TY - JOUR

T1 - Unconventional Superconductivity and Electron Correlations in the Cobalt Oxyhydrate [Formula presented] from Nuclear Quadrupole Resonance

AU - Fujimoto, Tatsuya

AU - Zheng, Guo qing

AU - Kitaoka, Y.

AU - Meng, R. L.

AU - Cmaidalka, J.

AU - Chu, C. W.

PY - 2004

Y1 - 2004

N2 - 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.

AB - 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.

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U2 - 10.1103/PhysRevLett.92.047004

DO - 10.1103/PhysRevLett.92.047004

M3 - Article

AN - SCOPUS:85038300978

SN - 0031-9007

VL - 92

SP - 4

JO - Physical review letters

JF - Physical review letters

IS - 4

ER -