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arXiv · 2505.11732

Role of Nematic Fluctuations on Superconductivity in FeSe$_{0.47}$Te$_{0.53}$ Revealed by NMR under Pressure

Qing-Ping Ding·Juan Schmidt·Jose A. Moreno·Sergey L. Bud'ko·Paul C. Canfield·Yuji Furukawa
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Abstract

The relationship between antiferromagnetic (AFM) spin fluctuations (SF), nematic fluctuations, and superconductivity (SC) has been central to understanding the pairing mechanism in iron-based superconductors (IBSCs). Iron chalcogenides, which hold the simplest crystal structure in IBSCs, provide a good platform to investigate the relationship. Here, we report $^{77}$Se and $^{125}$Te nuclear magnetic resonance studies of FeSe$_{0.47}$Te$_{0.53}$, which is located close to a nematic quantum critical point (QCP), under pressures up to 1.35 GPa. Both the superconducting critical temperature and AFMSF were found to be enhanced under pressure, which suggests a correlation between SC and AFMSF in FeSe$_{0.47}$Te$_{0.53}$. However, the contribution of AFMSF to SC in FeSe$_{0.47}$Te$_{0.53}$ was found to be much less compared to that in FeSe$_{1-x}$S$_{x}$, suggesting that nematic fluctuations play a dominant role in the SC in FeSe$_{1-x}$Te$_{x}$ around the nematic QCP.

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Qing-Ping Ding, Juan Schmidt, Jose A. Moreno, Sergey L. Bud'ko, Paul C. Canfield, Yuji Furukawa. 2025-05-16. Role of Nematic Fluctuations on Superconductivity in FeSe$_{0.47}$Te$_{0.53}$ Revealed by NMR under Pressure. https://arxiv.org/abs/2505.11732

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