[go: up one dir, main page]
Skip to main content

Thank you for visiting nature.com. 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.

  • Article
  • Published:

Multiple topological states in iron-based superconductors

Nature Physics volume 15, pages 41–47 (2019)Cite this article

Subjects

Abstract

Topological materials and unconventional iron-based superconductors are both important areas of study but, to date, relatively little overlap has been identified between these two fields. However, the combination of topological bands and superconductivity promises the manifestation of exotic superconducting states, including Majorana fermions, the central component of topological quantum computation. Here, using laser-based, spin-resolved and angle-resolved photoemission spectroscopy and density functional theory calculations, we have identified both topological insulator and Dirac semimetal states near the Fermi energy in different iron-based superconducting compounds. Carrier doping can tune these topologically non-trivial bands to the Fermi energy, potentially allowing access to several different superconducting topological states in the same material. These results reveal the generic coexistence of superconductivity and multiple topological states in iron-based superconductors, indicating that this broad class of materials is a promising platform for high-temperature topological superconductivity.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Different topological phases and band structures of iron-based superconductors.
Fig. 2: Electronic structure of Li(Fe,Co)As.
Fig. 3: Spin polarization of the surface Dirac cones from the TI and TDS states in Li(Fe1−xCox)As.
Fig. 4: The TDS bands in Fe(Te,Se) and the linear magnetoresistance.
Fig. 5: Spin polarization of the dyz band in Fe(Te,Se).
Fig. 6: Topological states and the related topological superconductivity.

Similar content being viewed by others

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Kamihara, Y., Watanabe, T., Hirano, M. & Hosono, H. Iron-based layered superconductor La[O1−xFx]FeAs (x = 0.05–0.12) with T c = 26 K. J. Am. Chem. Soc. 130, 3296–3297 (2008).

    Article  Google Scholar 

  2. Johnston, D. C. The puzzle of high temperature superconductivity in layered iron pnictides and chalcogenides. Adv. Phys. 59, 803–1061 (2010).

    Article  ADS  Google Scholar 

  3. Stewart, G. R. Superconductivity in iron compounds. Rev. Mod. Phys. 83, 1589–1652 (2011).

    Article  ADS  Google Scholar 

  4. Hao, N. & Hu, J. Topological phases in the single-layer FeSe. Phys. Rev. X 4, 031053 (2014).

    Google Scholar 

  5. Wang, Z. et al. Topological nature of the FeSe0.5Te0.5 superconductor. Phys. Rev. B 92, 115119 (2015).

    Article  ADS  Google Scholar 

  6. Wu, X., Qin, S., Liang, Y., Fan, H. & Hu, J. Topological characters in Fe(Te1−xSex) thin films. Phys. Rev. B 93, 115129 (2016).

    Article  ADS  Google Scholar 

  7. Xu, G., Lian, B., Tang, P., Qi, X.-L. & Zhang, S.-C. Topological superconductivity on the surface of Fe-based superconductors. Phys. Rev. Lett. 117, 047001 (2016).

    Article  ADS  Google Scholar 

  8. Zhang, P. et al. Observation of topological superconductivity on the surface of an iron-based superconductor. Science 360, 182–186 (2018).

    Article  ADS  Google Scholar 

  9. 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  ADS  Google Scholar 

  10. Mourik, V. et al. Signatures of Majorana fermions in hybrid superconductor–semiconductor nanowire devices. Science 336, 1003–1007 (2012).

    Article  ADS  Google Scholar 

  11. Nadj-Perge, S. et al. Observation of Majorana fermions in ferromagnetic atomic chains on a superconductor. Science 346, 602–607 (2014).

    Article  ADS  Google Scholar 

  12. Albrecht, S. M. et al. Exponential protection of zero modes in Majorana islands. Nature 531, 206–209 (2016).

    Article  ADS  Google Scholar 

  13. Zhang, F., Kane, C. L. & Mele, E. J. Time-reversal-invariant topological superconductivity and Majorana Kramers pairs. Phys. Rev. Lett. 111, 056402 (2013).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  16. Wang, Z. et al. Dirac semimetal and topological phase transitions in A 3Bi (A = Na, K, Rb). Phys. Rev. B 85, 195320 (2012).

    Article  ADS  Google Scholar 

  17. Wang, Z., Weng, H., Wu, Q., Dai, X. & Fang, Z. Three-dimensional Dirac semimetal and quantum transport in Cd3As2. Phys. Rev. B 88, 125427 (2013).

    Article  ADS  Google Scholar 

  18. Liu, Z. K. et al. Discovery of a three-dimensional topological Dirac semimetal, Na3Bi. Science 343, 864–867 (2014).

    Article  ADS  Google Scholar 

  19. Xu, S.-Y. et al. Unconventional transformation of spin Dirac phase across a topological quantum phase transition. Nat. Commun. 6, 6870 (2015).

    Article  Google Scholar 

  20. Neupane, M. et al. Surface versus bulk Dirac state tuning in a three-dimensional topological Dirac semimetal. Phys. Rev. B 91, 241114 (2015).

    Article  ADS  Google Scholar 

  21. Jozwiak, C. et al. Spin-polarized surface resonances accompanying topological surface state formation. Nat. Commun. 7, 13143 (2016).

    Article  ADS  Google Scholar 

  22. Wu, X. et al. CaFeAs2: a staggered intercalation of quantum spin Hall and high-temperature superconductivity. Phys. Rev. B 91, 081111 (2015).

    Article  ADS  Google Scholar 

  23. Shi, X. et al. FeTe1−xSex monolayer films: towards the realization of high-temperature connate topological superconductivity. Sci. Bull. 62, 503–507 (2017).

    Article  Google Scholar 

  24. Wang, X. et al. The superconductivity at 18 K in LiFeAs system. Solid State Commun. 148, 538–540 (2008).

    Article  ADS  Google Scholar 

  25. Borisenko, S. V. et al. Superconductivity without nesting in LiFeAs. Phys. Rev. Lett. 105, 067002 (2010).

    Article  ADS  Google Scholar 

  26. Pitcher, M. J. et al. Compositional control of the superconducting properties of LiFeAs. J. Am. Chem. Soc. 132, 10467–10476 (2010).

    Article  Google Scholar 

  27. Miao, H. et al. Observation of strong electron pairing on bands without Fermi surfaces in LiFe1−xCoxAs. Nat. Commun. 6, 124508 (2015).

    Google Scholar 

  28. Watson, M. D. et al. Three-dimensional electronic structure of the nematic and antiferromagnetic phases of NaFeAs from detwinned angle-resolved photoemission spectroscopy. Phys. Rev. B 97, 035134 (2018).

    Article  ADS  Google Scholar 

  29. Strocov, V. Intrinsic accuracy in 3-dimensional photoemission band mapping. J. Electron. Spectrosc. Relat. Phenom. 130, 65–78 (2003).

    Article  Google Scholar 

  30. Yaji, K. et al. High-resolution three-dimensional spin- and angle-resolved photoelectron spectrometer using vacuum ultraviolet laser light. Rev. Sci. Instrum. 87, 053111 (2016).

    Article  ADS  Google Scholar 

  31. Watson, M. D. et al. Emergence of the nematic electronic state in FeSe. Phys. Rev. B 91, 155106 (2015).

    Article  ADS  Google Scholar 

  32. Zhang, P. et al. Observation of two distinct d xz/d yz band splittings in FeSe. Phys. Rev. B 91, 214503 (2015).

    Article  ADS  Google Scholar 

  33. Liang, T. et al. Ultrahigh mobility and giant magnetoresistance in the Dirac semimetal Cd3As2. Nat. Mater. 14, 280–284 (2014).

    Article  ADS  Google Scholar 

  34. Feng, J. et al. Large linear magnetoresistance in Dirac semimetal Cd3As2 with Fermi surfaces close to the Dirac points. Phys. Rev. B 92, 081306 (2015).

    Article  ADS  Google Scholar 

  35. Abrikosov, A. A. Quantum magnetoresistance. Phys. Rev. B 58, 2788–2794 (1998).

    Article  ADS  Google Scholar 

  36. Richard, P. et al. Observation of Dirac cone electronic dispersion in BaFe2As2. Phys. Rev. Lett. 104, 137001 (2010).

    Article  ADS  Google Scholar 

  37. Tan, S. Y. et al. Observation of Dirac cone band dispersions in FeSe thin films by photoemission spectroscopy. Phys. Rev. B 93, 104513 (2016).

    Article  ADS  Google Scholar 

  38. Miao, H. et al. Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45. Phys. Rev. B 85, 094506 (2012).

    Article  ADS  Google Scholar 

  39. Rinott, S. et al. Tuning across the BCS–BEC crossover in the multiband superconductor Fe1+ySexTe1−x: An angle-resolved photoemission study. Sci. Adv. 3, e1602372 (2017).

    Article  ADS  Google Scholar 

  40. Xu, S.-Y. et al. Observation of Fermi arc surface states in a topological metal. Science 347, 294–298 (2015).

    Article  ADS  Google Scholar 

  41. Wang, D. et al. Evidence for Majorana bound states in an iron-based superconductor. Science https://doi.org/10.1126/science.aao1797 (2018).

  42. Kobayashi, S. & Sato, M. Topological superconductivity in Dirac semimetals. Phys. Rev. Lett. 115, 187001 (2015).

    Article  ADS  Google Scholar 

  43. Hashimoto, T., Kobayashi, S., Tanaka, Y. & Sato, M. Superconductivity in doped Dirac semimetals. Phys. Rev. B 94, 014510 (2016).

    Article  ADS  Google Scholar 

  44. Yang, S. A., Pan, H. & Zhang, F. Dirac and Weyl superconductors in three dimensions. Phys. Rev. Lett. 113, 046401 (2014).

    Article  ADS  Google Scholar 

  45. Aggarwal, L. et al. Unconventional superconductivity at mesoscopic point contacts on the 3D Dirac semimetal Cd3As2. Nat. Mater. 15, 32–37 (2015).

    Article  ADS  Google Scholar 

  46. Wang, H. et al. Observation of superconductivity induced by a point contact on 3D Dirac semimetal Cd3As2 crystals. Nat. Mater. 15, 38–42 (2015).

    Article  ADS  Google Scholar 

  47. He, L. et al. Pressure-induced superconductivity in the three-dimensional topological Dirac semimetal Cd3As2. npj Quant. Mater. 1, 1057 (2016).

    Article  Google Scholar 

  48. Hosur, P., Ghaemi, P., Mong, R. S. K. & Vishwanath, A. Majorana modes at the ends of superconductor vortices in doped topological insulators. Phys. Rev. Lett. 107, 097001 (2011).

    Article  ADS  Google Scholar 

  49. Chiu, C.-K., Ghaemi, P. & Hughes, T. L. Stabilization of Majorana modes in magnetic vortices in the superconducting phase of topological insulators using topologically trivial bands. Phys. Rev. Lett. 109, 237009 (2012).

    Article  ADS  Google Scholar 

  50. Sun, Y. et al. Multiband effects and possible Dirac fermions in Fe1+yTe0.6Se0.4. Phys. Rev. B 89, 144512 (2014).

    Article  ADS  Google Scholar 

  51. Sun, Y., Taen, T., Tsuchiya, Y., Shi, Z. X. & Tamegai, T. Effects of annealing, acid and alcoholic beverages on Fe1+yTe0.6Se0.4. Supercond. Sci. Technol. 26, 015015 (2013).

    Article  ADS  Google Scholar 

  52. Wen, J., Xu, G., Gu, G., Tranquada, J. M. & Birgeneau, R. J. Interplay between magnetism and superconductivity in iron–chalcogenide superconductors: crystal growth and characterizations. Rep. Prog. Phys. 74, 124503 (2011).

    Article  ADS  Google Scholar 

  53. Kresse, G. & Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B 47, 558–561 (1993).

    Article  ADS  Google Scholar 

  54. Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).

    Article  Google Scholar 

  55. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

    Article  ADS  Google Scholar 

  56. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  ADS  Google Scholar 

  57. Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).

    Article  ADS  MathSciNet  Google Scholar 

Download references

Acknowledgements

We acknowledge K. Asakawa, A. Harasawa, Y. Hesagawa, D. Hirai, Z. Hiroi, K. Ishizaka, N. Mitsuishi, M. Sakano and Y. Yoshida for experimental assistance. This work was supported by the Photon and Quantum Basic Research Coordinated Development Program from MEXT, JSPS (KAKENHI Grant Nos. 25220707, JP17H02922, JP16K17755 and 17H01141), the Grants-in-Aid for Scientific Research on Innovative Areas ‘Topological Material Science’, JSPS (grant no. JP15H05855), the Chinese Academy of Sciences (XDB28000000) and the Ministry of Science and Technology of China (2015CB921300). The work in Brookhaven is supported by the Office of Science, US Department of Energy under contract no. DE-SC0012704 and the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science. The work in Würzburg is supported by ERC-StG-TOPOLECTRICS-336012, DFG-SFB 1170 and DFG-SPP 1666.

Author information

Authors and Affiliations

  1. Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan

    Peng Zhang, Koichiro Yaji, Yukiaki Ishida, Yoshimitsu Kohama, Yue Sun, Cedric Bareille, Kenta Kuroda, Takeshi Kondo, Kozo Okazaki, Koichi Kindo & Shik Shin

  2. Department of Physics, Princeton University, Princeton, NJ, USA

    Zhijun Wang

  3. Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg, Würzburg, Germany

    Xianxin Wu & Ronny Thomale

  4. Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China

    Guangyang Dai, Xiancheng Wang, Changqing Jin, Jiangping Hu & Hong Ding

  5. Department of Applied Physics, University of Tokyo, Tokyo, Japan

    Yue Sun & Tsuyoshi Tamegai

  6. CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China

    Jiangping Hu & Hong Ding

  7. Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan

    Kazuki Sumida

  8. Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Japan

    Shilong Wu, Koji Miyamoto & Taichi Okuda

  9. Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA

    G. D. Gu

  10. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan

    Takuto Kawakami & Masatoshi Sato

Authors
  1. Peng Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Zhijun Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Xianxin Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Koichiro Yaji
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Yukiaki Ishida
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Yoshimitsu Kohama
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Guangyang Dai
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Yue Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Cedric Bareille
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Kenta Kuroda
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Takeshi Kondo
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Kozo Okazaki
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Koichi Kindo
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. Xiancheng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  15. Changqing Jin
    View author publications

    You can also search for this author in PubMed Google Scholar

  16. Jiangping Hu
    View author publications

    You can also search for this author in PubMed Google Scholar

  17. Ronny Thomale
    View author publications

    You can also search for this author in PubMed Google Scholar

  18. Kazuki Sumida
    View author publications

    You can also search for this author in PubMed Google Scholar

  19. Shilong Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  20. Koji Miyamoto
    View author publications

    You can also search for this author in PubMed Google Scholar

  21. Taichi Okuda
    View author publications

    You can also search for this author in PubMed Google Scholar

  22. Hong Ding
    View author publications

    You can also search for this author in PubMed Google Scholar

  23. G. D. Gu
    View author publications

    You can also search for this author in PubMed Google Scholar

  24. Tsuyoshi Tamegai
    View author publications

    You can also search for this author in PubMed Google Scholar

  25. Takuto Kawakami
    View author publications

    You can also search for this author in PubMed Google Scholar

  26. Masatoshi Sato
    View author publications

    You can also search for this author in PubMed Google Scholar

  27. Shik Shin
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

P.Z. performed the ARPES measurements on Li(Fe,Co)As and analysed the data with help from K.Y., T. Kondo and S.S.. X. Wu, J.H. and R.T. performed the DFT calculations. G.D., X. Wang and C.J. synthesized the Li(Fe,Co)As samples. P.Z. performed the ARPES measurements on Fe(Te,Se) and analysed the data with help from Y.I., K.Y., C.B., K. Kuroda, T. Kondo, K.O., K.S., S.W., K.M., T.O., H.D. and S.S.. P.Z., Y.K. and K. Kindo performed the magnetoresistance measurements on Fe(Te,Se). Z.W., X.Wu, R.T., T. Kawakami and M.S. performed the theoretical calculations on Fe(Te,Se). G.D.G., Y.S. and T.T. synthesized the Fe(Te,Se) samples. All authors discussed the manuscript. P.Z. and S.S. supervised the whole project.

Corresponding authors

Correspondence to Peng Zhang or Shik Shin.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–8, Supplementary References 1–9, and additional mathematical derivations

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhang, P., Wang, Z., Wu, X. et al. Multiple topological states in iron-based superconductors. Nature Phys 15, 41–47 (2019). https://doi.org/10.1038/s41567-018-0280-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41567-018-0280-z

This article is cited by

Search

Advanced search

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