Behavior of Fermi Systems Approaching Fermion Condensation Quantum Phase Transition from Disordered Phase

Abstract

The behavior of Fermi systems which approach the fermion condensation quantum phase transition (FCQPT) from the disordered phase is considered. We show that the quasiparticle effective mass $M^*$ diverges as $M^*\propto 1/|x-x_{FC}|$ where $x$ is the system density and $x_{FC}$ is the critical point at which FCQPT occurs. Such a behavior is of general form and takes place in both three dimensional (3D) systems and two dimensional (2D) ones. Since the effective mass $M^*$ is finite, the system exhibits the Landau Fermi liquid behavior. At $|x-x_{FC}|/x_{FC}\ll 1$, the behavior can be viewed as a highly correlated one, because the effective mass is large and strongly depends on the density. In case of electronic systems the Wiedemann-Franz law is held and Kadowaki-Woods ratio is preserved. Beyond the region $|x-x_{FC}|/x_{FC}\ll 1$, the effective mass is approximately constant and the system becomes conventional Landau Fermi liquid.