Strongly correlated Fermi-systems: non-Fermi liquid behavior, quasiparticle effective mass and their interplay

TL;DR

This paper uses density functional theory of fermion condensation to analyze non-Fermi liquid behavior in strongly correlated Fermi-systems, linking quasiparticle effective mass to observable thermodynamic and transport properties.

Contribution

It introduces a theoretical framework connecting quasiparticle effective mass variations to non-Fermi liquid behavior in heavy-fermion metals.

Findings

Theoretical predictions match experimental data on YbRh2Si2.

Effective mass dependence explains non-Fermi liquid thermodynamics.

Results support fermion condensation as key to understanding strongly correlated systems.

Abstract

Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh2Si2.