Eur. Phys. J. D 15, 413-422 (2001)
https://doi.org/10.1007/s100530170158

Femtosecond pump-probe fluorescence signals from classical trajectories: comparison with wave-packet calculations

¹ Fock Institute of Physics, The University of St. Petersburg, 198504 St. Petersburg, Russia
² Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

Corresponding author: ^a voen@phys-chemie.uni-wuerzburg.de

Received: 28 March 2001
Published online: 15 September 2001

Abstract

A classical approach to simulate femtosecond pump-probe experiments is presented and compared to the quantum mechanical treatment. We restrict the study to gas-phase systems using the I₂ molecule as a numerical example. Thus, no relaxation processes are included. This allows for a direct comparison between purely quantum mechanical results and those obtained from classical trajectory calculations. The classical theory is derived from the phase-space representation of quantum mechanics. Various approximate quantum mechanical treatments are compared to their classical counterparts. Thereby it is demonstrated that the representation of the radial density as prepared in the pump-process is most crucial to obtain reliable signals within the classical approach.