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Novel Relationship between Antiferromagnetic Spin Fluctuations and Superconductivity in FeSe<sub>0.47</sub>Te<sub>0.53</sub> 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