We develop an electronic-temperature dependent interatomic potential Φ(Te) for unexcited and laser-excited silicon. The potential is designed to reproduce ab initio molecular dynamics simulations by requiring force- and energy matching for each time step. Φ(Te) has a simple and flexible analytical form, can describe all relevant interactions and is applicable for any kind of boundary conditions (bulk, thin films, clusters). Its overall shape is automatically adjusted by a self-learning procedure, which finally finds the global minimum in the parameter space. We show that Φ(Te) can reproduce all thermal and nonthermal features provided by ab initio simulations. We apply the potential to simulate laser-excited Si nanoparticles and find critical damping of their breathing modes due to nonthermal melting.
@article{arxiv.1812.08595,
title = {Self-learning analytical interatomic potential describing laser-excited silicon},
author = {Bernd Bauerhenne and Vladimir P. Lipp and Tobias Zier and Eeuwe S. Zijlstra and Martin E. Garcia},
journal= {arXiv preprint arXiv:1812.08595},
year = {2020}
}