Novel Relationship between Antiferromagnetic Spin Fluctuations and Superconductivity in FeSe0.47Te0.53 under Pressure

ORAL

Abstract

The relationship between antiferromagnetic spin fluctuations, nematic fluctuations, and superconductivity has been central to understanding the pairing mechanism in iron-based superconductors. Iron chalcogenides, which hold the simplest crystal structure in iron-based superconductors, provide a good platform to investigate the relationship. Here, we report 77Se and 125Te nuclear magnetic resonance studies of FeSe0.47Te0.53, which is close to a pure nematic quantum critical point. Both the superconducting critical temperature and antiferromagnetic spin fluctuations were found to be enhanced under pressure, which suggests a correlation between superconductivity and antiferromagnetic spin fluctuations in FeSe0.47Te0.53. However, the contribution of antiferromagnetic spin fluctuations to superconductivity in FeSe0.47Te0.53 is much less compared to that in FeSe1−xSx [1]. Since superconductivity in FeSe1−xSx was widely believed to be mediated by antiferromagnetic spin fluctuations, the contrasting behavior of FeSe0.47Te0.53 should come from a different origin. Our study indicates that instead of antiferromagnetic spin fluctuations, nematic fluctuations play a dominant role in the superconductivity in FeSe1−xTex.

[1] K. Rana, D. V. Ambika, S. L. Bud'ko, A. E. Böhmer, P. C. Canfield, and Y. Furukawa, Phys. Rev. B 107, 134507 (2023).

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Presenters

  • Qing-Ping Ding

    Ames National Laboratory, Ames National Laboratory, U.S.DOE

Authors

  • Qing-Ping Ding

    Ames National Laboratory, Ames National Laboratory, U.S.DOE

  • Juan Schmidt

    Ames National Laboratory, Ames National Laboratory, and Department of Physics and Astronomy, Iowa State University

  • Jose A Moreno

    Laboratorio de Bajas Temperaturas y Altos Campos Magneticos, Departamento de Física de la Materia Condensada, Universidad Autonoma de Madrid, Department of Physics, La Universidad Autónoma de Madrid

  • Sergey L Bud'ko

    Iowa State University, Ames National Laboratory, and Department of Physics and Astronomy, Iowa State University, Ames National Laboratory and Iowa State University

  • Paul C Canfield

    Iowa State University, Ames National Laboratory, and Department of Physics and Astronomy, Iowa State University, Ames National Laboratory and Iowa State University

  • Yuji Furukawa

    Iowa State University, Ames National Laboratory, and Department of Physics and Astronomy, Iowa State University, Ames National Laboratory, Iowa State University