Kumar, Brijesh and Shastry, Sriram B (2003) Superconductivity in $CoO_2$ layers and the resonating valence bond meanfield theory of the triangular lattice tJ model. In: Physical Review B (Condensed Matter and Materials Physics), 68 . pp. 1045081.

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Abstract
Motivated by the recent discovery of superconductivity in twodimensional $CoO_2$ layers, we present some possibly useful results of the resonating valence bond meanfield theory applied to the triangular lattice. An interesting time reversal breaking superconducting state arises from strongly frustrated interactions. Away from half filling, the order parameter is found to be complex, and yields a fully gapped quasiparticle spectrum. The sign of the hopping plays a crucial role in the analysis, and we find that superconductivity is as fragile for one sign as it is robust for the other. $Na_xCoO_2 \cdot yH_2O$ is argued to belong to the robust case, by comparing the localdensity approximation fermi surface with an effective tightbinding model. The highfrequency Hall constant in this system is potentially interesting, since it is pointed out to increase linearly with temperature without saturation for T>Tdegeneracy.
Item Type:  Journal Article 

Additional Information:  Copyright for this article belongs to American Physical Society (APS). 
Department/Centre:  Division of Physical & Mathematical Sciences > Physics 
Date Deposited:  04 May 2006 
Last Modified:  19 Sep 2010 04:16 
URI:  http://eprints.iisc.ernet.in/id/eprint/2050 
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