Magnetic and superconducting correlations in the two-dimensional Hubbard model

TL;DR

This paper investigates how magnetic and superconducting correlations develop and compete in the 2D Hubbard model using functional renormalization group and mean-field methods, revealing potential symmetry breaking and effects on single-particle properties.

Contribution

It combines functional renormalization group and mean-field approaches to analyze magnetic and superconducting correlations in the 2D Hubbard model, highlighting the interplay and strong correlation effects.

Findings

Flow to strong coupling suggests possible symmetry breaking.

Simultaneous magnetic and superconducting order can be analyzed.

Strong correlations significantly affect single-particle properties.

Abstract

The interplay and competition of magnetic and superconducting correlations in the weakly interacting two-dimensional Hubbard Model is investigated by means of the functional renormalization group. At zero temperature the flow of interactions in one-loop approximation evolves into a strong coupling regime at low energy scales, signalling the possible onset of spontaneous symmetry breaking. This is further analyzed by a mean-field treatment of the strong renormalized interactions which takes into account magnetic and superconducting order simultaneously. The effect of strong correlations on single-particle properties in the normal phase is studied by calculating the flow of the self-energy.