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arXiv · 1512.04074

Nodal Superconducting Gap in $\beta$-FeS

Jie Xing·Hai Lin·Yufeng Li·Sheng Li·Xiyu Zhu·Huan Yang·Hai-Hu Wen
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Abstract

Low temperature specific heat has been measured in superconductor $\beta$-FeS with T$_c$ = 4.55 K. It is found that the low temperature electronic specific heat C$_e$/T can be fitted to a linear relation in the low temperature region, but fails to be described by an exponential relation as expected by an s-wave gap. We try fittings to the data with different gap structures and find that a model with one or two nodal gaps can fit the data. Under a magnetic field, the field induced specific heat $\Delta\gamma$=[C$_e$(H)-C$_e$(0)]/T shows the Volovik relation $\Delta\gamma_e(H)\propto \sqrt{H}$, suggesting the presence of nodal gap(s) in this material.

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Jie Xing, Hai Lin, Yufeng Li, Sheng Li, Xiyu Zhu, Huan Yang, Hai-Hu Wen. 2015-12-13. Nodal Superconducting Gap in $\beta$-FeS. https://doi.org/10.1103/physrevb.93.104520

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