Nonequilibrium Molecular Dynamics Simulation of Interacting Many Electrons Scattered by Lattice Vibrations

TL;DR

This paper introduces a classical MD model for electrical conductors with electrons and atoms, accurately reproducing quantum scattering effects and confirming fundamental physical laws through nonequilibrium simulations.

Contribution

The paper develops a novel classical MD model that incorporates quantum-mechanically accurate electron-atom scattering cross sections for nonequilibrium simulations.

Findings

Confirmed Ohm's law in simulations

Reproduced dispersion relations and fluctuation-dissipation relation

Obtained realistic temperature dependence of conductivity

Abstract

We propose a new model suitable for a nonequilibrium molecular dynamics (MD) simulation of electrical conductors. The model consists of classical electrons and atoms. The atoms compose a lattice vibration system. The electrons are scattered by electron-electron and electron-atom interactions. Since the scattering cross section is physically more important than the functional form of a scattering potential, we propose to devise the electron-atom interaction potential in such a way that its scattering cross section agrees with that of quantum-mechanical one. To demonstrate advantages of the proposed model, we perform a nonequilibrium MD simulation assuming a doped semiconductor at room or higher temperature. In the linear response regime, we confirm Ohm's law, the dispersion relations and the fluctuation-dissipation relation. Furthermore, we obtain reasonable dependence of the electrical conductivity on temperature, despite the fact that our model is a classical model.