Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.20: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Spin-dependent hot electron lifetimes of 3d ferromagnets — •Marko Wietstruk1, Kristian Döbrich2, Cornelius Gahl1, Andreas Goris1,2, and Martin Weinelt1 — 1Freie Universität Berlin, FB Physik — 2Max-Born-Institut, Berlin
Hot electrons excited few 100 meV above the Fermi energy (EF) play a major role in, e.g., spin injection and optically induced magnetization dynamics. Also spin-dependent transport relies on the difference in hot electron lifetimes of majority and minority electrons. While theory proposes large lifetime asymmetries near EF, only very few experimental evidence is given.
In time- and spin-resolved two-photon photoemission experiments (2PPE) we investigated laser induced hot electrons of the 3d ferromagnets Fe, Co and Ni. Their lifetimes were determined by simulations using optical Bloch equations.
In contrast to the theory we found a significantly smaller difference between majority and minority lifetimes that decreases even further when approaching EF. This discrepancy can be explained by considering secondary electrons as well as exchange scattering [1].
[1] A. Goris et al., Phys. Rev. Lett. 107, 026601 (2011)