Ab initio theory of coherent phonon generation by laser excitation

Y. Shinohara; Y. Kawashita; K. Yabana; J. -I. Iwata; T. Obote; G. F. Bertsch

Ab initio theory of coherent phonon generation by laser excitation

Materials Science 2010-06-22 v1 Computational Physics

Authors: Y. Shinohara , Y. Kawashita , K. Yabana , J. -I. Iwata , T. Obote , G. F. Bertsch

Abstract

We show that time-dependent density functional theory (TDDFT) is applicable to coherent optical phonon generation by intense laser pulses in solids. The two mechanisms invoked in phenomenological theories, namely impulsively stimulated Raman scattering and displacive excitation, are present in the TDDFT. Taking the example of crystalline Si, we find that the theory reproduces the phenomena observed experimentally: dependence on polarization, strong growth at the direct band gap, and the change of phase from below to above the band gap. We conclude that the TDDFT offers a predictive ab initio framework to treat coherent optical phonon generation.

Keywords

time-dependent density functional theory coherent phonon laser excitation silicon Raman scattering displacive excitation ab initio solid state

Cite

@article{arxiv.1006.4118,
  title  = {Ab initio theory of coherent phonon generation by laser excitation},
  author = {Y. Shinohara and Y. Kawashita and K. Yabana and J. -I. Iwata and T. Obote and G. F. Bertsch},
  journal= {arXiv preprint arXiv:1006.4118},
  year   = {2010}
}

Comments

5 pages, 5 figures

Ab initio theory of coherent phonon generation by laser excitation

Abstract

Keywords

Cite

Comments

Related papers