$1/T_1$ in the D-wave superconducting state with coexisting antiferromagnetism

TL;DR

This paper investigates how coexisting antiferromagnetism affects the D-wave superconducting gap, leading to additional nodes and altered impurity responses, with implications for heavy-fermion superconductor experiments.

Contribution

It introduces a model of a D-wave gap with coexisting AFM order that develops additional nodes without symmetry breaking, affecting impurity responses.

Findings

The AFM order induces extra nodes in the D-wave gap.

The modified gap shows different impurity response compared to standard D-wave.

Implications for interpreting $1/T_1$ measurements in heavy-fermion superconductors.

Abstract

We consider a general D-wave superconducting gap function in the presence of coexisting antiferromagnetic (AFM) long-rang order. We find that the D-wave order parameter develops additional nodes without lowering the symmetry of the state due to the interplay of the superconducting and AFM correlations. This AFM correlated D-wave gap has a small gap structure inside the generic D-wave gap. As a result of this additional structure it shows a quite different response to impurities compared to a standard D-wave gap. We calculate the nuclear spin-lattice relaxation rate $1/T_1$ of this gap in the presence of impurities and discuss the implications for the experiments of some AFM heavy- fermion superconductors and in particular for CeRhIn5.