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Nematic transition and nanoscale suppression of superconductivity in Fe(Te,Se)

Abstract

The interplay of different electronic phases underlies the physics of unconventional superconductors. One of the most intriguing examples is a high-temperature superconductor, FeTe1 – xSex (refs. 1,2,3,4,5,6,7,8,9,10,11). This superconductor undergoes both a topological transition3,4, linked to the electronic band inversion, and an electronic nematic phase transition, associated with rotation symmetry breaking, around the same Se composition where the superconducting transition temperature peaks12,13. In this regime, nematic fluctuations and symmetry-breaking strain could be important, but this is yet to be fully explored. Using spectroscopic-imaging scanning tunnelling microscopy, we study the electronic nematic transition in FeTe1 – xSex as a function of composition. Near the critical Se composition, we find electronic nematicity in nanoscale regions. The superconducting coherence peaks are suppressed in areas where static nematic order is the strongest. By analysing atomic displacement in scanning tunnelling microscopy topographs, we find that small anisotropic strain can give rise to these strongly nematic localized regions. Our experiments reveal a tendency of FeTe1 – xSex, near x ≈ 0.45, to form puddles hosting static nematic order, suggestive of nematic fluctuations pinned by structural inhomogeneity, and demonstrate the effect of anisotropic strain on superconductivity in this regime.

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Data availability

Data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request. Source data are provided with this paper.

Code availability

The computer code used for data analysis is available upon request from the corresponding author.

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Acknowledgements

I.Z. gratefully acknowledges support from Army Research Office grant W911NF-17-1-0399 (STM experiments) and National Science Foundation grant NSF-DMR-1654041 (strain analysis). The work at Brookhaven was supported by the Office of Basic Energy Sciences, US Department of Energy (DOE) under contract DE-SC0012704. Support was provided via the UC Santa Barbara NSF Quantum Foundry funded under the Q-AMASE-i initiative under award DMR-1906325 (S.D.W. and J.H.). L.D. was supported by the Materials Research Science and Engineering Centers (MRSEC) programme of the National Science Foundation through grant no. DMR-1720256 (Seed Program). Z.W. acknowledges support from US Department of Energy, Basic Energy Sciences grant DE-FG02-99ER45747. The work in Zhejiang University is supported by the National Key R&D Program of China under grant 2016YFA0300402 and the National Natural Science Foundation of China (grants NSFC-12074335 and 11974095).

Author information

Authors

Contributions

STM experiments were carried out by H.Z. and H.L. L.D., B.X., J.S. and R.Z. grew the Fe(Te,Se) single crystals, supervised by M.F., G.G., J.H. and S.D.W. H.Z. and H.L. analysed the STM data with guidance from I.Z. Z.W. provided theoretical input on the interpretation of STM data. I.Z., Z.W., H.Z. and S.D.W. wrote the manuscript with input from all the authors. I.Z. supervised the project.

Corresponding author

Correspondence to Ilija Zeljkovic.

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The authors declare no competing interests.

Peer review information Nature Physics thanks Milan Allan, Michael Lawler and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Discussions 1–8, Tables 1 and 2, Figs. 1–16 and references 1–5.

Source data

Source Data Fig. 3

Raw data for Fig. 3b,c,g,h,l,m.

Source Data Fig. 4

Raw data for Fig. 4f.

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Zhao, H., Li, H., Dong, L. et al. Nematic transition and nanoscale suppression of superconductivity in Fe(Te,Se). Nat. Phys. 17, 903–908 (2021). https://doi.org/10.1038/s41567-021-01254-8

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• DOI: https://doi.org/10.1038/s41567-021-01254-8

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