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Screening, Coulomb pseudopotential, and superconductivity in alkali-doped Fullerenes

Erik Koch·Olle Gunnarsson·Richard M. Martin
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Abstract

We study the static screening in a Hubbard-like model using quantum Monte Carlo. We find that the random phase approximation is surprisingly accurate almost up to the Mott transition. We argue that in alkali-doped Fullerenes the Coulomb pseudopotential $μ^\ast$ is not very much reduced by retardation effects. Therefore efficient screening is important in reducing $μ^{\ast}$ sufficiently to allow for an electron-phonon driven superconductivity. In this way the Fullerides differ from the conventional picture, where retardation effects play a major role in reducing the electron-electron repulsion.

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Erik Koch, Olle Gunnarsson, Richard M. Martin. 1999-02-17. Screening, Coulomb pseudopotential, and superconductivity in alkali-doped Fullerenes. https://doi.org/10.1103/physrevlett.83.620

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