Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI

C Gutt; T Sant; D Ksenzov; F Capotondi; E Pedersoli; L Raimondi; I P Nikolov; M Kiskinova; S Jaiswal; G Jakob; M Kläui; H Zabel; U Pietsch

doi:10.1063/1.4990650

Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI

Struct Dyn. 2017 Jul 6;4(5):055101. doi: 10.1063/1.4990650. eCollection 2017 Sep.

Authors

C Gutt¹, T Sant¹, D Ksenzov¹, F Capotondi², E Pedersoli², L Raimondi², I P Nikolov², M Kiskinova², S Jaiswal, G Jakob³, M Kläui³, H Zabel³, U Pietsch¹

Affiliations

¹ Physics Department, University of Siegen, D-57072 Siegen, Germany.
² Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy.
³ Institut für Physik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany.

Abstract

We report the results of resonant magnetic XUV reflectivity experiments performed at the XUV free-electron laser FERMI. Circularly polarized XUV light with the photon energy tuned to the Fe M_2,3 edge is used to measure resonant magnetic reflectivities and the corresponding Q-resolved asymmetry of a Permalloy/Ta/Permalloy trilayer film. The asymmetry exhibits ultrafast changes on 240 fs time scales upon pumping with ultrashort IR laser pulses. Depending on the value of the wavevector transfer Q_z , we observe both decreasing and increasing values of the asymmetry parameter, which is attributed to ultrafast changes in the vertical spin and charge density profiles of the trilayer film.