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arXiv · 0901.4541

Ultrafast Magnetization Dynamics in Diluted Magnetic Semiconductors

O. Morandi·P. -A. Hervieux·G. Manfredi
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Abstract

We present a dynamical model that successfully explains the observed time evolution of the magnetization in diluted magnetic semiconductor quantum wells after weak laser excitation. Based on the pseudo-fermion formalism and a second order many-particle expansion of the exact p-d exchange interaction, our approach goes beyond the usual mean-field approximation. It includes both the sub-picosecond demagnetization dynamics and the slower relaxation processes which restore the initial ferromagnetic order in a nanosecond time scale. In agreement with experimental results, our numerical simulations show that, depending on the value of the initial lattice temperature, a subsequent enhancement of the total magnetization may be observed within a time scale of few hundreds of picoseconds.

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O. Morandi, P. -A. Hervieux, G. Manfredi. 2009-01-28. Ultrafast Magnetization Dynamics in Diluted Magnetic Semiconductors. https://doi.org/10.1088/1367-2630%2F11%2F7%2F073010

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