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arXiv · 2011.11475

The Hund's Superconductor Li(Fe,Co)As

H. Miao·Y. L. Wang·J. -X. Yin·J. Zhang·S. Zhang·M. Z. Hasan·R. Yang·X. C. Wang·C. Q. Jin·T. Qian·H. Ding·H. -L. Lee·G. Kotliar
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Abstract

We combine transport, angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy to investigate several low energy manifestations of the Hund coupling in a canonical FeSC family Li(Fe,Co)As. We determine the doping dependence of the coherent-incoherent crossover temperature and the quasi-particle effective mass enhancement in the normal state. Our tunneling spectroscopy result in the superconducting state supports the idea that superconductivity emerging from Hund's metal state displays a universal maximal superconducting gap vs transition temperature (2$\Delta_{max}/k_{B}T_{c}$) value, which is independent of doping level and $T_{c}$.

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H. Miao, Y. L. Wang, J. -X. Yin, J. Zhang, S. Zhang, M. Z. Hasan, R. Yang, X. C. Wang, C. Q. Jin, T. Qian, H. Ding, H. -L. Lee, G. Kotliar. 2020-11-23. The Hund's Superconductor Li(Fe,Co)As. https://doi.org/10.1103/physrevb.103.054503

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