First-principles calculation to explore mechanisms of coherent phonon generation

Shinohara, Yasushi*; Otobe, Tomohito; Iwata, Junichi*; Yabana, Kazuhiro*

Coherent phonon is the macroscopic coherent oscillation of atoms in a solid state generating under the ultrafast laser pulse which is shorter than the frequency of the phonon. Some physical processes for the coherent phonon have been proposed. We are studying the computational method describing the dynamics of the electron and atom employing the time-dependent density functional theory. Our computational results show the origine of the coherent phonon in Si quantitatively.