Analysis of linear and nonlinear conductivity of plasma-like systems on the basis of the Fokker-Planck equation

TL;DR

This paper investigates the linear and nonlinear electrical conductivities of plasma-like systems using the Fokker-Planck equation, revealing how velocity-dependent friction can significantly enhance charge transport beyond traditional models.

Contribution

It introduces a generalized Fokker-Planck framework with velocity-dependent friction to analyze conductivity, providing new insights into charge transfer and non-Ohmic conductance in plasma-like systems.

Findings

Velocity-dependent friction increases electron average velocity and conductivity.

Nonlinear charge transport observed in dusty plasma, polymers, and semiconductors.

Enhanced conductivity compared to Drude model due to velocity-dependent effects.

Abstract

The problems of high linear conductivity in an electric field, as well as nonlinear conductivity, are considered for plasma-like systems. First, we recall several observations of nonlinear fast charge transport in dusty plasma, molecular chains, lattices, conducting polymers and semiconductor layers. Exploring the role of noise we introduce the generalized Fokker-Planck equation. Second, one-dimensional models are considered on the basis of the Fokker-Planck equation with active and passive velocity-dependent friction including an external electrical field. On this basis it is possible to find the linear and nonlinear conductivities for electrons and other charged particles in a homogeneous external field. It is shown that the velocity dependence of the friction coefficient can lead to an essential increase of the electron average velocity and the corresponding conductivity in comparison with the usual model of constant friction, which is described by the Drude-type conductivity. Applications including novel forms of controlled charge transfer and non-Ohmic conductance are discussed.