Valence shell one-photon photoelectron circular dichroism in chiral systems

Abstract

Photoelectron circular dichroism, or PECD, an intense forward–backward asymmetry with respect to the light's propagation axis observed in the photoelectron angular distribution when a chiral target is ionized by circularly polarized light, was first predicted nearly four decades ago but progress could not start until the appropriate theoretical and experimental tools were developed. This article reviews the advancements made on this subject since the first theoretical and experimental studies in the early 2000's up to the current date, with a particular emphasis on single-photon valence-shell ionization induced by VUV continuous sources such as synchrotron radiation and observed by electron imaging. After a review of the available theoretical and experimental tools and their performances, the main properties of this chiroptical probe will be put forward through relevant examples, and especially its sensitivity to subtle details of the molecular potential with respect to more commonly known electron scattering parameters such as cross-sections or angular anisotropy parameters. As such, its ability to probe static molecular structures such as conformers, isomers, clustering, chemical substitution, as well as dynamical ones such as vibrations will be discussed, together with future perspectives related to its fundamental and analytical properties to be studied in the time domain with fs laser sources including High Harmonic Generation and Free Electron Lasers.