Complex pathways influence time delay in ionization of molecules

Caption see below. Grafic: AG Sansone - Study shows how the mechanism of photoionization can be used to gain insights into complex molecular potentials How can researchers use the mechanism of photoionization to gain insight into complex molecular potential? This question has now been answered by a team led by Giuseppe Sansone from the Institute of Physics at the University of Freiburg. The researchers from Freiburg, the Max Planck Institute for Nuclear Physics in Heidelberg and groups at the Universidad Autonoma in Madrid/Spain and the University of Trieste/Italy have published their results Communications. In the origin of photoionization, also called the photoelectric effect, an atom or molecule absorbs one quantum of light, usually indicated as photon, from an external field. The energy absorbed in this process is transferred to an electron, which is freed, leaving behind a singly charged ion. In several aspects and for several applications, the effect can be regarded as instantaneous, meaning that there is no significant time delay between the absorption of the photon and the instant when the electron is emitted. However, several experiments conducted in the last years have evidenced that tiny, but measurable delays lying in the attosecond range (1 as=10-18 s) occur between these two processes.