IFIR   05409
INSTITUTO DE FISICA DE ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Electron-phonon interaction dressed by electronic correlations near charge ordering. Possible implications for cobaltates.
Autor/es:
A. FOUSSATS; A. GRECO; M. BEJAS; A. MURAMATSU
Revista:
JOURNAL OF PHYSICS CONDENSED MATTER
Referencias:
Año: 2006 vol. 18 p. 11411 - 11428
ISSN:
0953-8984
Resumen:
We consider possible routes to superconductivity on the basis of the tJ V model plus phonons on the triangular lattice. We studied the stabilityconditions for the homogeneous Fermi liquid (HFL) phase against different broken symmetry phases. Besides the \sqrt{3} × \sqrt{3} CDW phase, triggered by the nearest-neighbour Coulomb interaction V , we have found that the HFL is unstable, at very low doping, against a bond-ordered phase due to J . We also discuss the occurrence of phase separation at low doping and V . The interplay between the electronphonon interaction and correlations near the \sqrt{3} × \sqrt{3} CDW leads to superconductivity in the unconventional next-nearest-neighbour f-wave (NNN-f) channel with a dome shape for Tc around x ∼ 0.35, and with values of a few kelvin. Near the bond-ordered phase at low doping we found tendencies to superconductivity with d-wave symmetry for finite J and x < 0.15. Possible implications for cobaltates are discussed.