Disproportionation and Critical Interaction Strength in Na$_x$CoO$_2$: Concentration Dependence
Strongly Correlated Electrons
2007-05-23 v1 Superconductivity
Abstract
We present results of studies of charge disproportionation (CD) and spin differentiation in NaCoO using the correlated band theory approach (local-density approximation+Hubbard U:LDA+U). The simultaneous CD and gap opening can be followed through a first order charge disproportionation transition. By comparison with experiments, we propose a value of the Coulomb repulsion strength U() that has significant dependence on the carrier concentration , for which we obtain a phase diagram. The connection between the oxygen height and effects of on-site correlation is also reported.
Keywords
Cite
@article{arxiv.cond-mat/0508649,
title = {Disproportionation and Critical Interaction Strength in Na$_x$CoO$_2$: Concentration Dependence},
author = {K. -W. Lee and W. E. Pickett},
journal= {arXiv preprint arXiv:cond-mat/0508649},
year = {2007}
}
Comments
3 pages with 4 embedded figures. submitted to proceedings in 2005 50th MMM conference