Version 1
: Received: 10 May 2022 / Approved: 12 May 2022 / Online: 12 May 2022 (08:57:07 CEST)
How to cite:
Marsiglio, F. Impact of Retardation in the Holstein-Hubbard Model: A Two-Site Calculation. Preprints2022, 2022050165. https://doi.org/10.20944/preprints202205.0165.v1.
Marsiglio, F. Impact of Retardation in the Holstein-Hubbard Model: A Two-Site Calculation. Preprints 2022, 2022050165. https://doi.org/10.20944/preprints202205.0165.v1.
Cite as:
Marsiglio, F. Impact of Retardation in the Holstein-Hubbard Model: A Two-Site Calculation. Preprints2022, 2022050165. https://doi.org/10.20944/preprints202205.0165.v1.
Marsiglio, F. Impact of Retardation in the Holstein-Hubbard Model: A Two-Site Calculation. Preprints 2022, 2022050165. https://doi.org/10.20944/preprints202205.0165.v1.
Abstract
Eliashberg theory provides a theoretical framework for understanding the phenomenon of superconductivity when pairing between two electrons is mediated by phonons, and retardation effects are fully accounted for. However, when a direct Coulomb interaction between two electrons is also present, this interaction is only partially accounted for. In this work we use a well-defined Hamiltonian, the Hubbard-Holstein model, to examine this competition more rigorously, using exact diagonalization on a two-site system. We find that the direct electron-electron repulsion between two electrons has a significantly more harmful effect on pairing than suggested through the standard treatment of this interaction.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
