SUPERCONDUCTIVITY IN AN EXTENDED HUBBARD-MODEL DUE TO SPIN AND CHARGEFLUCTUATIONS

Authors
Citation
L. Tewordt et T. Dahm, SUPERCONDUCTIVITY IN AN EXTENDED HUBBARD-MODEL DUE TO SPIN AND CHARGEFLUCTUATIONS, Physica. C, Superconductivity, 235, 1994, pp. 2163-2164
Citations number
5
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Applied
ISSN journal
0921-4534
Volume
235
Year of publication
1994
Part
4
Pages
2163 - 2164
Database
ISI
SICI code
0921-4534(1994)235:<2163:SIAEHD>2.0.ZU;2-Y
Abstract
The eigenvalues of the superconducting states of the three-band Hubbar d model are calculated as functions of band-filling n, on-site repulsi on U, and Cu-O repulsion V. We take full into account the momentum and energy dependence of the pairing interaction due to exchange of spin and charge fluctuations. Near the spin-density-wave instability the le ading eigenvalue is that of the pairing state with d(x)2(-y)2 symmetry . This eigenvalue, lambda(d), increases rapidly and passes through uni ty as V is increased towards the charge-density-wave instability. The superconducting order parameter phi(d)(($) over right arrow k,omega) s hows a ($) over right arrow k-dependence which deviates substantially from the simplest form cos (pi k(x)) - cos (pi k(y)), and Im phi(d)(($ ) over right arrow k,omega) exhibits a large and narrow peak as functi on of omega at the characteristic energy of the spin fluctuation mode.