Ultrafast electron thermalization in a magnetic layered Au/Co/Au film

Arnaud Labourt-Ibarre (1) , Christophe Voisin (1) , Guillaume Cassabois (1) , Claude Delalande (1) , Christos Flytzanis (1) , Philippe Roussignol (1) , Pierre Beauvillain (2)

1 LPA - Laboratoire Pierre Aigrain
2 IEF - Institut d'électronique fondamentale

The ultrafast electron dynamics subsequent to a hundred femtosecond photo-excitation is monitored in a few nanometer thick Au/Co/Au film by means of time-resolved transient spectroscopy. We show that the insertion of the thin Co layer in the Au film leads to a drastic modification of the scattering rates of the different thermalization regimes. The electron-electron interactions are dominated by the mobile sp-electrons scattering on the heavy d-electrons, which concomitantly enhances the electron-phonon interactions by up to a factor of 5. In the framework of ultrafast magnetization dynamics, this study provides important data on the electronic processes underlying the spin dynamics in a sample typically designed for magneto-optical applications.

Domaines: Autre [cond-mat.other]

Arnaud Labourt-Ibarre, Christophe Voisin, Guillaume Cassabois, Claude Delalande, Christos Flytzanis, et al.. Ultrafast electron thermalization in a magnetic layered Au/Co/Au film. Journal of Applied Physics, 2008, 104, pp.094301. ⟨hal-00345478⟩