title: Ultrafast electronic excitations of small sodium clusters and the onset of electron thermalization.
abstract: In this paper we report simulations of the ultrafast laser excitation and relaxation of the correlated valence electrons of a Na(8) cluster. The aim is twofold: first, while the total energy stays constant when the exciting laser pulse is over, we observe that the entropy computed from the reduced one electron density matrix rises on a much longer time scale. We discuss whether this can be understood as the onset of the thermalization of a finite system. Second, we describe this process with eight different methods of wavefunction-based electronic structure theory, which have been adapted for an explicitly time-dependent description. Their respective advantages and limitations for the simulation of the excitation and subsequent relaxation are explained.
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Klamroth
authors.forename: M
authors.initials: M
authors.lastname: Nest