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Possible singlet to triplet pairing transition in NaxCoO2 H2O

M. M. Maska·M. Mierzejewski·B. Andrzejewski·M. L. Foo·R. J. Cava·T. Klimczuk
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Abstract

We present precise measurements of the upper critical field (Hc2) in the recently discovered cobalt oxide superconductor. We have found that the critical field has an unusual temperature dependence; namely, there is an abrupt change of the slope of Hc2(T) in a weak field regime. In order to explain this result we have derived and solved Gor'kov equations on a triangular lattice. Our experimental results may be interpreted in terms of the field-induced transition from singlet to triplet superconductivity.

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M. M. Maska, M. Mierzejewski, B. Andrzejewski, M. L. Foo, R. J. Cava, T. Klimczuk. 2004-10-23. Possible singlet to triplet pairing transition in NaxCoO2 H2O. https://doi.org/10.1103/physrevb.70.144516

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