Photoinduced coherent phonons in bismuth

The equation of the photoinduced dynamics for atoms of the crystal lattice of Bi has been obtained. The time dependence of atomic shifts under the effect of an ultrashort laser pulse on the crystal has been calculated based on this equation. It has been shown that the frequency of the oscillating part of the shifts depends on the energy density of the laser pulse and time. The intensity of the Fourier spectrum of photoinduced coherent vibrations of the crystal lattice (coherent phonons) has been calculated. The obtained theoretical results have been compared with the experimental data.