title: Catching Conical Intersections in the Act: Monitoring Transient Electronic Coherences by Attosecond Stimulated X-Ray Raman Signals.
abstract: Conical intersections (CIs) dominate the pathways and outcomes of virtually all photophysical and photochemical molecular processes. Despite extensive experimental and theoretical effort, CIs have not been directly observed yet and the experimental evidence is being inferred from fast reaction rates and some vibrational signatures. We show that short x-ray (rather than optical) pulses can directly detect the passage through a CI with the adequate temporal and spectral sensitivity. The technique is based on a coherent Raman process that employs a composite femtosecond or attosecond x-ray pulse to detect the electronic coherences (rather than populations) that are generated as the system passes through the CI.
authors.affiliation: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Kowalewski
authors.affiliation: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: Kochise
authors.initials: K
authors.lastname: Bennett
authors.affiliation: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: Konstantin E
authors.initials: KE
authors.lastname: Dorfman
authors.affiliation: Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
authors.forename: Shaul
authors.initials: S
authors.lastname: Mukamel
mesh_terms: D003198:Computer Simulation; D008962:Models, Theoretical; D055668:Photochemical Processes; D010777:Photochemistry / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*