Coherent phonons in polycrystalline bismuth film monitored by ultrafast electron diffraction

摘要

The generation of coherent phonons in polycrystalline bismuth film is observed by ultrafast time-resolved electron diffraction. The dynamics of the diffracted intensities from the (110), (202), and (024) lattice planes show pronounced oscillations at 130–150 GHz. The anisotropy in the energy transfer rate of coherent optical phonons is discussed.