title: Noisy optical pulses enhance the temporal resolution of pump-probe spectroscopy.
abstract: Time-resolved measurements of quantum dynamics are based on the availability of controlled events that are shorter than the typical evolution time scale of the processes to be observed. Here we introduce the concept of noise-enhanced pump-probe spectroscopy, allowing the measurement of dynamics significantly shorter than the average pulse duration by exploiting randomly varying, partially coherent light fields consisting of bunched colored noise. These fields are shown to be superior by more than a factor of 10 to frequency-stabilized fields, with important implications for time-resolved experiments at x-ray free-electron lasers and, in general, for measurements at the frontiers of temporal resolution (e.g., attosecond spectroscopy). As an example application, the concept is used to explain the recent experimental observation of vibrational wave-packet motion in D(2)(+) on time scales shorter than the average pulse duration.
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Meyer
authors.forename: Christian
authors.initials: C
authors.lastname: Ott
authors.forename: Philipp
authors.initials: P
authors.lastname: Raith
authors.forename: Andreas
authors.initials: A
authors.lastname: Kaldun
authors.forename: Yuhai
authors.initials: Y
authors.lastname: Jiang
authors.forename: Arne
authors.initials: A
authors.lastname: Senftleben
authors.forename: Moritz
authors.initials: M
authors.lastname: Kurka
authors.forename: Robert
authors.initials: R
authors.lastname: Moshammer
authors.forename: Joachim
authors.initials: J
authors.lastname: Ullrich
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfeifer