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arXiv · 0908.0707

Femtosecond Coherent Control of Spin with Light in (Ga,Mn)As ferromagnets

M. D. Kapetanakis·I. E. Perakis·K. J. Wickey·C. Piermarocchi·J. Wang
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Abstract

Using density matrix equations of motion, we predict a femtosecond collective spin tilt triggered by nonlinear, near--ultraviolet ($\sim$3eV), coherent photoexcitation of (Ga,Mn)As ferromagnetic semiconductors with linearly polarized light. This dynamics results from carrier coherences and nonthermal populations excited in the \{111\} equivalent directions of the Brillouin zone and triggers a subsequent uniform precession. We predict nonthermal magnetization control by tuning the laser frequency and polarization direction. Our mechanism explains recent ultrafast pump--probe experiments.

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M. D. Kapetanakis, I. E. Perakis, K. J. Wickey, C. Piermarocchi, J. Wang. 2009-08-05. Femtosecond Coherent Control of Spin with Light in (Ga,Mn)As ferromagnets. https://doi.org/10.1103/physrevlett.103.047404

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