English

$\textit{Ab initio}$ evidence for nonthermal characteristics in ultrafast laser melting

Materials Science 2016-12-06 v2

Abstract

Laser melting of semiconductors has been observed for almost 40 years; surprisingly, it is not well understood where most theoretical simulations show a laser-induced thermal process. Ab initio\textit{Ab initio} nonadiabatic simulations based on real-time time-dependent density functional theory reveal intrinsic nonthermal melting of silicon, at a temperature far below the thermal melting temperature of 1680 K. Both excitation threshold and time evolution of diffraction intensity agree well with experiment. Nonthermal melting is attributed to excitation-induced drastic changes in bonding electron density, and the subsequent decrease in the melting barrier, rather than lattice heating as previously assumed in the two-temperature models.

Keywords

Cite

@article{arxiv.1602.00387,
  title  = {$\textit{Ab initio}$ evidence for nonthermal characteristics in ultrafast laser melting},
  author = {Chao Lian and S. B. Zhang and Sheng Meng},
  journal= {arXiv preprint arXiv:1602.00387},
  year   = {2016}
}