Comparison of the phase diagram of the half-filled layered organic superconductors with the phase diagram of the RVB theory of the Hubbard-Heisenberg model

Preprint
Publisher Website
Google Scholar
  • 5 October 2004
Abstract
We present a resonating valence bond (RVB) theory of superconductivity for the Hubbard-Heisenberg model on an anisotropic triangular lattice. We show that these calculations are consistent with the observed phase diagram of the half-filled layered organic superconductors, such as the beta, beta', kappa and lambda phases of (BEDT-TTF)_2X and (BETS)_2X. We find a first order transition from a Mott insulator to a d_{x^2-y^2} superconductor with a small superfluid stiffness and a pseudogap with d_{x^2-y^2} symmetry. The Mott-Hubbard transition can be driven either by increasing the on-site Coulomb repulsion, U, or by increasing the ratio of the two hopping integrals, t'/t. Our results suggest that the ratio t'/t plays an important role in determining the phase diagram of the organic superconductors.

This publication has 0 references indexed in Scilit: