title: The influence of the excitation pulse length on ultrafast magnetization dynamics in nickel.
abstract: The laser-induced demagnetization of a ferromagnet is caused by the temperature of the electron gas as well as the lattice temperature. For long excitation pulses, the two reservoirs are in thermal equilibrium. In contrast to a picosecond laser pulse, a femtosecond pulse causes a non-equilibrium between the electron gas and the lattice. By pump pulse length dependent optical measurements, we find that the magnetodynamics in Ni caused by a picosecond laser pulse can be reconstructed from the response to a femtosecond pulse. The mechanism responsible for demagnetization on the picosecond time scale is therefore contained in the femtosecond demagnetization experiment.
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Fognini
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Salvatella
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Gort
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Michlmayr
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Vaterlaus
authors.affiliation: Laboratory for Solid State Physics , Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Y
authors.initials: Y
authors.lastname: Acremann