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The nuclear spin-lattice relaxation rate in the PuMGa$_5$ materials

Yunkyu Bang·M. J. Graf·N. J. Curro·A. V. Balatsky
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Abstract

We examine the nuclear spin-lattice relaxation rates $1/T_1$ of PuRhGa$_5$ and PuCoGa$_5$, both in the superconducting and normal states, as well as their Knight shifts. Results for both compounds are consistent with a superconducting gap of d-wave symmetry in the presence of strong impurity scattering, though with quite different gap-over-$T_c$ ratios $2 Δ_{0}/ k_B T_c$ (8 for PuCoGa$_5$ and 5 for PuRhGa$_5$). In the normal state, PuRhGa$_5$ exhibits a gradual suppression of $(T_1 T)^{-1}$ below 25 K, while measurements for PuCoGa$_5$ reveal a monotonic increase down to $T_c$. We propose that this behavior is consistently understood by the crossover from the two-dimensional quantum antiferromagnetic regime of the local $5f$-electron spins of Pu to the concomitant formation of the fermion pseudogap based on the two-component spin-fermion model.

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Yunkyu Bang, M. J. Graf, N. J. Curro, A. V. Balatsky. 2006-03-30. The nuclear spin-lattice relaxation rate in the PuMGa$_5$ materials. https://doi.org/10.1103/physrevb.74.054514

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