Abstract
Abstract Searching for ambient-pressure conventional superconductors with critical temperatures (T C) higher than 40 K is a key challenge in the field of high-temperature superconductivity, mainly due to lack of efficient and effective models for rapidly screening candidate systems. In this work, we propose a simplified model that separates the dimensionless electron-phonon coupling (EPC) strength $$\lambda$$ λ into two components: while the EPC matrix elements evaluating the pairing strength are computationally expensive to obtain, the phonon-assisted nesting function $$P\left(\omega \right)$$ P ω , which evaluates the matching of electron bands and phonon spectra for forming potential electron pairs via phonons, can be easily and accurately calculated. Our model illuminates the critical role of $$P\left(\omega \right)$$ P ω and its spectral integral $$P$$ P in determining $$\lambda$$ λ , i.e., high $$P$$ P is a necessary condition leading to large $$\lambda$$ λ and thus high T C, which is further demonstrated by showing that the reported high-T C traditional superconductors in literatures all have high $$P$$ P . As an easily quantifiable parameter, $$P\left(\omega \right)$$ P ω and $$P$$ P provide an efficient and effective descriptor for accelerating the discovery and rational design of high-T C superconductors. By applying the model to screen over the Computational 2D Materials Database (C2DB), we successfully identify several high-T C superconducting systems as confirmed by accurate first-principles calculations. Our model opens new avenues for exploring high-T C systems.