Strong correlations and formation of "hot spots" in the quasi-one-dimensional Hubbard model at weak coupling

TL;DR

This study investigates how specific inter-chain hoppings in a quasi-one-dimensional Hubbard model lead to the formation of 'hot spots' with strong scattering, revealing the importance of frustration in momentum-dependent correlations.

Contribution

It demonstrates that second-nearest neighbor inter-chain hopping induces hot spots in the Fermi surface, highlighting the role of frustration in momentum-dependent correlation development.

Findings

Finite nearest-neighbor interchain hopping does not significantly affect momentum dependence.

Large second-nearest neighbor interchain hopping causes hot spots on the Fermi surface.

Strong correlations develop near a critical temperature, especially with frustration.

Abstract

We study the anisotropic two-dimensional Hubbard model at and near half filling within a functional renormalization group method, focusing on the structure of momentum-dependent correlations which grow strongly upon approaching a critical temperature from above. We find that a finite nearest-neighbor interchain hopping is not sufficient to introduce a substantial momentum dependence of single-particle properties along the Fermi surface. However, when a sufficiently large second-nearest neighbor inter-chain hopping is introduced, the system is frustrated and we observe the appearance of so-called "hot spots", specific points on the Fermi surface around which scattering becomes particularly strong. We compare our results with other studies on quasi-one-dimensional systems.