title: Ultrafast time-resolved faraday rotation in EuO thin films.
abstract: We have investigated the ultrafast spin dynamics in EuO thin films by time-resolved Faraday rotation spectroscopy. The photoinduced magnetization is found to be increased in a transient manner, accompanied with subsequent demagnetization. The dynamical magnetization enhancement showed a maximum slightly below the Curie temperature with prolonged tails toward both lower and higher temperatures and dominates the demagnetization counterpart at 55 K. The magnetization enhancement component decays in ~1 ns. The realization of the transient collective ordering is attributable to the enhancement of the f-d exchange interaction.
authors.affiliation: Quantum Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Liu
authors.forename: T
authors.initials: T
authors.lastname: Makino
authors.forename: T
authors.initials: T
authors.lastname: Yamasaki
authors.forename: K
authors.initials: K
authors.lastname: Ueno
authors.forename: A
authors.initials: A
authors.lastname: Tsukazaki
authors.forename: T
authors.initials: T
authors.lastname: Fukumura
authors.forename: Y
authors.initials: Y
authors.lastname: Kong
authors.forename: M
authors.initials: M
authors.lastname: Kawasaki