Femtosecond Diffraction with Laser-driven Hard X-ray Sources: Nuclear Motions and Transient Charge Densities

Abstract

Compact laser-driven sources of femtosecond hard X-ray pulses allow for ultrafast diffraction experiments on the laboratory scale. This chapter gives an account of X-ray source technologies and experimental diffraction methods. The strong potential of this approach for elucidating elementary structure-changing processes is illustrated with prototypical experimental results. A presentation of nonequilibrium phonon dynamics in bulk LiNbO3 and perovskite superlattices is complemented by an in-depth discussion of transient charge density maps and polarization dynamics in ferroelectrics, as observed in femtosecond powder diffraction experiments.