A Common Thread

TL;DR

This paper proposes that spin-fluctuation mediated pairing is the fundamental mechanism behind superconductivity in heavy fermion, cuprate, and Fe-based superconductors, based on experimental and theoretical evidence.

Contribution

It introduces the idea that spin fluctuations serve as the common pairing mechanism across different classes of unconventional superconductors.

Findings

Evidence from phase diagrams and neutron resonance supports spin-fluctuation pairing.

Hubbard models replicate key properties of these materials.

Momentum and frequency dependence studies point to spin fluctuations as the pairing glue.

Abstract

The structures, the phase diagrams, and the appearance of a neutron resonance in the superconducting state provide phenomenological evidence which relate the heavy fermion, cuprate and Fe superconductors. Single- and multi-band Hubbard models have been found to describe a number of the observed properties of these materials so that it is reasonable to examine the origin of the pairing interaction in these models. Here based on the experimental phenomenology and studies of the momentum and frequency dependence of the pairing interaction for Hubbard-like models, we suggest that spin-fluctuation mediated pairing is the common thread linking this broad class of superconducting materials.