Energy conservation and pressure relaxation in an extended two-temperature model for copper with an electron temperature-dependent interaction potential

Abstract

An implementation of an electron temperature-dependent interaction potential for copper in a two-temperature model-molecular dynamics framework is presented. An algorithm for enforcing energy conservation when using such an interaction is provided that is needed due to the changing interaction strength with the degree of excitation. Furthermore, focus is put on how to treat the pressure differences due to an electron temperature gradient following laser irradiation. The influence of various extensions is investigated in large-scale two-temperature model molecular dynamics simulations and compared to existing approaches.