Superfluidity in system with fermion condensate
Khodel' V. A. , Shaginyan V. R.
The properties of Fermi systems beyond the phase transition point, at which the group velocity of the quasiparticles changes sign on the Fermi surface, are analyzed. A Fermi condensate arises in the new phase: The energies e(p) of quasiparticles with momenta/7lc <p<p2c (Pic <Pf>Pic >Pf) turn out to be identical and equal to the chemical potential μ. If a Cooper pairing can occur in this phase, the gap Δ is a linear function of the pairing constant λ.