J ul 1 99 9 The interplay between flattening and damping of single particle spectra in strongly correlated Fermi systems

The self-consistent theory of the fermion condensation, a specific phase transition which results in a rearrangement of the single particle degrees of freedom in strongly correlated Fermi systems is developed. Beyond the phase transition point, the single particle spectra are shown to be flat. The interplay between the flattening and the damping of the single particle spectra at T → 0 is investigated. The width γ(ε) of the single particle states is found to grow up linearly with ε over a wide range of energy as in a marginal Fermi liquid. Our results gain insight into the success of the phenomenological theory of the normal states of high-temperature superconductors by Varma et al.