Nested-Fermi-liquid theory

The susceptibility and quasiparticle self-energy are found to exhibit anomalous behavior in nested-Fermi-liquid (NFL) systems that have nearly parallel sections of the Fermi surface. Electron-electron scattering yields damping much stronger than the conventional electron-gas result and predicts a linear temperature variation of the resistivity. The susceptibility ${\mathrm{\chi }}_{\mathrm{NFL}}^{\mathrm{″}}$(q,ω) for nested fermions is calculated at q≃Q, where Q is a typical nesting wave vector. The NFL susceptibility is linear in frequency up to a crossover region near ω≃4T where a saturation to a constant value occurs. The above features, as well as various theoretical constraints, are highly sensitive to the strength of the electron-electron coupling and to the degree of nesting. The relevance of the NFL results to superconducting oxides is briefly examined, with emphasis on the resistivity and the photoemission data, which supports the calculated damping Γ(ω>T)≃αω with an intermediate on-site Coulomb coupling.