ULTRAFAST ELECTRON SPIN DYNAMICS OF AS-GROWN Ga1-xMnxAs WITH APPROPRIATE Mn DOPING

Abstract

The electron spin dynamics in the as-grown Ga 1-x Mn x As films with appropriate Mn doping of x ~ 2–5% is studied using time-resolved magneto-optical Kerr effect measurements. Due to the existence of Mn interstitials, the s-d exchange scattering is found to play an important role for the as-grown Ga 1-x Mn x As , and compete with p-d exchange coupling to dominate the electron spin relaxation process. The contribution of electron–electron Coulomb scattering to the electron spin dynamics for the as-grown Ga 1-x Mn x As appears to be as important as that of the annealed ones. Our findings are fundamentally important for better understanding the electron spin dynamics in Ga 1-x Mn x As for its future spintronic applications.