Fermion Condensation and Non Fermi Liquid Behavior in a Model with Long Range Forces

TL;DR

This paper analyzes Fermion condensation in a model with infinite range forces, demonstrating non-Fermi liquid behavior and examining the quasiparticle picture's validity at various temperatures.

Contribution

It provides an analytical reanalysis of Fermion condensation in a long-range interaction model, highlighting non-Fermi liquid behavior and quasiparticle validity.

Findings

Demonstrates non-Fermi liquid behavior analytically at T=0 and T≠0

Shows quasiparticle picture holds below characteristic temperature T_f

Revalidates Fermion condensation in models with infinite range interactions

Abstract

The phenomenon of the so called Fermion condensation, a phase transition analogous to Bose condensation but for Fermions, postulated in the past to occur in systems with strong momentum dependent forces, is reanalysed in a model with infinite range interactions. The strongly non Fermi Liquid behavior of this system is demonstrated analytically at $T=0$ and at $T\neq 0$ in the superconducting and normal phases. The validity of the quasiparticle picture is investigated and seems to hold true for temperatures less than the characteristic temperature $T_f$ of the Fermion condensation.