Multiband superconductivity in high pressure sulfur hydrides

G. A. Ummarino; A. Bianconi

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arXiv · 2307.10786

Multiband superconductivity in high pressure sulfur hydrides

G. A. Ummarino·A. Bianconi

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Abstract

The temperature dependence of the two superconducting gaps in pressurised H_3S at 155 GPa with a critical temperature of 203 K has been determined by data analysis of the experimental curve of the upper critical magnetic field as a function of temperature in the framework of the two bands s-wave Eliashberg theory, with two different phonon mediated intra-band Cooper pairing channels in a regime of moderate strong couplings with the key role of the pair exchange interaction between the two gaps giving the two non-diagonal terms of the coupling tensor which are missing in the single band s wave Eliashberg theory. The results provide the prediction of the different temperature dependence of the small and large gaps as a function of temperature which provide evidence of multi-gap superconductivity in H_3S.

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G. A. Ummarino, A. Bianconi. 2023-08-01. Multiband superconductivity in high pressure sulfur hydrides. https://arxiv.org/abs/2307.10786

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