Superconducting gap of H<sub>3</sub>S measured by tunnelling spectroscopy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40269154.
- Also identified by DOI 10.1038/s41586-025-08895-2 and PMC identifier 12075003.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Several hydrogen-rich superconductors have been found to show unprecedentedly high critical temperatures<sup>1-4</sup>, stimulating investigations into the nature of the superconductivity in these materials. Although their macroscopic superconducting properties are established<sup>1,5-7</sup>, microscopic insights into the pairing mechanism remains unclear. Here we characterize the superconducting gap structure in the high-temperature superconductor H<sub>3</sub>S and its deuterium counterpart D<sub>3</sub>S by performing tunnelling spectroscopy measurements. The tunnelling spectra reveal that H<sub>3</sub>S and D<sub>3</sub>S both have a fully gapped structure, which could be well described by a single s-wave Dynes model, with gap values 2Δ of approximately 60 meV and 44 meV, respectively. Furthermore, we observed gap features of another likely H-depleted H<sub>x</sub>S superconducting phase in a poorly synthesized hydrogen sulfide sample. Our work offers direct experimental evidence for superconductivity in the hydrogen-rich superconductor H<sub>3</sub>S from a microscopic perspective. It validates the phonon-mediated mechanism of superconducting pairing and provides a foundation for further understanding the origins of high-temperature superconductivity in hydrogen-rich compounds.