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C. Brüggemann

Publications and source records attributed to C. Brüggemann.

2 recordsLinked to original sources

Selective spin wave excitation in ferromagnetic (Ga,Mn)As layers by picosecond strain pulses

We demonstrate selective excitation of a spin wave mode in a ferromagnetic (Ga,Mn)As film by picosecond strain pulses. For a certain range of magnetic fields applied in the layer plane only a single frequency is detected for the magnetization precession. We explain this selectivity of spin mode excitation by the necessity of spatial matching of magnon and phonon eigenfunctions, which represents a selection rule analogous to momentum conservation for magnon-phonon interaction in bulk ferromagnetic materials.

cond-mat.mtrl-sci↗

Coherent magnetization precession in ferromagnetic (Ga,Mn)As induced by picosecond acoustic pulses

We show that the magnetization of a thin ferromagnetic (Ga,Mn)As layer can be modulated by picosecond acoustic pulses. In this approach a picosecond strain pulse injected into the structure induces a tilt of the magnetization vector M, followed by the precession of M around its equilibrium orientation. This effect can be understood in terms of changes in magneto-crystalline anisotropy induced by the pulse. A model where only one anisotropy constant is affected by the strain pulse provides a good description of the observed time-dependent response.

cond-mat.mes-hall↗