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. 
M. Bombeck, A. S. Salasyuk, B. A. Glavin, A. V. Scherbakov, C.   Br\"uggemann, D. R. Yakovlev, V. F. Sapega, X. Liu, J. K. F...
cond-mat.mtrl-sci cond-mat.other