title: Feedback effect during ultrafast demagnetization dynamics in ferromagnets.
abstract: Motivated by the recent controversy about the importance of spin-flip scattering for ultrafast demagnetization in ferromagnets, we study the spin-dependent electron dynamics based on a dynamical Elliott-Yafet mechanism. The key improvement to earlier approaches is the use of a modified Stoner model with a dynamic exchange splitting between majority and minority bands. In the framework of our microscopic model, we find a novel feedback effect between the time-dependent exchange splitting and the spin-flip scattering. This feedback effect allows us to reproduce important properties of the demagnetization dynamics quantitatively. Our results demonstrate that in general Elliott-Yafet spin-flip scattering needs to be taken into account to obtain a microscopic picture of demagnetization dynamics.
authors.affiliation: Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schrödinger-Straße 46, 67663 Kaiserslautern, Germany.
authors.forename: B Y
authors.initials: BY
authors.lastname: Mueller
authors.forename: A
authors.initials: A
authors.lastname: Baral
authors.forename: S
authors.initials: S
authors.lastname: Vollmar
authors.forename: M
authors.initials: M
authors.lastname: Cinchetti
authors.forename: M
authors.initials: M
authors.lastname: Aeschlimann
authors.forename: H C
authors.initials: HC
authors.lastname: Schneider
authors.forename: B
authors.initials: B
authors.lastname: Rethfeld