2026/03/31 by Mitsuaki Kawamura, Takuya Nomoto, Niklas Witt +1
Physics and Astronomy · #cond-mat.supr-con
23 pages, 5 figures
arxiv created 2026/08/06 · arxiv updated 2026/08/07
We develop a first-principles framework for evaluating the fundamental length scales of superconductivity, namely the coherence length ξ0 and the magnetic penetration depth λL, within superconducting density functional theory (SCDFT). By incorporating finite-momentum Cooper pairs, we formulate a microscopic scheme that enables a consistent and parameter-free determination of ξ0, λL, and the superconducting transition temperature Tc on the same theoretical footing. Applying the method to representative elemental superconductors, the A15 compound V3Si, and H3S under high pressure, we obtain results in good agreement with available experimental and reproduce the type-I/type-II classification across all materials studied. The unified access to ξ0 and λL further allows us to construct the Uemura plot entirely from first principles, showing that higher-Tc systems are characterized by the simultaneous realization of strong pairing and large phase stiffness. Our results establish a predictive first-principles route to superconducting length scales and provide a microscopic interpretation of empirical correlations in superconductivity.