Relaxation of an Electron System : Conserving Approximation
Abstract
The dynamic response of an interacting electron system is determined by an extension of the relaxation-time approximation forced to obey local conservation laws for number, momentum and energy. A consequence of these imposed constraints is that the local electron equilibrium distribution must have a space- and time-dependent chemical potential, drift velocity and temperature. Both quantum kinetic and semi-classical arguments are given, and we calculate and analyze the corresponding analytical d-dimensional dielectric function. Dynamical correlation, arising from relaxation effects, is shown to soften the plasmon dispersion of both two- and three-dimensional systems. Finally, we consider the consequences for a hydrodynamic theory of a d-dimensional interacting electron gas, and by incorporating the competition between relaxation and inertial effects we derive generalised hydrodynamic equations applicable to arbitrary frequencies.
Cite
@article{arxiv.cond-mat/0107348,
title = {Relaxation of an Electron System : Conserving Approximation},
author = {G. S. Atwal and N. W. Ashcroft},
journal= {arXiv preprint arXiv:cond-mat/0107348},
year = {2009}
}
Comments
Revtex4. 16 pages, 6 figures. Typos have been corrected