Anisotropic spin fluctuations and superconductivity in "115'' heavy fermion compounds: 59Co NMR study in PuCoGa5

TL;DR

This study uses $^{59}$Co NMR to investigate anisotropic spin fluctuations in PuCoGa5, revealing their role in mediating superconductivity in this heavy fermion compound.

Contribution

It provides the first detailed NMR analysis of spin fluctuation anisotropy in PuCoGa5, linking it to superconductivity mechanisms.

Findings

Anisotropic spin fluctuations with finite wave vector q were observed.

Antiferromagnetic XY-type anisotropy influences superconductivity.

Comparison with related compounds highlights the role of spin fluctuation anisotropy.

Abstract

We report results of $^{59}$Co nuclear magnetic resonance measurements on a single crystal of superconducting PuCoGa5 in its normal state. The nuclear spin-lattice relaxation rates and the Knight shifts as a function of temperature reveal an anisotropy of spin fluctuations with finite wave vector q. By comparison with the isostructural members, we conclude that antiferromagnetic XY-type anisotropy of spin fluctuations plays an important role in mediating superconductivity in these heavy fermion materials.