Quantifying the role of antiferromagnetic fluctuations in the superconductivity of the doped Hubbard model

TL;DR

This paper investigates how antiferromagnetic spin fluctuations contribute to superconductivity in the doped Hubbard model, revealing that only about half of the pairing mechanism can be explained by spin fluctuations alone.

Contribution

It provides a quantitative analysis of the electron-spin fluctuation coupling's role in superconductivity, challenging the notion that spin fluctuations are the sole pairing mechanism.

Findings

Only about 50% of superconductivity is due to spin fluctuation pairing.

Standard one-loop theory overestimates the role of spin fluctuations.

DCA with Monte Carlo offers precise insights into pairing mechanisms.

Abstract

We study the contribution of the electron-spin fluctuation coupling to the superconducting state of the two dimensional Hubbard model within dynamical cluster approximation (DCA) using a numerical exact continuous time Monte Carlo solver. By analyzing the frequency dependence of the self energy, we show that only about half of the superconductivity can be attributed to a "pairing glue" arising from treating spin fluctuations as a pairing boson in the standard one-loop theory.