On the superconducting dome near antiferromagnetic quantum critical points

TL;DR

This paper discusses the relationship between antiferromagnetic quantum critical points and the superconducting dome in heavy fermion systems, highlighting how magnetic fluctuations influence superconductivity near quantum criticality.

Contribution

It provides a theoretical analysis of how magnetic excitations near an AFQCP contribute to the formation and limits of the superconducting dome.

Findings

Superconducting dome is closely linked to magnetic quantum critical fluctuations.

Correlation length decreases as system moves away from AFQCP.

Upper bounds on the superconducting dome are derived from fluctuation behavior.

Abstract

One of the most exciting discoveries in strongly correlated systems has been the existence of a superconducting dome on heavy fermions close to the quantum critical point where antiferromagnetic order disappears. It is hard even for the most skeptical not to admit that the excitations which bind the electrons in the Cooper pairs have a magnetic origin. As a system moves away from an antiferromagnetic quantum critical point, (AFQCP) the correlation length of the fluctuations decreases and the system goes into a local quantum critical regime. The attractive interaction mediated by the non-local part of these excitations vanishes and this allows to obtain an upper bound to the superconducting dome around an AFQCP.