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

概要

論文の詳細を見る
We propose a new model suitable for a nonequilibrium molecular dynamics (MD) simulation of electrical conductors in both linear- and nonlinear-response regimes. 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 illustrate 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. In the nonlinear response regime, we find that the response of the current to the electric field becomes strongly nonlinear, and the electron temperature rises nonlinearly as a function of the Joule heat.
2012-06-15