论文标题
在荷斯坦 - 哈伯德模型中延迟的影响：两端计算
Impact of Retardation in the Holstein-Hubbard Model: a two-site Calculation
论文作者
论文摘要
Eliashberg理论提供了一个理论框架，用于理解两个电子之间的配对时，由声子介导了超导性现象，并且延迟效应被充分考虑了。但是，当还存在两个电子之间的直接库仑相互作用时，仅部分考虑了这种相互作用。在这项工作中，我们使用定义明确的哈密顿 - 荷尔斯坦模型，更严格地检查这项竞争，并在两个站点系统上使用精确的对角线化。我们发现，两个电子之间的直接电子电子排斥对配对的有害影响要比通过这种相互作用的标准处理所建议的要高得多。
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.
