Spin dynamics of semiconductor electrons in a hybrid ferromagnet/semiconductor structure

We analyze the recent experimental study by R.J. Epstein et al. [Phys. Rev. B 65, 121202 (2002)] on the spin dynamics of semiconductor electrons in a hybrid ferromagnet/semiconductor structure by using a simple model based on the Bloch equations. A comparison between the model calculations and the experimental observations shows that the spin relaxation rate is strongly anisotropic. We interpret this anisotropy as a manifestation of the exchange interaction between metallic and semiconductor electrons at the ferromagnet/semiconductor interface.