We report dynamics of the transient polar Kerr rotation (KR) and of the transient reflectivity induced by femtosecond laser pulses in ferromagnetic (Ga,Mn)As with no external magnetic field applied. It is shown that the measured KR signal consist of several different contributions, among which only the oscillatory signal is directly connected with the ferromagnetic order in (Ga,Mn)As. The origin of the light-induced magnetization precession is discussed and the magnetization precession damping (Gilbert damping) is found to be strongly influenced by annealing of the sample.
@article{arxiv.0802.2043,
title = {Light-induced magnetization precession in GaMnAs},
author = {E. Rozkotova and P. Nemec and P. Horodyska and D. Sprinzl and F. Trojanek and P. Maly and V. Novak and K. Olejnik and M. Cukr and T. Jungwirth},
journal= {arXiv preprint arXiv:0802.2043},
year = {2009}
}
Comments
6 pages, 4 figures. accepted in Applied Physics Letters