Unconventional Superconductivity and Electron Correlations in the Cobalt Oxyhydrate [Formula presented] from Nuclear Quadrupole Resonance

Tatsuya Fujimoto, Guo-Qing Zheng, Y. Kitaoka, R. L. Meng, J. Cmaidalka, C. W. Chu

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We report a careful [Formula presented] nuclear quadrupolar resonance measurement on the recently discovered cobalt oxyhydrate [Formula presented] superconductor from [Formula presented] down to 0.2 K. We find that in the normal state the spin-lattice relaxation rate [Formula presented] follows a Curie-Weiss type temperature ([Formula presented]) variation, [Formula presented], with [Formula presented], suggesting two-dimensional antiferromagnetic spin correlations. Below [Formula presented], [Formula presented] decreases with no coherence peak and follows a [Formula presented] dependence with [Formula presented] down to [Formula presented] but crosses over to a [Formula presented] variation below [Formula presented], which suggests non-[Formula presented]-wave superconductivity. The data in the superconducting state are most consistent with the existence of line nodes in the gap function.

Original languageEnglish
Number of pages1
JournalPhysical Review Letters
Issue number4
Publication statusPublished - Jan 1 2004
Externally publishedYes


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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