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.

  • Letter
  • Published:

Strong interplay between stripe spin fluctuations, nematicity and superconductivity in FeSe

An Erratum to this article was published on 22 January 2016

This article has been updated


In iron-based superconductors the interactions driving the nematic order (that breaks four-fold rotational symmetry in the iron plane) may also mediate the Cooper pairing1. The experimental determination of these interactions, which are believed to depend on the orbital or the spin degrees of freedom1,2,3,4, is challenging because nematic order occurs at, or slightly above, the ordering temperature of a stripe magnetic phase1,5. Here, we study FeSe (ref. 6)—which exhibits a nematic (orthorhombic) phase transition at Ts = 90 K without antiferromagnetic ordering—by neutron scattering, finding substantial stripe spin fluctuations coupled with the nematicity that are enhanced abruptly on cooling through Ts. A sharp spin resonance develops in the superconducting state, whose energy (4 meV) is consistent with an electron–boson coupling mode revealed by scanning tunnelling spectroscopy7. The magnetic spectral weight in FeSe is found to be comparable to that of the iron arsenides8,9. Our results support recent theoretical proposals that both nematicity and superconductivity are driven by spin fluctuations1,10,11,12,13.

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

Access options

Buy this article

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

Figure 1: Orthorhombic crystal structure, magnetic susceptibility, χ, and resistivity, ρ, of FeSe single crystal.
Figure 2: Structure phase transition and momentum dependence of the spin fluctuations at various temperatures in FeSe.
Figure 3: Energy dependence of spin fluctuations for FeSe in the superconducting state (T = 1.5 K) and normal state (T = 11 and 110 K).
Figure 4: Temperature dependence of spin fluctuations in FeSe.

Similar content being viewed by others

Change history

  • 15 December 2015

    In the original version of this Letter published online, the x axis of Fig. 2a was labelled incorrectly. In addition, tick labels have been added to the x axes of Fig. 2b and Fig. 2d. This has been corrected in all versions of the Letter.


  1. Fernandes, R. M., Chubukov, A. V. & Schmalian, J. What drives nematic order in iron-based superconductors? Nature Phys. 10, 97–104 (2014).

    Article  CAS  Google Scholar 

  2. Fang, C., Yao, H., Tsai, W.-F., Hu, J. & Kivelson, S. A. Theory of electron nematic order in LaFeAsO. Phys. Rev. B 77, 224509 (2008).

    Article  Google Scholar 

  3. Xu, C., Muller, M. & Sachdev, S. Ising and spin orders in the iron-based superconductors. Phys. Rev. B 78, 020501(R) (2008).

    Article  Google Scholar 

  4. Kruger, F., Kumar, S., Zaanen, J. & van den Brink, J. Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors. Phys. Rev. B 79, 054504 (2009).

    Article  Google Scholar 

  5. Dai, P. C., Hu, J. P. & Dagotto, E. Magnetism and its microscopic origin in iron-based high-temperature superconductors. Nature Phys. 8, 709–718 (2012).

    Article  CAS  Google Scholar 

  6. McQueen, T. M. et al. Tetragonal-to-orthorhombic structural phase transition at 90 K in the superconductor Fe1.01Se. Phys. Rev. Lett. 103, 057002 (2009).

    Article  CAS  Google Scholar 

  7. Song, C. L. et al. Imaging the electron–boson coupling in superconducting FeSe films using a scanning tunneling microscope. Phys. Rev. Lett. 112, 057002 (2014).

    Article  Google Scholar 

  8. Inosov, D. S. et al. Normal-state spin dynamics and temperature-dependent spin-resonance energy in optimally doped BaFe1.85Co0.15As2 . Nature Phys. 6, 178–181 (2010).

    Article  CAS  Google Scholar 

  9. Zhao, J. et al. Effect of electron correlations on magnetic excitations in the isovalently doped iron-based superconductor Ba(Fe1−xRux)2As2 . Phys. Rev. Lett. 110, 147003 (2013).

    Article  Google Scholar 

  10. Wang, F., Kivelson, S. & Lee, D. H. Nematicity and quantum paramagnetism in FeSe. Nature Phys. 11, 959–963 (2015).

    Article  CAS  Google Scholar 

  11. Glasbrenner, J. K. et al. Effect of magnetic frustration on nematicity and superconductivity in iron chalcogenides. Nature Phys. 11, 953–958 (2015).

    Article  CAS  Google Scholar 

  12. Yu, R. & Si, Q. M. Antiferroquadrupolar and Ising-nematic orders of a frustrated bilinear-biquadratic Heisenberg model and implications for the magnetism of FeSe. Phys. Rev. Lett. 115, 116401 (2015).

    Article  Google Scholar 

  13. Scalapino, D. J. A common thread: The pairing interaction for unconventional superconductors. Rev. Mod. Phys. 84, 1383 (2012).

    Article  CAS  Google Scholar 

  14. Chuang, T.-M. et al. Nematic electronic structure in the “parent” state of the iron-based superconductor Ca(Fe1−xCox)2 As2 . Science 327, 181–184 (2010).

    Article  CAS  Google Scholar 

  15. Lu, X. Y. et al. Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe2−xNixAs2 . Science 345, 657–660 (2014).

    Article  CAS  Google Scholar 

  16. Yi, M. et al. Symmetry-breaking orbital anisotropy observed for detwinned Ba(Fe1−xCox)2As2 above the spin density wave transition. Proc. Natl Acad. Sci. USA 108, 6878–6883 (2011).

    Article  CAS  Google Scholar 

  17. Chu, J.-H., Kuo, H.-H., Analytis, J. G. & Fisher, I. R. Divergent nematic susceptibility in an iron arsenide superconductor. Science 337, 710–712 (2012).

    Article  CAS  Google Scholar 

  18. Zhang, Q. et al. Neutron-scattering measurements of the spin excitations in LaFeAsO and Ba(Fe0.953Co0.047)2As2: Evidence for a sharp enhancement of spin fluctuations by nematic order. Phys. Rev. Lett. 114, 057001 (2015).

    Article  Google Scholar 

  19. Kontani, H. & Onari, S. Orbital-fluctuation-mediated superconductivity in iron pnictides: Analysis of the five-orbital Hubbard–Holstein model. Phys. Rev. Lett. 104, 157001 (2010).

    Article  Google Scholar 

  20. Medvedev, S. et al. Electronic and magnetic phase diagram of β-Fe1.01Se with superconductivity at 36.7 K under pressure. Nature Mater. 8, 630–633 (2009).

    Article  CAS  Google Scholar 

  21. Guo, J. G. et al. Superconductivity in the iron selenide KxFe2Se2(0 ≤ x ≤ 1.0). Phys. Rev. B 82, 180520(R) (2010).

    Article  Google Scholar 

  22. Ge, J.-F. et al. Superconductivity above 100 K in single-layer FeSe films on doped SrTiO3 . Nature Mater. 14, 285–289 (2015).

    Article  CAS  Google Scholar 

  23. Böhmer, A. E. et al. Origin of the tetragonal-to-orthorhombic phase transition in FeSe: A combined thermodynamic and NMR study of nematicity. Phys. Rev. Lett. 114, 027001 (2015).

    Article  Google Scholar 

  24. Baek, S.-H. et al. Orbital-driven nematicity in FeSe. Nature Mater. 14, 210–214 (2015).

    Article  CAS  Google Scholar 

  25. Xu, Z. J. et al. Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen via inelastic neutron scattering. Phys. Rev. B 84, 052506 (2011).

    Article  Google Scholar 

  26. Qiu, Y. M. et al. Spin gap and resonance at the nesting wave vector in superconducting FeSe0.4Te0.6 . Phys. Rev. Lett. 103, 067008 (2009).

    Article  Google Scholar 

  27. Kasahara, S. et al. Field-induced superconducting phase of FeSe in the BCS-BEC cross-over. Proc. Natl Acad. Sci. USA 111, 16309–16313 (2014).

    Article  CAS  Google Scholar 

  28. Zhang, C. L. et al. Distinguishing s± and s++ electron pairing symmetries by neutron spin resonance in superconducting NaFe0.935Co0.045As. Phys. Rev. B 88, 064504 (2013).

    Article  Google Scholar 

  29. Park, J. T. et al. Magnetic resonant mode in the low-energy spin-excitation spectrum of superconducting Rb2Fe4Se5 single crystals. Phys. Rev. Lett. 107, 177005 (2011).

    Article  CAS  Google Scholar 

  30. Chareev, D. et al. Single crystal growth and characterization of tetragonal FeSe1−x superconductors. Cryst. Eng. Commun. 15, 1989–1993 (2013).

    Article  CAS  Google Scholar 

  31. Ma, M. W. et al. Flux-free growth of large superconducting crystal of FeSe by traveling-solvent floatingzone technique. Supercond. Sci. Technol. 27, 122001 (2014).

    Article  Google Scholar 

  32. Hsu, F. C. et al. Superconductivity in the PbO-type structure α-FeSe. Proc. Natl Acad. Sci. USA 105, 14262–14264 (2008).

    Article  CAS  Google Scholar 

  33. Rahn, M. C. et al. Strong (π, 0) spin fluctuations in β-FeSe observed by neutron spectroscopy. Phys. Rev. B 91, 180501 (2015).

    Article  Google Scholar 

Download references


We thank D. H. Lee, Q. Si, F. Wang and H. Yao for useful discussions. This work is supported by the National Natural Science Foundation of China (Grant No. 11374059), the Ministry of Science and Technology of China (973 project: 2015CB921302) and the Shanghai Pujiang Scholar Program (Grant No. 13PJ1401100). M.M. and F.Z. acknowledge support from the National Natural Science Foundation of China (Grant No. 11190020). H.C. received support from the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. A.N.V. was supported in part by the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST 〈MISiS〉 (No. 2-2014-036). D.A.C. and A.N.V. also acknowledge the support of the Russian Foundation for Basic Research through Grants 13-02-00174, 14-02-92002, 14-02-92693.

Author information

Authors and Affiliations



J.Z. planned the project. M.M., F.Z., D.A.C. and A.N.V. synthesized the sample. Q.W., Y. Shen, B.P., Y.H., M.A.-H. and X.C. characterized the sample. Q.W. and Y. Shen. carried out the neutron experiments with experimental assistance from P.S., K.S., T.R.F., P.B., Y. Sidis and H.C. J.Z. and Q.W. analysed the data and wrote the paper. All authors provided comments for the paper.

Corresponding author

Correspondence to Jun Zhao.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1096 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, Q., Shen, Y., Pan, B. et al. Strong interplay between stripe spin fluctuations, nematicity and superconductivity in FeSe. Nature Mater 15, 159–163 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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