zhang, K. Nomura, B-J. Yang and S. Bahramy for fruitful discussions. This research is supported by the Japan Society for the Promotion of Science through the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program), initiated by the Council for Science and Technology Policy.
Author information
Authors and Affiliations
Contributions
J.G.C. and Y.O. performed the single-crystal growth and experiments. J.G.C. and J.Y. made devices and performed device experiments aided by Y.O. J.G.C. analysed the data and wrote the manuscript with contributions from all authors. Y.I. and Y.T. contributed to discussion of the results and guided the project. Y.T. conceived and coordinated the project.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 912 kb)
Rights and permissions
About this article
Cite this article
Checkelsky, J., Ye, J., Onose, Y. et al. Dirac-fermion-mediated ferromagnetism in a topological insulator. Nature Phys 8, 729–733 (2012). https://doi.org/10.1038/nphys2388
Received:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/nphys2388
This article is cited by
-
Bipolarity of large anomalous Nernst effect in Weyl magnet-based alloy films
Nature Physics (2024)
-
Direct visualization of electronic transport in a quantum anomalous Hall insulator
Nature Materials (2023)
-
Topological phase transitions without symmetry indication in NaZnSb\(_{1-x}\)Bi\(_x\)
Scientific Reports (2022)
-
Enhanced and stable spin Hall conductivity in a disordered time-reversal and inversion symmetry broken topological insulator thin film
Scientific Reports (2022)
-
Investigation on the structural and magnetic properties of MxBi2–xTe3 (M = Gd, Fe, Cr) (x = 0, 1) using colloidal hot-injection method
Bulletin of Materials Science (2022)
