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Nesting, spin-fluctuations, and odd-gap superconductivity in NaxCoO2 yH2O

M. D. Johannes·I. I. Mazin·D. J. Singh·D. A. Papaconstantopoulos
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Abstract

We have calculated the one-electron susceptibility of hydrated NaxCoO2 and find strong nesting nearly commensurate with a 2X2 superstructure. The nesting involves about 70% of all electrons at the Fermi level and is robust with respect to doping. This nesting creates a tendency to a charge density wave compatible with the charge order often seen at x approx 0.5, which is usually ascribed to electrostatic repulsion of Na ions. In the spin channel, it gives rise to strong spin-fluctuations, which should be important for superconductivity. The superconducting state most compatible with this nesting structure is an odd-gap triplet s-wave state.

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M. D. Johannes, I. I. Mazin, D. J. Singh, D. A. Papaconstantopoulos. 2004-03-03. Nesting, spin-fluctuations, and odd-gap superconductivity in NaxCoO2 yH2O. https://doi.org/10.1103/physrevlett.93.097005

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