title: Ultrafast probing of collective electron dynamics driven by dielectronic repulsion.
abstract: We use the time-dependent R-matrix approach to investigate an ultrashort pump-probe scheme to observe collective electron dynamics in C+. The ionization probability of a coherent superposition of the 2s2p;{2} 2D and 2S states shows rapid modulation due to collective dynamics of the two equivalent 2p electrons, with the modulation frequency linked to the dielectronic repulsion. The best insight into this collective dynamics is achieved by a transformation from LS symmetry to the uncoupled basis. Such dynamics may be important in high-harmonic generation using open-shell atoms and ions.
authors.affiliation: Centre for Theoretical Atomic, Molecular, and Optical Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom.
authors.forename: M A
authors.initials: MA
authors.lastname: Lysaght
authors.forename: P G
authors.initials: PG
authors.lastname: Burke
authors.forename: H W
authors.initials: HW
authors.lastname: van der Hart