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arXiv · 1312.5404

Microscopic Properties of the Heavy-Fermion Superconductor PuCoIn$_5$ Explored by Nuclear Quadrupole Resonance

G. Koutroulakis·H. Yasuoka·H. Chudo·P. H. Tobash·J. N. Mitchell·E. D. Bauer·J. D. Thompson
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Abstract

We report $^{115}$In nuclear quadrupolar resonance (NQR) measurements on the heavy-fermion superconductor PuCoIn$_5$, in the temperature range $0.29{\rm K}\leq T\leq 75{\rm K}$. The NQR parameters for the two crystallographically inequivalent In sites are determined, and their temperature dependence is investigated. A linear shift of the quadrupolar frequency with lowering temperature below the critical value $T_c$ is revealed, in agreement with the prediction for composite pairing. The nuclear spin-lattice relaxation rate $T_1^{-1}(T)$ clearly signals a superconducting (SC) phase transition at $T_c\simeq 2.3$K, with strong spin fluctuations, mostly in-plane, dominating the relaxation process in the normal state near to $T_c$. Analysis of the $T_1^{-1}$ data in the SC state suggests that PuCoIn$_5$ is a strong-coupling $d$-wave superconductor.

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G. Koutroulakis, H. Yasuoka, H. Chudo, P. H. Tobash, J. N. Mitchell, E. D. Bauer, J. D. Thompson. 2013-12-19. Microscopic Properties of the Heavy-Fermion Superconductor PuCoIn$_5$ Explored by Nuclear Quadrupole Resonance. https://doi.org/10.1088/1367-2630/16/5/053019

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