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

作者：Lee Fan^*; Yuge Tatsuro; Shimizu Akira

来源：Journal of the Physical Society of Japan, 2012, 81(6): 064710.

DOI：10.1143/JPSJ.81.064710

• nonequilibrium steady state
• nonequilibrium molecular dynamics simulation
• electrical conduction
• doped semiconductor
• lattice vibrations
• scattering cross section
• dispersion relation
• fluctuation-dissipation relation
• temperature dependence

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.

• 出版日期2012-6