Damping of long-wavelength collective excitations in quasi-onedimensional Fermi liquids

TL;DR

This paper investigates the intrinsic damping of long-wavelength collective excitations in quasi-one-dimensional Fermi liquids by analyzing the exchange-correlation kernel and two-particle-hole pair processes, providing insights into their damping mechanisms.

Contribution

It introduces an approximate method to evaluate the exchange-correlation kernel accounting for two-particle-hole excitations in quasi-1D Fermi liquids, advancing understanding of damping phenomena.

Findings

Calculated damping rate of collective density fluctuations

Contrasted results with Luttinger liquid theory

Highlighted the role of two-particle-hole processes

Abstract

The imaginary part of the exchange-correlation kernel in the longitudinal current-current response function of a quasi-onedimensional Fermi liquid is evaluated by an approximate decoupling in the equation of motion for the current density, which accounts for processes of excitation of two particle-hole pairs. The two-pair spectrum determines the intrinsic damping rate of long-wavelength collective density fluctuations, which is calculated and contrasted with a result previously obtained for a clean Luttinger liquid.