Theory of the marginal-Fermi-liquid spectrum and pairing in a local copper oxide model
Clément Sire, Chandra Mohan Varma, Andrei E. Ruckenstein +1 more
We solve for the properties of an impurity model abstracted from a model of copper oxide superconductors. At mixed valence, provided that Friedel's screening condition is satisfied, the marginal-Fermi-liquid spectrum is obtained for the spin and charge susceptibilities. The frequency dependence of the self-energies is \ensuremath{\Sigma}(\ensuremath{\omega})\ensuremath{\sim}\ensuremath{\omega} ln\ensuremath{\omega}+i\ensuremath{\omega}. This critical point is surrounded by two different Fermi-liquid phases. A simplified two-impurity version of this model is also addressed, and presents similar features, including a logarithmic divergence for coherent pair susceptibility.
Physical Review Letters•Apr 11, 1994•30 citations