First-Principles Calculation of the Superconducting TransitionTemperature with determining the Coulomb Pseudopotential

考虑到格林函数方法和超导体密度泛函理论(SCDFT)之间的对应关系，我们构造了SCDFT中带隙方程中的配对势的一种新的泛函形式，使我们能够从第一原理出发，通过确定库仑赝势来计算超导转变温度T_1。我们将该框架应用于石墨层间化合物(GICs)，阐明了GICs中超导电性的微观机制。我们还从理论上探索了一条合成具有较高T_2的GICs以及获得高温超导体的途径，我们认为，要获得高温超导体，需要有几乎抵消了强电子-电子斥力的强声子相互作用。

By considering the correspondence between the Green’s-function approach and the density-functional theory for superconductors (SCDFT), we have constructed a new functional form for the pairing potential appearing in the gap equation in the SCDFT, which enables us to calculate the superconducting transition temperature T_ from first principles with the determination of the Coulomb pseudopotential. We have applied this framework to the graphite intercalation compounds (GICs) and clarified the microscopic mechanism of superconductivity in GICs. We have also made a theoretical search for a path to synthesize GICs with higher T_, as well as to obtain high-temperature superconductors for which we conclude that strong phonon-mediated interactions with almost cancelling strong electron-electron repulsions are needed.