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.

  • Perspective
  • Published:

Nematicity and nematic fluctuations in iron-based superconductors

Nature Physics volume 18, pages 1412–1419 (2022)Cite this article

Subjects

Abstract

The spontaneous reduction of rotational symmetry in a crystalline solid driven by an electronic mechanism is referred to as electronic nematicity. This phenomenon—initially thought to be rare—has now been observed in an increasing number of strongly interacting systems. In particular, the ubiquitous presence of nematicity in a number of unconventional superconductors suggests its importance in developing a unified understanding of their intricate phase diagrams and superconducting pairing. In this regard, the iron-based superconductors present an ideal material platform to study electronic nematicity. Their nematic transition is pronounced, it can be studied with a wide range of experimental techniques, it is easily tunable, and high-quality samples are widely available. Signatures of nematic quantum criticality near optimal dopings have been reported in almost all families of iron-based superconductors. Here we highlight how the nematic phase in this class of materials can be addressed in its full complexity, encompassing momentum-, time-, energy- and material-dependences. We also discuss a number of important open questions that pertain to how nematicity affects the superconducting pairing and normal-state properties, and intriguing quantum-critical behaviour near the nematic transition.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Fig. 1: Schematic of nematicity manifested in iron-pnictide superconductors.
Fig. 2: Signatures of nematicity in experimental probes.
Fig. 3: Nematic susceptibility and material diversity.

Similar content being viewed by others

References

  1. Fradkin, E., Kivelson, S. A., Lawler, M. J., Eisenstein, J. P. & Mackenzie, A. P. Nematic Fermi fluids in condensed matter physics. Annu. Rev. Condens. Matter Phys. 1, 153–178 (2010).

    Article  ADS  Google Scholar 

  2. Lilly, M. P., Cooper, K. B., Eisenstein, J. P., Pfeiffer, L. N. & West, K. W. Evidence for an anisotropic state of two-dimensional electrons in high Landau levels. Phys. Rev. Lett. 82, 394–397 (1999).

    Article  ADS  Google Scholar 

  3. Borzi, R. A. et al. Formation of a nematic fluid at high fields in Sr3Ru2O7. Science 315, 214–217 (2007).

    Article  ADS  Google Scholar 

  4. Lester, C. et al. Field-tunable spin-density-wave phases in Sr3Ru2O7. Nat. Mater. 14, 373–378 (2015).

    Article  ADS  Google Scholar 

  5. Hinkov, V. et al. Electronic liquid crystal state in the high-temperature superconductor YBa2Cu3O6.45. Science 319, 597–600 (2008).

    Article  Google Scholar 

  6. de la Cruz, C. et al. Magnetic order close to superconductivity in the iron-based layered LaO1 − xFxFeAs systems. Nature 453, 899–902 (2008).

    Article  ADS  Google Scholar 

  7. Nomura, T. et al. Crystallographic phase transition and high-Tc superconductivity in LaFeAsO:F. Superconductor Sci. Technol. 21, 125028 (2008).

    Article  ADS  Google Scholar 

  8. Fernandes, R. M. et al. Effects of nematic fluctuations on the elastic properties of iron arsenide superconductors. Phys. Rev. Lett. 105, 157003 (2010).

    Article  ADS  Google Scholar 

  9. Nandi, S. et al. Anomalous suppression of the orthorhombic lattice distortion in superconducting Ba(Fe1–xCox)2 As2 single crystals. Phys. Rev. Lett. 104, 057006 (2010).

    Article  ADS  Google Scholar 

  10. 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  ADS  Google Scholar 

  11. Chu, J.-H. et al. In-plane resistivity anisotropy in an underdoped iron arsenide superconductor. Science 329, 824–826 (2010).

    Article  ADS  Google Scholar 

  12. Dusza, A. et al. Anisotropic charge dynamics in detwinned Ba(Fe1–xCox)2As2. Europhys. Lett. 93, 37002 (2011).

    Article  ADS  Google Scholar 

  13. Fu, M. et al. NMR search for the spin nematic state in a LaFeAsO single crystal. Phys. Rev. Lett. 109, 247001 (2012).

    Article  ADS  Google Scholar 

  14. Jiang, S., Jeevan, H. S., Dong, J. & Gegenwart, P. Thermopower as a sensitive probe of electronic nematicity in iron pnictides. Phys. Rev. Lett. 110, 067001 (2013).

    Article  ADS  Google Scholar 

  15. Chuang, T.-M. et al. Nematic Electronic Structure in the ‘Parent’ State of the Iron-Based Superconductor Ca(Fe1–xCox)2As2. Science 327, 181–184 (2010).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  17. Lu, X. et al. Spin-excitation anisotropy in the nematic state of detwinned FeSe. Nat. Phys. 18, 806–812 (2021).

    Article  Google Scholar 

  18. Kasahara, S. et al. Electronic nematicity above the structural and superconducting transition in BaFe2(As1 − xP2)2. Nature 486, 382–385 (2012).

    Article  ADS  Google Scholar 

  19. Rosenthal, E. P. et al. Visualization of electron nematicity and unidirectional antiferroic fluctuations at high temperatures in NaFeAs. Nat. Phys. 10, 225–232 (2014).

    Article  Google Scholar 

  20. Wiecki, P. et al. NMR evidence for static local nematicity and its cooperative interplay with low-energy magnetic fluctuations in FeSe under pressure. Phys. Rev. B 96, 180502 (2017).

    Article  ADS  Google Scholar 

  21. Thewalt, E. et al. Imaging anomalous nematic order and strain in optimally doped BaFe2(As,P)2. Phys. Rev. Lett. 121, 027001 (2018).

    Article  ADS  Google Scholar 

  22. Shimojima, T. et al. Discovery of mesoscopic nematicity wave in iron-based superconductors. Science 373, 1122–1125 (2021).

    Article  ADS  Google Scholar 

  23. Lahiri, A., Klein, A. & Fernandes, R. M. Defect-induced electronic smectic state at the surface of nematic materials. Phys. Rev. B 106, L140503 (2021).

    Article  Google Scholar 

  24. 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  ADS  Google Scholar 

  25. Zhang, Y. et al. Symmetry breaking via orbital-dependent reconstruction of electronic structure in detwinned NaFeAs. Phys. Rev. B 85, 085121 (2012).

    Article  ADS  Google Scholar 

  26. Suzuki, Y. et al. Momentum-dependent sign inversion of orbital order in superconducting FeSe. Phys. Rev. B 92, 205117 (2015).

    Article  ADS  Google Scholar 

  27. Zhang, Y. et al. Distinctive orbital anisotropy observed in the nematic state of a FeSe thin film. Phys. Rev. B 94, 115153 (2016).

    Article  ADS  Google Scholar 

  28. Pfau, H. et al. Momentum dependence of the nematic order parameter in iron-based superconductors. Phys. Rev. Lett. 123, 066402 (2019).

    Article  ADS  Google Scholar 

  29. Watson, M. D. et al. Evidence for unidirectional nematic bond ordering in FeSe. Phys. Rev. B 94, 201107 (2016).

    Article  ADS  Google Scholar 

  30. Yi, M. et al. The nematic energy scale and the missing electron pocket in FeSe. Phys. Rev. X 9, 041049 (2019).

    Google Scholar 

  31. Rhodes, L. C., Eschrig, M., Kim, T. K. & Watson, M. D. FeSe and the missing electron pocket problem. Front. Phys. 10, 859017 (2022).

    Article  Google Scholar 

  32. Yi, M. et al. Dynamic competition between spin–density wave order and superconductivity in underdoped Ba1 − xKxFe2As2. Nat. Commun. 5, 3711 (2014).

    Article  ADS  Google Scholar 

  33. Tanatar, M. A. et al. Uniaxial-strain mechanical detwinning of CaFe2As2 and BaFe2As2 crystals: optical and transport study. Phys. Rev. B 81, 184508 (2010).

    Article  ADS  Google Scholar 

  34. Kuo, H.-H., Chu, J.-H., Palmstrom, J. C., Kivelson, S. A. & Fisher, I. R. Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors. Science 352, 958–962 (2016).

    Article  MathSciNet  MATH  ADS  Google Scholar 

  35. Böhmer, A. E. et al. Nematic susceptibility of hole-doped and electron-doped BaFe2As2 iron-based superconductors from shear modulus measurements. Phys. Rev. Lett. 112, 047001 (2014).

    Article  ADS  Google Scholar 

  36. Böhmer, A. E. & Meingast, C. Electronic nematic susceptibility of iron-based superconductors. Comptes Rendus Phys. 17, 90–112 (2016).

    Article  Google Scholar 

  37. Gallais, Y. & Paul, I. Charge nematicity and electronic Raman scattering in iron-based superconductors. Comptes Rendus Phys. 17, 113–139 (2016).

    Article  ADS  Google Scholar 

  38. Chen, X., Maiti, S., Fernandes, R. M. & Hirschfeld, P. J. Nematicity and superconductivity: competition versus cooperation. Phys. Rev. B 102, 184512 (2020).

    Article  ADS  Google Scholar 

  39. Edelberg, D., Kumar, H., Shenoy, V., Ochoa, H. & Pasupathy, A. N. Tunable strain soliton networks confine electrons in van der Waals materials. Nat. Phys. 16, 1097–1102 (2020).

    Article  Google Scholar 

  40. Kissikov, T. et al. Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe2As2. Nat. Commun. 9, 1058 (2018).

    Article  ADS  Google Scholar 

  41. Caglieris, F. et al. Strain derivative of thermoelectric properties as a sensitive probe for nematicity. npj Quantum Mater. 6, 27 (2021).

    Article  ADS  Google Scholar 

  42. Sanchez, J. J. et al. The transport–structural correspondence across the nematic phase transition probed by elasto X-ray diffraction. Nat. Mater. 20, 1519–1524 (2021).

    Article  ADS  Google Scholar 

  43. Ikeda, M. S. et al. Elastocaloric signature of nematic fluctuations. Proc. Natl Acad. Sci. USA 118, e2105911118 (2021).

    Article  Google Scholar 

  44. Hosoi, S. et al. Nematic quantum critical point without magnetism in FeSe1 − xSx superconductors. Proc. Natl Acad. Sci. USA 113, 8139–8143 (2016).

    Article  ADS  Google Scholar 

  45. Hong, X. et al. Evolution of the nematic susceptibility in LaFe1 − xCoxAsO. Phys. Rev. Lett. 125, 067001 (2020).

    Article  ADS  Google Scholar 

  46. Ishida, K. et al. Pure nematic quantum critical point accompanied by a superconducting dome. Proc. Natl Acad. Sci. USA 119, e2110501119 (2022).

    Article  Google Scholar 

  47. Worasaran, T. et al. Nematic quantum criticality in an Fe-based superconductor revealed by strain-tuning. Science 372, 973–977 (2021).

    Article  Google Scholar 

  48. Metzner, W., Rohe, D. & Andergassen, S. Soft Fermi surfaces and breakdown of Fermi-liquid behavior. Phys. Rev. Lett. 91, 066402 (2003).

    Article  ADS  Google Scholar 

  49. Lederer, S., Schattner, Y., Berg, E. & Kivelson, S. A. Enhancement of superconductivity near a nematic quantum critical point. Phys. Rev. Lett. 114, 097001 (2015).

    Article  ADS  Google Scholar 

  50. Yamase, H. & Zeyher, R. Superconductivity from orbital nematic fluctuations. Phys. Rev. B 88, 180502 (2013).

    Article  ADS  Google Scholar 

  51. Maier, T. A. & Scalapino, D. J. Pairing interaction near a nematic quantum critical point of a three-band CuO2 model. Phys. Rev. B 90, 174510 (2014).

    Article  ADS  Google Scholar 

  52. Metlitski, M. A., Mross, D. F., Sachdev, S. & Senthil, T. Cooper pairing in non-Fermi liquids. Phys. Rev. B 91, 115111 (2015).

    Article  ADS  Google Scholar 

  53. Lederer, S., Schattner, Y., Berg, E. & Kivelson, S. A. Superconductivity and non-Fermi liquid behavior near a nematic quantum critical point. Proc. Natl Acad. Sci. USA 114, 4905–4910 (2017).

    Article  ADS  Google Scholar 

  54. Labat, D. & Paul, I. Pairing instability near a lattice-influenced nematic quantum critical point. Phys. Rev. B 96, 195146 (2017).

    Article  ADS  Google Scholar 

  55. Chubukov, A. V., Abanov, A., Wang, Y. & Wu, Y.-M. The interplay between superconductivity and non-Fermi liquid at a quantum-critical point in a metal. Ann. Phys. 417, 168142 (2020).

    Article  MathSciNet  Google Scholar 

  56. Lawler, M. J., Barci, D. G., Fernández, V., Fradkin, E. & Oxman, L. Nonperturbative behavior of the quantum phase transition to a nematic Fermi fluid. Phys. Rev. B 73, 085101 (2006).

    Article  ADS  Google Scholar 

  57. Metlitski, M. A. & Sachdev, S. Quantum phase transitions of metals in two spatial dimensions. I. Ising-nematic order. Phys. Rev. B 82, 075127 (2010).

    Article  ADS  Google Scholar 

  58. Mross, D. F., McGreevy, J., Liu, H. & Senthil, T. Controlled expansion for certain non-Fermi-liquid metals. Phys. Rev. B 82, 045121 (2010).

    Article  ADS  Google Scholar 

  59. Lee, W.-C. & Phillips, P. W. Non-Fermi liquid due to orbital fluctuations in iron pnictide superconductors. Phys. Rev. B 86, 245113 (2012).

    Article  ADS  Google Scholar 

  60. Fitzpatrick, A. L., Kachru, S., Kaplan, J. & Raghu, S. Non-Fermi-liquid fixed point in a Wilsonian theory of quantum critical metals. Phys. Rev. B 88, 125116 (2013).

    Article  ADS  Google Scholar 

  61. Dalidovich, D. & Lee, S.-S. Perturbative non-Fermi liquids from dimensional regularization. Phys. Rev. B 88, 245106 (2013).

    Article  ADS  Google Scholar 

  62. Shibauchi, T., Carrington, A. & Matsuda, Y. A quantum critical point lying beneath the superconducting dome in iron pnictides. Annu. Rev. Condens. Matter Phys. 5, 113–135 (2014).

    Article  ADS  Google Scholar 

  63. Analytis, J. G. et al. Transport near a quantum critical point in BaFe2(As1–xPx)2. Nat. Phys. 10, 194–197 (2014).

    Article  Google Scholar 

  64. Licciardello, S. et al. Electrical resistivity across a nematic quantum critical point. Nature 567, 213–217 (2019).

    Article  ADS  Google Scholar 

  65. Shimojima, T. et al. Ultrafast nematic-orbital excitation in FeSe. Nat. Commun. 10, 1946 (2019).

    Article  ADS  Google Scholar 

  66. 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  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  68. Wang, Q. et al. Strong interplay between stripe spin fluctuations, nematicity and superconductivity in FeSe. Nat. Mater. 15, 159–163 (2016).

    Article  ADS  Google Scholar 

  69. Böhmer, A. E. & Kreisel, A. Nematicity, magnetism and superconductivity in FeSe. J. Phys. Condens. Matter 30, 023001 (2018).

    Article  ADS  Google Scholar 

  70. Lee, C.-C., Yin, W.-G. & Ku, W. Ferro-orbital order and strong magnetic anisotropy in the parent compounds of iron-pnictide superconductors. Phys. Rev. Lett. 103, 267001 (2009).

    Article  ADS  Google Scholar 

  71. Onari, S. & Kontani, H. Self-consistent vertex correction analysis for iron-based superconductors: mechanism of coulomb interaction-driven orbital fluctuations. Phys. Rev. Lett. 109, 137001 (2012).

    Article  ADS  Google Scholar 

  72. Gastiasoro, M. N., Paul, I., Wang, Y., Hirschfeld, P. J. & Andersen, B. M. Emergent defect states as a source of resistivity anisotropy in the nematic phase of iron pnictides. Phys. Rev. Lett. 113, 127001 (2014).

    Article  ADS  Google Scholar 

  73. Fernandes, R. M., Abrahams, E. & Schmalian, J. Anisotropic in-plane resistivity in the nematic phase of the iron pnictides. Phys. Rev. Lett. 107, 217002 (2011).

    Article  ADS  Google Scholar 

  74. Valenzuela, B., Bascones, E. & Calderón, M. J. Conductivity anisotropy in the antiferromagnetic state of iron pnictides. Phys. Rev. Lett. 105, 207202 (2010).

    Article  ADS  Google Scholar 

  75. de Carvalho, V. S. & Fernandes, R. M. Resistivity near a nematic quantum critical point: impact of acoustic phonons. Phys. Rev. B 100, 115103 (2019).

    Article  ADS  Google Scholar 

  76. Kuo, H. & Fisher, I. R. Effect of disorder on the resistivity anisotropy near the electronic nematic phase transition in pure and electron-doped BaFe2As2. Phys. Rev. Lett. 112, 227001 (2014).

    Article  ADS  Google Scholar 

  77. Tanatar, M. A. et al. Origin of the resistivity anisotropy in the nematic phase of FeSe. Phys. Rev. Lett. 117, 127001 (2016).

    Article  ADS  Google Scholar 

  78. Mirri, C. et al. Origin of the resistive anisotropy in the electronic nematic phase of BaFe2As2 revealed by optical spectroscopy. Phys. Rev. Lett. 115, 107001 (2015).

    Article  ADS  Google Scholar 

  79. Malinowski, P. et al. Suppression of superconductivity by anisotropic strain near a nematic quantum critical point. Nat. Phys. 16, 1189–1193 (2020).

    Article  Google Scholar 

  80. Wang, L. et al. Superconductivity-enhanced nematicity and ‘s + d’ gap symmetry in Fe(Se1–xSx). Phys. Status Solidi b 254, 1600153 (2017).

    Article  ADS  Google Scholar 

  81. Sprau, P. O. et al. Discovery of orbital-selective Cooper pairing in FeSe. Science 357, 75–80 (2017).

    Article  ADS  Google Scholar 

  82. Hanaguri, T. et al. Two distinct superconducting pairing states divided by the nematic end point in FeSe1–xSx. Sci. Adv. 4, eaar6419 (2018).

    Article  ADS  Google Scholar 

  83. Paul, I. & Garst, M. Lattice effects on nematic quantum criticality in metals. Phys. Rev. Lett. 118, 227601 (2017).

    Article  ADS  Google Scholar 

  84. Reiss, P., Graf, D., Haghighirad, A. A., Vojta, T. & Coldea, A. I. Signatures of a quantum Griffiths phase close to an electronic nematic quantum phase transition. Phys. Rev. Lett. 127, 246402 (2021).

    Article  ADS  Google Scholar 

  85. Rosenberg, E. W., Chu, J.-H., Ruff, J. P. C., Hristov, A. T. & Fisher, I. R. Divergence of the quadrupole-strain susceptibility of the electronic nematic system YbRu2Ge2. Proc. Natl Acad. Sci. USA 116, 7232–7237 (2019).

    Article  ADS  Google Scholar 

  86. Cao, Y. et al. Nematicity and competing orders in superconducting magic-angle graphene. Science 372, 264–271 (2021).

    Article  ADS  Google Scholar 

  87. Yonezawa, S. Nematic superconductivity in doped Bi2Se3 topological superconductors. Condens. Matter 4, 2 (2019).

    Article  Google Scholar 

  88. Kohama, Y. et al. Possible observation of quantum spin-nematic phase in a frustrated magnet. Proc. Natl Acad. Sci. USA 116, 10686–10690 (2019).

    Article  ADS  Google Scholar 

  89. Seo, S. et al. Nematic state in CeAuSb2. Phys. Rev. X 10, 011035 (2020).

    Google Scholar 

  90. Eckberg, C. et al. Sixfold enhancement of superconductivity in a tunable electronic nematic system. Nat. Phys. 16, 346–350 (2020).

    Article  Google Scholar 

  91. Chibani, S. et al. Lattice-shifted nematic quantum critical point in FeSe1–xSx. npj Quantum Mater. 6, 37 (2020).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We would like to thank I. Fisher and Q. Si for valuable comments and A. Kreyssig for critical and helpful reading of this manuscript. A.E.B. acknowledges support from the German Research Foundation (DFG) under CRC/TRR 288 (Project A02) and from the Helmholtz Association under contract no. VH-NG-1242. J.H.C. acknowledges the support of the Gordon and Betty Moore Foundation’s EPiQS Initiative, grant no. GBMF6759 to J.-H.C., the David and Lucile Packard Foundation, and the US Air Force Office of Scientific Research under grant no. FA9550-21-1-0068. S.L. is supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Systems Accelerator (QSA). M.Y. acknowledges support from the US Department of Energy grant no. DE-SC0021421, the Robert A. Welch Foundation grant no. C-2024, and the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant no. GBMF9470.

Author information

Authors and Affiliations

  1. Institute for Experimental Physics IV, Ruhr-Universität Bochum, Bochum, Germany

    Anna E. Böhmer

  2. Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, Karlsruhe, Germany

    Anna E. Böhmer

  3. Department of Physics, University of Washington, Seattle, WA, USA

    Jiun-Haw Chu

  4. University of California, Berkeley, CA, USA

    Samuel Lederer

  5. Department of Physics and Astronomy, Rice University, Houston, TX, USA

    Ming Yi

Authors
  1. Anna E. Böhmer
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jiun-Haw Chu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Samuel Lederer
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Ming Yi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Anna E. Böhmer.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Physics thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

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

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Böhmer, A.E., Chu, JH., Lederer, S. et al. Nematicity and nematic fluctuations in iron-based superconductors. Nat. Phys. 18, 1412–1419 (2022). https://doi.org/10.1038/s41567-022-01833-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41567-022-01833-3

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