Münster 1999 – wissenschaftliches Programm

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AM: Magnetismus

AM 19: Mikromagnetismus, Magnetisierungsprozesse und Dom
änenstrukturen II

AM 19.9: Vortrag

Donnerstag, 25. März 1999, 16:30–16:45, F4

Ultrafast spin dynamics in ferromagnetic Ni — •Wolfgang Hübner and Guoping Zhang — Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle

Motivated by recent experiments, we present a theoretical study of the ultrafast spin dynamics in Ni, employing a many-body Hamiltonian which includes correlation, exchange interaction, and spin-orbit coupling. We do not only examine the effects of these material-specific parameters but also those of experiment-specific parameters, such as laser-pulse width and pulse shape. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling [1]. Our theory yields that the intrinsic speed limit for spin dynamics is about 10 fs. Thus, in most of the present experiments, it is still possible to observe a much faster magnetic responsethan seen so far. As an example, we discuss in particular pump-probe linear and nonlinear magneto-optics.
W. Hübner and G. P. Zhang, Phys. Rev. B 58, R5920 (1998).