Classical behavior of strongly correlated Fermi systems near a quantum critical point. Transport properties

TL;DR

This paper investigates the classical transport behavior in strongly correlated Fermi systems near a quantum critical point, highlighting the emergence of a softly damped transverse zero sound mode affecting low-temperature kinetics.

Contribution

It introduces the concept of a softly damped transverse zero sound mode near a quantum critical point in strongly correlated Fermi systems, explaining classical transport at low temperatures.

Findings

Emergence of a softly damped transverse zero sound mode near quantum criticality.

Suppression of damping leads to classical transport behavior at low temperatures.

Divergence of the density of states at the critical point influences transport properties.

Abstract

The low-temperature kinetics of the strongly correlated electron liquid inhabiting a solid is analyzed. It is demonstrated that a softly damped branch of transverse zero sound emerges when several bands cross the Fermi surface simultaneously near a quantum critical point at which the density of states diverges. Suppression of the damping of this branch occurs due to a mechanism analogous to that affecting the phonon mode in solids at room temperature, giving rise to a classical regime of transport at extremely low temperatures in the strongly correlated Fermi system.