Ultrafast dynamics evidence of strong coupling superconductivity in LaH<sub>10±δ</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39516225.
- Also identified by DOI 10.1038/s41467-024-53103-w and PMC identifier 11549371.
- Licence recorded as CC BY-NC-ND.
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Abstract
Recently, tremendous research interest has been aroused in clathrate superhydrides. However, their microscopic properties, especially the superconducting (SC) gap and electron-phonon coupling (EPC) strength, are largely unexplored experimentally. Here, we investigate the time-resolved ultrafast spectroscopy of a superconductor LaH<sub>10±δ</sub> under an ultrahigh pressure of 165 GPa. By analyzing the ultrafast dynamics of the quasiparticles, we experimentally obtain the SC gap Δ(0) = 53 ± 5 meV, revealing a gap ratio 2Δ(0)/k<sub>B</sub>T<sub>c</sub> = 5.6 and a gap parameter ϑ = 1.95. Significantly, we experimentally estimate <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>λ</mi> <mo>⟨</mo> <msup><mrow><mi>Ω</mi></mrow> <mrow><mn>2</mn></mrow> </msup> <mo>⟩</mo></math> = (2.4 ± 0.1) × 10<sup>4</sup> (meV)<sup>2</sup>, which corresponds to an EPC strength λ = 2.58 ± 0.11. These results together provide direct experimental evidence that strong EPC is responsible for the near-room-temperature superconductivity in clathrate superhydrides. Our investigation significantly advances the experimental exploration of superhydrides, and contributes to the ultrafast dynamics investigations of quantum materials under high pressures.