Anomalous Behavior of the Spin Susceptibility of Strongly Correlated Fermi Systems

Abstract

The spin susceptibility $\chi(T)$ of strongly correlated Fermi systems is investigated in the density region where Fermi-liquid theory fails. We attribute this failure to a specific quantum phase transition associated with a rearrangement of the Landau state at low temperatures $T$, retaining the assumption that the Landau quasiparticle picture survives in a generic sense. Taking into account the resulting modification of the quasiparticle istribution function, the spin susceptibility $\chi(T)$ is shown to contain a Curie-Weiss component $\chi_{\rm CW}(T)\sim (T-\Theta_{\rm W})^{-1}$, with the Weiss temperature $\Theta_{\rm W}$ vanishing at the critical density for the transition.