发表机构
TU Wien; Flatiron Institute; International School for Advanced Studies (SISSA)（维也纳工业大学; 平顿研究所; 高级研究国际学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
将动力学顶点近似扩展到延迟相互作用，提出动力学-U DΓA方法，应用于Hubbard-Holstein模型，研究电子-声子耦合对反铁磁和d波超导不稳定性的影响。
AI 中文摘要
我们将动力学顶点近似（DΓA）在其最常用的阶梯版本中扩展到具有延迟电子相互作用的系统。这种扩展方案，我们称之为“动力学-U DΓA”，使我们能够研究强相互作用电子与玻色子耦合的系统，包括在动力学平均场理论所捕获的纯局域关联之上，涵盖所有长度尺度的非局域空间关联。我们通过在方形和立方晶格上研究Hubbard-Holstein模型，聚焦于强电子关联与声子介导相互作用竞争的显著Hubbard相互作用区域，证明了该方法在耦合到单一无色散声子模式这一特定情况下的适用性。作为说明性示例，我们考虑了三维模型中的反铁磁相和二维中的d波超导体，分析了电子-声子耦合（包括其频率依赖性）对这两种不稳定性的影响。
英文摘要
We extend the dynamical vertex approximation (D$Γ$A), in its most commonly used ladder-version, to systems with retarded electronic interactions. Such an extended scheme, which we name "dynamical-$U$ D$Γ$A", allows us to study strongly interacting electrons coupled to bosons including non-local spatial correlations on all length scales on top of the purely local ones captured by dynamical mean-field theory. We demonstrate the applicability of the method in the specific case of the coupling to a single dispersionless phononic mode, by studying the Hubbard-Holstein model on the square and cubic lattices, focusing on regimes of sizable Hubbard interactions where strong electronic correlations compete with phonon-mediated interactions. As illustrative examples, we consider the antiferromagnetic phase in the three-dimensional model and the d-wave superconductor in two dimensions, analyzing the effect of the electron-phonon coupling, including its frequency dependence, on both instabilities.
